| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * INET An implementation of the TCP/IP protocol suite for the LINUX |
| * operating system. INET is implemented using the BSD Socket |
| * interface as the means of communication with the user level. |
| * |
| * PACKET - implements raw packet sockets. |
| * |
| * Authors: Ross Biro |
| * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> |
| * Alan Cox, <gw4pts@gw4pts.ampr.org> |
| * |
| * Fixes: |
| * Alan Cox : verify_area() now used correctly |
| * Alan Cox : new skbuff lists, look ma no backlogs! |
| * Alan Cox : tidied skbuff lists. |
| * Alan Cox : Now uses generic datagram routines I |
| * added. Also fixed the peek/read crash |
| * from all old Linux datagram code. |
| * Alan Cox : Uses the improved datagram code. |
| * Alan Cox : Added NULL's for socket options. |
| * Alan Cox : Re-commented the code. |
| * Alan Cox : Use new kernel side addressing |
| * Rob Janssen : Correct MTU usage. |
| * Dave Platt : Counter leaks caused by incorrect |
| * interrupt locking and some slightly |
| * dubious gcc output. Can you read |
| * compiler: it said _VOLATILE_ |
| * Richard Kooijman : Timestamp fixes. |
| * Alan Cox : New buffers. Use sk->mac.raw. |
| * Alan Cox : sendmsg/recvmsg support. |
| * Alan Cox : Protocol setting support |
| * Alexey Kuznetsov : Untied from IPv4 stack. |
| * Cyrus Durgin : Fixed kerneld for kmod. |
| * Michal Ostrowski : Module initialization cleanup. |
| * Ulises Alonso : Frame number limit removal and |
| * packet_set_ring memory leak. |
| * Eric Biederman : Allow for > 8 byte hardware addresses. |
| * The convention is that longer addresses |
| * will simply extend the hardware address |
| * byte arrays at the end of sockaddr_ll |
| * and packet_mreq. |
| * Johann Baudy : Added TX RING. |
| * Chetan Loke : Implemented TPACKET_V3 block abstraction |
| * layer. |
| * Copyright (C) 2011, <lokec@ccs.neu.edu> |
| */ |
| |
| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| |
| #include <linux/ethtool.h> |
| #include <linux/types.h> |
| #include <linux/mm.h> |
| #include <linux/capability.h> |
| #include <linux/fcntl.h> |
| #include <linux/socket.h> |
| #include <linux/in.h> |
| #include <linux/inet.h> |
| #include <linux/netdevice.h> |
| #include <linux/if_packet.h> |
| #include <linux/wireless.h> |
| #include <linux/kernel.h> |
| #include <linux/kmod.h> |
| #include <linux/slab.h> |
| #include <linux/vmalloc.h> |
| #include <net/net_namespace.h> |
| #include <net/ip.h> |
| #include <net/protocol.h> |
| #include <linux/skbuff.h> |
| #include <net/sock.h> |
| #include <linux/errno.h> |
| #include <linux/timer.h> |
| #include <linux/uaccess.h> |
| #include <asm/ioctls.h> |
| #include <asm/page.h> |
| #include <asm/cacheflush.h> |
| #include <asm/io.h> |
| #include <linux/proc_fs.h> |
| #include <linux/seq_file.h> |
| #include <linux/poll.h> |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/mutex.h> |
| #include <linux/if_vlan.h> |
| #include <linux/virtio_net.h> |
| #include <linux/errqueue.h> |
| #include <linux/net_tstamp.h> |
| #include <linux/percpu.h> |
| #ifdef CONFIG_INET |
| #include <net/inet_common.h> |
| #endif |
| #include <linux/bpf.h> |
| #include <net/compat.h> |
| |
| #include "internal.h" |
| |
| /* |
| Assumptions: |
| - If the device has no dev->header_ops->create, there is no LL header |
| visible above the device. In this case, its hard_header_len should be 0. |
| The device may prepend its own header internally. In this case, its |
| needed_headroom should be set to the space needed for it to add its |
| internal header. |
| For example, a WiFi driver pretending to be an Ethernet driver should |
| set its hard_header_len to be the Ethernet header length, and set its |
| needed_headroom to be (the real WiFi header length - the fake Ethernet |
| header length). |
| - packet socket receives packets with pulled ll header, |
| so that SOCK_RAW should push it back. |
| |
| On receive: |
| ----------- |
| |
| Incoming, dev_has_header(dev) == true |
| mac_header -> ll header |
| data -> data |
| |
| Outgoing, dev_has_header(dev) == true |
| mac_header -> ll header |
| data -> ll header |
| |
| Incoming, dev_has_header(dev) == false |
| mac_header -> data |
| However drivers often make it point to the ll header. |
| This is incorrect because the ll header should be invisible to us. |
| data -> data |
| |
| Outgoing, dev_has_header(dev) == false |
| mac_header -> data. ll header is invisible to us. |
| data -> data |
| |
| Resume |
| If dev_has_header(dev) == false we are unable to restore the ll header, |
| because it is invisible to us. |
| |
| |
| On transmit: |
| ------------ |
| |
| dev_has_header(dev) == true |
| mac_header -> ll header |
| data -> ll header |
| |
| dev_has_header(dev) == false (ll header is invisible to us) |
| mac_header -> data |
| data -> data |
| |
| We should set network_header on output to the correct position, |
| packet classifier depends on it. |
| */ |
| |
| /* Private packet socket structures. */ |
| |
| /* identical to struct packet_mreq except it has |
| * a longer address field. |
| */ |
| struct packet_mreq_max { |
| int mr_ifindex; |
| unsigned short mr_type; |
| unsigned short mr_alen; |
| unsigned char mr_address[MAX_ADDR_LEN]; |
| }; |
| |
| union tpacket_uhdr { |
| struct tpacket_hdr *h1; |
| struct tpacket2_hdr *h2; |
| struct tpacket3_hdr *h3; |
| void *raw; |
| }; |
| |
| static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, |
| int closing, int tx_ring); |
| |
| #define V3_ALIGNMENT (8) |
| |
| #define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT)) |
| |
| #define BLK_PLUS_PRIV(sz_of_priv) \ |
| (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT)) |
| |
| #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status) |
| #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts) |
| #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt) |
| #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len) |
| #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num) |
| #define BLOCK_O2PRIV(x) ((x)->offset_to_priv) |
| |
| struct packet_sock; |
| static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, |
| struct packet_type *pt, struct net_device *orig_dev); |
| |
| static void *packet_previous_frame(struct packet_sock *po, |
| struct packet_ring_buffer *rb, |
| int status); |
| static void packet_increment_head(struct packet_ring_buffer *buff); |
| static int prb_curr_blk_in_use(struct tpacket_block_desc *); |
| static void *prb_dispatch_next_block(struct tpacket_kbdq_core *, |
| struct packet_sock *); |
| static void prb_retire_current_block(struct tpacket_kbdq_core *, |
| struct packet_sock *, unsigned int status); |
| static int prb_queue_frozen(struct tpacket_kbdq_core *); |
| static void prb_open_block(struct tpacket_kbdq_core *, |
| struct tpacket_block_desc *); |
| static void prb_retire_rx_blk_timer_expired(struct timer_list *); |
| static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *); |
| static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *); |
| static void prb_clear_rxhash(struct tpacket_kbdq_core *, |
| struct tpacket3_hdr *); |
| static void prb_fill_vlan_info(struct tpacket_kbdq_core *, |
| struct tpacket3_hdr *); |
| static void packet_flush_mclist(struct sock *sk); |
| static u16 packet_pick_tx_queue(struct sk_buff *skb); |
| |
| struct packet_skb_cb { |
| union { |
| struct sockaddr_pkt pkt; |
| union { |
| /* Trick: alias skb original length with |
| * ll.sll_family and ll.protocol in order |
| * to save room. |
| */ |
| unsigned int origlen; |
| struct sockaddr_ll ll; |
| }; |
| } sa; |
| }; |
| |
| #define vio_le() virtio_legacy_is_little_endian() |
| |
| #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb)) |
| |
| #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc)) |
| #define GET_PBLOCK_DESC(x, bid) \ |
| ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer)) |
| #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \ |
| ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer)) |
| #define GET_NEXT_PRB_BLK_NUM(x) \ |
| (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \ |
| ((x)->kactive_blk_num+1) : 0) |
| |
| static void __fanout_unlink(struct sock *sk, struct packet_sock *po); |
| static void __fanout_link(struct sock *sk, struct packet_sock *po); |
| |
| static int packet_direct_xmit(struct sk_buff *skb) |
| { |
| return dev_direct_xmit(skb, packet_pick_tx_queue(skb)); |
| } |
| |
| static struct net_device *packet_cached_dev_get(struct packet_sock *po) |
| { |
| struct net_device *dev; |
| |
| rcu_read_lock(); |
| dev = rcu_dereference(po->cached_dev); |
| dev_hold(dev); |
| rcu_read_unlock(); |
| |
| return dev; |
| } |
| |
| static void packet_cached_dev_assign(struct packet_sock *po, |
| struct net_device *dev) |
| { |
| rcu_assign_pointer(po->cached_dev, dev); |
| } |
| |
| static void packet_cached_dev_reset(struct packet_sock *po) |
| { |
| RCU_INIT_POINTER(po->cached_dev, NULL); |
| } |
| |
| static bool packet_use_direct_xmit(const struct packet_sock *po) |
| { |
| /* Paired with WRITE_ONCE() in packet_setsockopt() */ |
| return READ_ONCE(po->xmit) == packet_direct_xmit; |
| } |
| |
| static u16 packet_pick_tx_queue(struct sk_buff *skb) |
| { |
| struct net_device *dev = skb->dev; |
| const struct net_device_ops *ops = dev->netdev_ops; |
| int cpu = raw_smp_processor_id(); |
| u16 queue_index; |
| |
| #ifdef CONFIG_XPS |
| skb->sender_cpu = cpu + 1; |
| #endif |
| skb_record_rx_queue(skb, cpu % dev->real_num_tx_queues); |
| if (ops->ndo_select_queue) { |
| queue_index = ops->ndo_select_queue(dev, skb, NULL); |
| queue_index = netdev_cap_txqueue(dev, queue_index); |
| } else { |
| queue_index = netdev_pick_tx(dev, skb, NULL); |
| } |
| |
| return queue_index; |
| } |
| |
| /* __register_prot_hook must be invoked through register_prot_hook |
| * or from a context in which asynchronous accesses to the packet |
| * socket is not possible (packet_create()). |
| */ |
| static void __register_prot_hook(struct sock *sk) |
| { |
| struct packet_sock *po = pkt_sk(sk); |
| |
| if (!po->running) { |
| if (po->fanout) |
| __fanout_link(sk, po); |
| else |
| dev_add_pack(&po->prot_hook); |
| |
| sock_hold(sk); |
| po->running = 1; |
| } |
| } |
| |
| static void register_prot_hook(struct sock *sk) |
| { |
| lockdep_assert_held_once(&pkt_sk(sk)->bind_lock); |
| __register_prot_hook(sk); |
| } |
| |
| /* If the sync parameter is true, we will temporarily drop |
| * the po->bind_lock and do a synchronize_net to make sure no |
| * asynchronous packet processing paths still refer to the elements |
| * of po->prot_hook. If the sync parameter is false, it is the |
| * callers responsibility to take care of this. |
| */ |
| static void __unregister_prot_hook(struct sock *sk, bool sync) |
| { |
| struct packet_sock *po = pkt_sk(sk); |
| |
| lockdep_assert_held_once(&po->bind_lock); |
| |
| po->running = 0; |
| |
| if (po->fanout) |
| __fanout_unlink(sk, po); |
| else |
| __dev_remove_pack(&po->prot_hook); |
| |
| __sock_put(sk); |
| |
| if (sync) { |
| spin_unlock(&po->bind_lock); |
| synchronize_net(); |
| spin_lock(&po->bind_lock); |
| } |
| } |
| |
| static void unregister_prot_hook(struct sock *sk, bool sync) |
| { |
| struct packet_sock *po = pkt_sk(sk); |
| |
| if (po->running) |
| __unregister_prot_hook(sk, sync); |
| } |
| |
| static inline struct page * __pure pgv_to_page(void *addr) |
| { |
| if (is_vmalloc_addr(addr)) |
| return vmalloc_to_page(addr); |
| return virt_to_page(addr); |
| } |
| |
| static void __packet_set_status(struct packet_sock *po, void *frame, int status) |
| { |
| union tpacket_uhdr h; |
| |
| /* WRITE_ONCE() are paired with READ_ONCE() in __packet_get_status */ |
| |
| h.raw = frame; |
| switch (po->tp_version) { |
| case TPACKET_V1: |
| WRITE_ONCE(h.h1->tp_status, status); |
| flush_dcache_page(pgv_to_page(&h.h1->tp_status)); |
| break; |
| case TPACKET_V2: |
| WRITE_ONCE(h.h2->tp_status, status); |
| flush_dcache_page(pgv_to_page(&h.h2->tp_status)); |
| break; |
| case TPACKET_V3: |
| WRITE_ONCE(h.h3->tp_status, status); |
| flush_dcache_page(pgv_to_page(&h.h3->tp_status)); |
| break; |
| default: |
| WARN(1, "TPACKET version not supported.\n"); |
| BUG(); |
| } |
| |
| smp_wmb(); |
| } |
| |
| static int __packet_get_status(const struct packet_sock *po, void *frame) |
| { |
| union tpacket_uhdr h; |
| |
| smp_rmb(); |
| |
| /* READ_ONCE() are paired with WRITE_ONCE() in __packet_set_status */ |
| |
| h.raw = frame; |
| switch (po->tp_version) { |
| case TPACKET_V1: |
| flush_dcache_page(pgv_to_page(&h.h1->tp_status)); |
| return READ_ONCE(h.h1->tp_status); |
| case TPACKET_V2: |
| flush_dcache_page(pgv_to_page(&h.h2->tp_status)); |
| return READ_ONCE(h.h2->tp_status); |
| case TPACKET_V3: |
| flush_dcache_page(pgv_to_page(&h.h3->tp_status)); |
| return READ_ONCE(h.h3->tp_status); |
| default: |
| WARN(1, "TPACKET version not supported.\n"); |
| BUG(); |
| return 0; |
| } |
| } |
| |
| static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec64 *ts, |
| unsigned int flags) |
| { |
| struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); |
| |
| if (shhwtstamps && |
| (flags & SOF_TIMESTAMPING_RAW_HARDWARE) && |
| ktime_to_timespec64_cond(shhwtstamps->hwtstamp, ts)) |
| return TP_STATUS_TS_RAW_HARDWARE; |
| |
| if ((flags & SOF_TIMESTAMPING_SOFTWARE) && |
| ktime_to_timespec64_cond(skb->tstamp, ts)) |
| return TP_STATUS_TS_SOFTWARE; |
| |
| return 0; |
| } |
| |
| static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame, |
| struct sk_buff *skb) |
| { |
| union tpacket_uhdr h; |
| struct timespec64 ts; |
| __u32 ts_status; |
| |
| if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp))) |
| return 0; |
| |
| h.raw = frame; |
| /* |
| * versions 1 through 3 overflow the timestamps in y2106, since they |
| * all store the seconds in a 32-bit unsigned integer. |
| * If we create a version 4, that should have a 64-bit timestamp, |
| * either 64-bit seconds + 32-bit nanoseconds, or just 64-bit |
| * nanoseconds. |
| */ |
| switch (po->tp_version) { |
| case TPACKET_V1: |
| h.h1->tp_sec = ts.tv_sec; |
| h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; |
| break; |
| case TPACKET_V2: |
| h.h2->tp_sec = ts.tv_sec; |
| h.h2->tp_nsec = ts.tv_nsec; |
| break; |
| case TPACKET_V3: |
| h.h3->tp_sec = ts.tv_sec; |
| h.h3->tp_nsec = ts.tv_nsec; |
| break; |
| default: |
| WARN(1, "TPACKET version not supported.\n"); |
| BUG(); |
| } |
| |
| /* one flush is safe, as both fields always lie on the same cacheline */ |
| flush_dcache_page(pgv_to_page(&h.h1->tp_sec)); |
| smp_wmb(); |
| |
| return ts_status; |
| } |
| |
| static void *packet_lookup_frame(const struct packet_sock *po, |
| const struct packet_ring_buffer *rb, |
| unsigned int position, |
| int status) |
| { |
| unsigned int pg_vec_pos, frame_offset; |
| union tpacket_uhdr h; |
| |
| pg_vec_pos = position / rb->frames_per_block; |
| frame_offset = position % rb->frames_per_block; |
| |
| h.raw = rb->pg_vec[pg_vec_pos].buffer + |
| (frame_offset * rb->frame_size); |
| |
| if (status != __packet_get_status(po, h.raw)) |
| return NULL; |
| |
| return h.raw; |
| } |
| |
| static void *packet_current_frame(struct packet_sock *po, |
| struct packet_ring_buffer *rb, |
| int status) |
| { |
| return packet_lookup_frame(po, rb, rb->head, status); |
| } |
| |
| static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc) |
| { |
| del_timer_sync(&pkc->retire_blk_timer); |
| } |
| |
| static void prb_shutdown_retire_blk_timer(struct packet_sock *po, |
| struct sk_buff_head *rb_queue) |
| { |
| struct tpacket_kbdq_core *pkc; |
| |
| pkc = GET_PBDQC_FROM_RB(&po->rx_ring); |
| |
| spin_lock_bh(&rb_queue->lock); |
| pkc->delete_blk_timer = 1; |
| spin_unlock_bh(&rb_queue->lock); |
| |
| prb_del_retire_blk_timer(pkc); |
| } |
| |
| static void prb_setup_retire_blk_timer(struct packet_sock *po) |
| { |
| struct tpacket_kbdq_core *pkc; |
| |
| pkc = GET_PBDQC_FROM_RB(&po->rx_ring); |
| timer_setup(&pkc->retire_blk_timer, prb_retire_rx_blk_timer_expired, |
| 0); |
| pkc->retire_blk_timer.expires = jiffies; |
| } |
| |
| static int prb_calc_retire_blk_tmo(struct packet_sock *po, |
| int blk_size_in_bytes) |
| { |
| struct net_device *dev; |
| unsigned int mbits, div; |
| struct ethtool_link_ksettings ecmd; |
| int err; |
| |
| rtnl_lock(); |
| dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex); |
| if (unlikely(!dev)) { |
| rtnl_unlock(); |
| return DEFAULT_PRB_RETIRE_TOV; |
| } |
| err = __ethtool_get_link_ksettings(dev, &ecmd); |
| rtnl_unlock(); |
| if (err) |
| return DEFAULT_PRB_RETIRE_TOV; |
| |
| /* If the link speed is so slow you don't really |
| * need to worry about perf anyways |
| */ |
| if (ecmd.base.speed < SPEED_1000 || |
| ecmd.base.speed == SPEED_UNKNOWN) |
| return DEFAULT_PRB_RETIRE_TOV; |
| |
| div = ecmd.base.speed / 1000; |
| mbits = (blk_size_in_bytes * 8) / (1024 * 1024); |
| |
| if (div) |
| mbits /= div; |
| |
| if (div) |
| return mbits + 1; |
| return mbits; |
| } |
| |
| static void prb_init_ft_ops(struct tpacket_kbdq_core *p1, |
| union tpacket_req_u *req_u) |
| { |
| p1->feature_req_word = req_u->req3.tp_feature_req_word; |
| } |
| |
| static void init_prb_bdqc(struct packet_sock *po, |
| struct packet_ring_buffer *rb, |
| struct pgv *pg_vec, |
| union tpacket_req_u *req_u) |
| { |
| struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb); |
| struct tpacket_block_desc *pbd; |
| |
| memset(p1, 0x0, sizeof(*p1)); |
| |
| p1->knxt_seq_num = 1; |
| p1->pkbdq = pg_vec; |
| pbd = (struct tpacket_block_desc *)pg_vec[0].buffer; |
| p1->pkblk_start = pg_vec[0].buffer; |
| p1->kblk_size = req_u->req3.tp_block_size; |
| p1->knum_blocks = req_u->req3.tp_block_nr; |
| p1->hdrlen = po->tp_hdrlen; |
| p1->version = po->tp_version; |
| p1->last_kactive_blk_num = 0; |
| po->stats.stats3.tp_freeze_q_cnt = 0; |
| if (req_u->req3.tp_retire_blk_tov) |
| p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov; |
| else |
| p1->retire_blk_tov = prb_calc_retire_blk_tmo(po, |
| req_u->req3.tp_block_size); |
| p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov); |
| p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv; |
| rwlock_init(&p1->blk_fill_in_prog_lock); |
| |
| p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv); |
| prb_init_ft_ops(p1, req_u); |
| prb_setup_retire_blk_timer(po); |
| prb_open_block(p1, pbd); |
| } |
| |
| /* Do NOT update the last_blk_num first. |
| * Assumes sk_buff_head lock is held. |
| */ |
| static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc) |
| { |
| mod_timer(&pkc->retire_blk_timer, |
| jiffies + pkc->tov_in_jiffies); |
| pkc->last_kactive_blk_num = pkc->kactive_blk_num; |
| } |
| |
| /* |
| * Timer logic: |
| * 1) We refresh the timer only when we open a block. |
| * By doing this we don't waste cycles refreshing the timer |
| * on packet-by-packet basis. |
| * |
| * With a 1MB block-size, on a 1Gbps line, it will take |
| * i) ~8 ms to fill a block + ii) memcpy etc. |
| * In this cut we are not accounting for the memcpy time. |
| * |
| * So, if the user sets the 'tmo' to 10ms then the timer |
| * will never fire while the block is still getting filled |
| * (which is what we want). However, the user could choose |
| * to close a block early and that's fine. |
| * |
| * But when the timer does fire, we check whether or not to refresh it. |
| * Since the tmo granularity is in msecs, it is not too expensive |
| * to refresh the timer, lets say every '8' msecs. |
| * Either the user can set the 'tmo' or we can derive it based on |
| * a) line-speed and b) block-size. |
| * prb_calc_retire_blk_tmo() calculates the tmo. |
| * |
| */ |
| static void prb_retire_rx_blk_timer_expired(struct timer_list *t) |
| { |
| struct packet_sock *po = |
| from_timer(po, t, rx_ring.prb_bdqc.retire_blk_timer); |
| struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring); |
| unsigned int frozen; |
| struct tpacket_block_desc *pbd; |
| |
| spin_lock(&po->sk.sk_receive_queue.lock); |
| |
| frozen = prb_queue_frozen(pkc); |
| pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); |
| |
| if (unlikely(pkc->delete_blk_timer)) |
| goto out; |
| |
| /* We only need to plug the race when the block is partially filled. |
| * tpacket_rcv: |
| * lock(); increment BLOCK_NUM_PKTS; unlock() |
| * copy_bits() is in progress ... |
| * timer fires on other cpu: |
| * we can't retire the current block because copy_bits |
| * is in progress. |
| * |
| */ |
| if (BLOCK_NUM_PKTS(pbd)) { |
| /* Waiting for skb_copy_bits to finish... */ |
| write_lock(&pkc->blk_fill_in_prog_lock); |
| write_unlock(&pkc->blk_fill_in_prog_lock); |
| } |
| |
| if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) { |
| if (!frozen) { |
| if (!BLOCK_NUM_PKTS(pbd)) { |
| /* An empty block. Just refresh the timer. */ |
| goto refresh_timer; |
| } |
| prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO); |
| if (!prb_dispatch_next_block(pkc, po)) |
| goto refresh_timer; |
| else |
| goto out; |
| } else { |
| /* Case 1. Queue was frozen because user-space was |
| * lagging behind. |
| */ |
| if (prb_curr_blk_in_use(pbd)) { |
| /* |
| * Ok, user-space is still behind. |
| * So just refresh the timer. |
| */ |
| goto refresh_timer; |
| } else { |
| /* Case 2. queue was frozen,user-space caught up, |
| * now the link went idle && the timer fired. |
| * We don't have a block to close.So we open this |
| * block and restart the timer. |
| * opening a block thaws the queue,restarts timer |
| * Thawing/timer-refresh is a side effect. |
| */ |
| prb_open_block(pkc, pbd); |
| goto out; |
| } |
| } |
| } |
| |
| refresh_timer: |
| _prb_refresh_rx_retire_blk_timer(pkc); |
| |
| out: |
| spin_unlock(&po->sk.sk_receive_queue.lock); |
| } |
| |
| static void prb_flush_block(struct tpacket_kbdq_core *pkc1, |
| struct tpacket_block_desc *pbd1, __u32 status) |
| { |
| /* Flush everything minus the block header */ |
| |
| #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 |
| u8 *start, *end; |
| |
| start = (u8 *)pbd1; |
| |
| /* Skip the block header(we know header WILL fit in 4K) */ |
| start += PAGE_SIZE; |
| |
| end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end); |
| for (; start < end; start += PAGE_SIZE) |
| flush_dcache_page(pgv_to_page(start)); |
| |
| smp_wmb(); |
| #endif |
| |
| /* Now update the block status. */ |
| |
| BLOCK_STATUS(pbd1) = status; |
| |
| /* Flush the block header */ |
| |
| #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 |
| start = (u8 *)pbd1; |
| flush_dcache_page(pgv_to_page(start)); |
| |
| smp_wmb(); |
| #endif |
| } |
| |
| /* |
| * Side effect: |
| * |
| * 1) flush the block |
| * 2) Increment active_blk_num |
| * |
| * Note:We DONT refresh the timer on purpose. |
| * Because almost always the next block will be opened. |
| */ |
| static void prb_close_block(struct tpacket_kbdq_core *pkc1, |
| struct tpacket_block_desc *pbd1, |
| struct packet_sock *po, unsigned int stat) |
| { |
| __u32 status = TP_STATUS_USER | stat; |
| |
| struct tpacket3_hdr *last_pkt; |
| struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; |
| struct sock *sk = &po->sk; |
| |
| if (atomic_read(&po->tp_drops)) |
| status |= TP_STATUS_LOSING; |
| |
| last_pkt = (struct tpacket3_hdr *)pkc1->prev; |
| last_pkt->tp_next_offset = 0; |
| |
| /* Get the ts of the last pkt */ |
| if (BLOCK_NUM_PKTS(pbd1)) { |
| h1->ts_last_pkt.ts_sec = last_pkt->tp_sec; |
| h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec; |
| } else { |
| /* Ok, we tmo'd - so get the current time. |
| * |
| * It shouldn't really happen as we don't close empty |
| * blocks. See prb_retire_rx_blk_timer_expired(). |
| */ |
| struct timespec64 ts; |
| ktime_get_real_ts64(&ts); |
| h1->ts_last_pkt.ts_sec = ts.tv_sec; |
| h1->ts_last_pkt.ts_nsec = ts.tv_nsec; |
| } |
| |
| smp_wmb(); |
| |
| /* Flush the block */ |
| prb_flush_block(pkc1, pbd1, status); |
| |
| sk->sk_data_ready(sk); |
| |
| pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1); |
| } |
| |
| static void prb_thaw_queue(struct tpacket_kbdq_core *pkc) |
| { |
| pkc->reset_pending_on_curr_blk = 0; |
| } |
| |
| /* |
| * Side effect of opening a block: |
| * |
| * 1) prb_queue is thawed. |
| * 2) retire_blk_timer is refreshed. |
| * |
| */ |
| static void prb_open_block(struct tpacket_kbdq_core *pkc1, |
| struct tpacket_block_desc *pbd1) |
| { |
| struct timespec64 ts; |
| struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; |
| |
| smp_rmb(); |
| |
| /* We could have just memset this but we will lose the |
| * flexibility of making the priv area sticky |
| */ |
| |
| BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++; |
| BLOCK_NUM_PKTS(pbd1) = 0; |
| BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); |
| |
| ktime_get_real_ts64(&ts); |
| |
| h1->ts_first_pkt.ts_sec = ts.tv_sec; |
| h1->ts_first_pkt.ts_nsec = ts.tv_nsec; |
| |
| pkc1->pkblk_start = (char *)pbd1; |
| pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); |
| |
| BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); |
| BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN; |
| |
| pbd1->version = pkc1->version; |
| pkc1->prev = pkc1->nxt_offset; |
| pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size; |
| |
| prb_thaw_queue(pkc1); |
| _prb_refresh_rx_retire_blk_timer(pkc1); |
| |
| smp_wmb(); |
| } |
| |
| /* |
| * Queue freeze logic: |
| * 1) Assume tp_block_nr = 8 blocks. |
| * 2) At time 't0', user opens Rx ring. |
| * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7 |
| * 4) user-space is either sleeping or processing block '0'. |
| * 5) tpacket_rcv is currently filling block '7', since there is no space left, |
| * it will close block-7,loop around and try to fill block '0'. |
| * call-flow: |
| * __packet_lookup_frame_in_block |
| * prb_retire_current_block() |
| * prb_dispatch_next_block() |
| * |->(BLOCK_STATUS == USER) evaluates to true |
| * 5.1) Since block-0 is currently in-use, we just freeze the queue. |
| * 6) Now there are two cases: |
| * 6.1) Link goes idle right after the queue is frozen. |
| * But remember, the last open_block() refreshed the timer. |
| * When this timer expires,it will refresh itself so that we can |
| * re-open block-0 in near future. |
| * 6.2) Link is busy and keeps on receiving packets. This is a simple |
| * case and __packet_lookup_frame_in_block will check if block-0 |
| * is free and can now be re-used. |
| */ |
| static void prb_freeze_queue(struct tpacket_kbdq_core *pkc, |
| struct packet_sock *po) |
| { |
| pkc->reset_pending_on_curr_blk = 1; |
| po->stats.stats3.tp_freeze_q_cnt++; |
| } |
| |
| #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT)) |
| |
| /* |
| * If the next block is free then we will dispatch it |
| * and return a good offset. |
| * Else, we will freeze the queue. |
| * So, caller must check the return value. |
| */ |
| static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc, |
| struct packet_sock *po) |
| { |
| struct tpacket_block_desc *pbd; |
| |
| smp_rmb(); |
| |
| /* 1. Get current block num */ |
| pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); |
| |
| /* 2. If this block is currently in_use then freeze the queue */ |
| if (TP_STATUS_USER & BLOCK_STATUS(pbd)) { |
| prb_freeze_queue(pkc, po); |
| return NULL; |
| } |
| |
| /* |
| * 3. |
| * open this block and return the offset where the first packet |
| * needs to get stored. |
| */ |
| prb_open_block(pkc, pbd); |
| return (void *)pkc->nxt_offset; |
| } |
| |
| static void prb_retire_current_block(struct tpacket_kbdq_core *pkc, |
| struct packet_sock *po, unsigned int status) |
| { |
| struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); |
| |
| /* retire/close the current block */ |
| if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) { |
| /* |
| * Plug the case where copy_bits() is in progress on |
| * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't |
| * have space to copy the pkt in the current block and |
| * called prb_retire_current_block() |
| * |
| * We don't need to worry about the TMO case because |
| * the timer-handler already handled this case. |
| */ |
| if (!(status & TP_STATUS_BLK_TMO)) { |
| /* Waiting for skb_copy_bits to finish... */ |
| write_lock(&pkc->blk_fill_in_prog_lock); |
| write_unlock(&pkc->blk_fill_in_prog_lock); |
| } |
| prb_close_block(pkc, pbd, po, status); |
| return; |
| } |
| } |
| |
| static int prb_curr_blk_in_use(struct tpacket_block_desc *pbd) |
| { |
| return TP_STATUS_USER & BLOCK_STATUS(pbd); |
| } |
| |
| static int prb_queue_frozen(struct tpacket_kbdq_core *pkc) |
| { |
| return pkc->reset_pending_on_curr_blk; |
| } |
| |
| static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb) |
| __releases(&pkc->blk_fill_in_prog_lock) |
| { |
| struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); |
| |
| read_unlock(&pkc->blk_fill_in_prog_lock); |
| } |
| |
| static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc, |
| struct tpacket3_hdr *ppd) |
| { |
| ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb); |
| } |
| |
| static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc, |
| struct tpacket3_hdr *ppd) |
| { |
| ppd->hv1.tp_rxhash = 0; |
| } |
| |
| static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc, |
| struct tpacket3_hdr *ppd) |
| { |
| if (skb_vlan_tag_present(pkc->skb)) { |
| ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb); |
| ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto); |
| ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; |
| } else { |
| ppd->hv1.tp_vlan_tci = 0; |
| ppd->hv1.tp_vlan_tpid = 0; |
| ppd->tp_status = TP_STATUS_AVAILABLE; |
| } |
| } |
| |
| static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc, |
| struct tpacket3_hdr *ppd) |
| { |
| ppd->hv1.tp_padding = 0; |
| prb_fill_vlan_info(pkc, ppd); |
| |
| if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH) |
| prb_fill_rxhash(pkc, ppd); |
| else |
| prb_clear_rxhash(pkc, ppd); |
| } |
| |
| static void prb_fill_curr_block(char *curr, |
| struct tpacket_kbdq_core *pkc, |
| struct tpacket_block_desc *pbd, |
| unsigned int len) |
| __acquires(&pkc->blk_fill_in_prog_lock) |
| { |
| struct tpacket3_hdr *ppd; |
| |
| ppd = (struct tpacket3_hdr *)curr; |
| ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len); |
| pkc->prev = curr; |
| pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len); |
| BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len); |
| BLOCK_NUM_PKTS(pbd) += 1; |
| read_lock(&pkc->blk_fill_in_prog_lock); |
| prb_run_all_ft_ops(pkc, ppd); |
| } |
| |
| /* Assumes caller has the sk->rx_queue.lock */ |
| static void *__packet_lookup_frame_in_block(struct packet_sock *po, |
| struct sk_buff *skb, |
| unsigned int len |
| ) |
| { |
| struct tpacket_kbdq_core *pkc; |
| struct tpacket_block_desc *pbd; |
| char *curr, *end; |
| |
| pkc = GET_PBDQC_FROM_RB(&po->rx_ring); |
| pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); |
| |
| /* Queue is frozen when user space is lagging behind */ |
| if (prb_queue_frozen(pkc)) { |
| /* |
| * Check if that last block which caused the queue to freeze, |
| * is still in_use by user-space. |
| */ |
| if (prb_curr_blk_in_use(pbd)) { |
| /* Can't record this packet */ |
| return NULL; |
| } else { |
| /* |
| * Ok, the block was released by user-space. |
| * Now let's open that block. |
| * opening a block also thaws the queue. |
| * Thawing is a side effect. |
| */ |
| prb_open_block(pkc, pbd); |
| } |
| } |
| |
| smp_mb(); |
| curr = pkc->nxt_offset; |
| pkc->skb = skb; |
| end = (char *)pbd + pkc->kblk_size; |
| |
| /* first try the current block */ |
| if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) { |
| prb_fill_curr_block(curr, pkc, pbd, len); |
| return (void *)curr; |
| } |
| |
| /* Ok, close the current block */ |
| prb_retire_current_block(pkc, po, 0); |
| |
| /* Now, try to dispatch the next block */ |
| curr = (char *)prb_dispatch_next_block(pkc, po); |
| if (curr) { |
| pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); |
| prb_fill_curr_block(curr, pkc, pbd, len); |
| return (void *)curr; |
| } |
| |
| /* |
| * No free blocks are available.user_space hasn't caught up yet. |
| * Queue was just frozen and now this packet will get dropped. |
| */ |
| return NULL; |
| } |
| |
| static void *packet_current_rx_frame(struct packet_sock *po, |
| struct sk_buff *skb, |
| int status, unsigned int len) |
| { |
| char *curr = NULL; |
| switch (po->tp_version) { |
| case TPACKET_V1: |
| case TPACKET_V2: |
| curr = packet_lookup_frame(po, &po->rx_ring, |
| po->rx_ring.head, status); |
| return curr; |
| case TPACKET_V3: |
| return __packet_lookup_frame_in_block(po, skb, len); |
| default: |
| WARN(1, "TPACKET version not supported\n"); |
| BUG(); |
| return NULL; |
| } |
| } |
| |
| static void *prb_lookup_block(const struct packet_sock *po, |
| const struct packet_ring_buffer *rb, |
| unsigned int idx, |
| int status) |
| { |
| struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); |
| struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx); |
| |
| if (status != BLOCK_STATUS(pbd)) |
| return NULL; |
| return pbd; |
| } |
| |
| static int prb_previous_blk_num(struct packet_ring_buffer *rb) |
| { |
| unsigned int prev; |
| if (rb->prb_bdqc.kactive_blk_num) |
| prev = rb->prb_bdqc.kactive_blk_num-1; |
| else |
| prev = rb->prb_bdqc.knum_blocks-1; |
| return prev; |
| } |
| |
| /* Assumes caller has held the rx_queue.lock */ |
| static void *__prb_previous_block(struct packet_sock *po, |
| struct packet_ring_buffer *rb, |
| int status) |
| { |
| unsigned int previous = prb_previous_blk_num(rb); |
| return prb_lookup_block(po, rb, previous, status); |
| } |
| |
| static void *packet_previous_rx_frame(struct packet_sock *po, |
| struct packet_ring_buffer *rb, |
| int status) |
| { |
| if (po->tp_version <= TPACKET_V2) |
| return packet_previous_frame(po, rb, status); |
| |
| return __prb_previous_block(po, rb, status); |
| } |
| |
| static void packet_increment_rx_head(struct packet_sock *po, |
| struct packet_ring_buffer *rb) |
| { |
| switch (po->tp_version) { |
| case TPACKET_V1: |
| case TPACKET_V2: |
| return packet_increment_head(rb); |
| case TPACKET_V3: |
| default: |
| WARN(1, "TPACKET version not supported.\n"); |
| BUG(); |
| return; |
| } |
| } |
| |
| static void *packet_previous_frame(struct packet_sock *po, |
| struct packet_ring_buffer *rb, |
| int status) |
| { |
| unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max; |
| return packet_lookup_frame(po, rb, previous, status); |
| } |
| |
| static void packet_increment_head(struct packet_ring_buffer *buff) |
| { |
| buff->head = buff->head != buff->frame_max ? buff->head+1 : 0; |
| } |
| |
| static void packet_inc_pending(struct packet_ring_buffer *rb) |
| { |
| this_cpu_inc(*rb->pending_refcnt); |
| } |
| |
| static void packet_dec_pending(struct packet_ring_buffer *rb) |
| { |
| this_cpu_dec(*rb->pending_refcnt); |
| } |
| |
| static unsigned int packet_read_pending(const struct packet_ring_buffer *rb) |
| { |
| unsigned int refcnt = 0; |
| int cpu; |
| |
| /* We don't use pending refcount in rx_ring. */ |
| if (rb->pending_refcnt == NULL) |
| return 0; |
| |
| for_each_possible_cpu(cpu) |
| refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu); |
| |
| return refcnt; |
| } |
| |
| static int packet_alloc_pending(struct packet_sock *po) |
| { |
| po->rx_ring.pending_refcnt = NULL; |
| |
| po->tx_ring.pending_refcnt = alloc_percpu(unsigned int); |
| if (unlikely(po->tx_ring.pending_refcnt == NULL)) |
| return -ENOBUFS; |
| |
| return 0; |
| } |
| |
| static void packet_free_pending(struct packet_sock *po) |
| { |
| free_percpu(po->tx_ring.pending_refcnt); |
| } |
| |
| #define ROOM_POW_OFF 2 |
| #define ROOM_NONE 0x0 |
| #define ROOM_LOW 0x1 |
| #define ROOM_NORMAL 0x2 |
| |
| static bool __tpacket_has_room(const struct packet_sock *po, int pow_off) |
| { |
| int idx, len; |
| |
| len = READ_ONCE(po->rx_ring.frame_max) + 1; |
| idx = READ_ONCE(po->rx_ring.head); |
| if (pow_off) |
| idx += len >> pow_off; |
| if (idx >= len) |
| idx -= len; |
| return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL); |
| } |
| |
| static bool __tpacket_v3_has_room(const struct packet_sock *po, int pow_off) |
| { |
| int idx, len; |
| |
| len = READ_ONCE(po->rx_ring.prb_bdqc.knum_blocks); |
| idx = READ_ONCE(po->rx_ring.prb_bdqc.kactive_blk_num); |
| if (pow_off) |
| idx += len >> pow_off; |
| if (idx >= len) |
| idx -= len; |
| return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL); |
| } |
| |
| static int __packet_rcv_has_room(const struct packet_sock *po, |
| const struct sk_buff *skb) |
| { |
| const struct sock *sk = &po->sk; |
| int ret = ROOM_NONE; |
| |
| if (po->prot_hook.func != tpacket_rcv) { |
| int rcvbuf = READ_ONCE(sk->sk_rcvbuf); |
| int avail = rcvbuf - atomic_read(&sk->sk_rmem_alloc) |
| - (skb ? skb->truesize : 0); |
| |
| if (avail > (rcvbuf >> ROOM_POW_OFF)) |
| return ROOM_NORMAL; |
| else if (avail > 0) |
| return ROOM_LOW; |
| else |
| return ROOM_NONE; |
| } |
| |
| if (po->tp_version == TPACKET_V3) { |
| if (__tpacket_v3_has_room(po, ROOM_POW_OFF)) |
| ret = ROOM_NORMAL; |
| else if (__tpacket_v3_has_room(po, 0)) |
| ret = ROOM_LOW; |
| } else { |
| if (__tpacket_has_room(po, ROOM_POW_OFF)) |
| ret = ROOM_NORMAL; |
| else if (__tpacket_has_room(po, 0)) |
| ret = ROOM_LOW; |
| } |
| |
| return ret; |
| } |
| |
| static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb) |
| { |
| int pressure, ret; |
| |
| ret = __packet_rcv_has_room(po, skb); |
| pressure = ret != ROOM_NORMAL; |
| |
| if (READ_ONCE(po->pressure) != pressure) |
| WRITE_ONCE(po->pressure, pressure); |
| |
| return ret; |
| } |
| |
| static void packet_rcv_try_clear_pressure(struct packet_sock *po) |
| { |
| if (READ_ONCE(po->pressure) && |
| __packet_rcv_has_room(po, NULL) == ROOM_NORMAL) |
| WRITE_ONCE(po->pressure, 0); |
| } |
| |
| static void packet_sock_destruct(struct sock *sk) |
| { |
| skb_queue_purge(&sk->sk_error_queue); |
| |
| WARN_ON(atomic_read(&sk->sk_rmem_alloc)); |
| WARN_ON(refcount_read(&sk->sk_wmem_alloc)); |
| |
| if (!sock_flag(sk, SOCK_DEAD)) { |
| pr_err("Attempt to release alive packet socket: %p\n", sk); |
| return; |
| } |
| |
| sk_refcnt_debug_dec(sk); |
| } |
| |
| static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb) |
| { |
| u32 *history = po->rollover->history; |
| u32 victim, rxhash; |
| int i, count = 0; |
| |
| rxhash = skb_get_hash(skb); |
| for (i = 0; i < ROLLOVER_HLEN; i++) |
| if (READ_ONCE(history[i]) == rxhash) |
| count++; |
| |
| victim = prandom_u32() % ROLLOVER_HLEN; |
| |
| /* Avoid dirtying the cache line if possible */ |
| if (READ_ONCE(history[victim]) != rxhash) |
| WRITE_ONCE(history[victim], rxhash); |
| |
| return count > (ROLLOVER_HLEN >> 1); |
| } |
| |
| static unsigned int fanout_demux_hash(struct packet_fanout *f, |
| struct sk_buff *skb, |
| unsigned int num) |
| { |
| return reciprocal_scale(__skb_get_hash_symmetric(skb), num); |
| } |
| |
| static unsigned int fanout_demux_lb(struct packet_fanout *f, |
| struct sk_buff *skb, |
| unsigned int num) |
| { |
| unsigned int val = atomic_inc_return(&f->rr_cur); |
| |
| return val % num; |
| } |
| |
| static unsigned int fanout_demux_cpu(struct packet_fanout *f, |
| struct sk_buff *skb, |
| unsigned int num) |
| { |
| return smp_processor_id() % num; |
| } |
| |
| static unsigned int fanout_demux_rnd(struct packet_fanout *f, |
| struct sk_buff *skb, |
| unsigned int num) |
| { |
| return prandom_u32_max(num); |
| } |
| |
| static unsigned int fanout_demux_rollover(struct packet_fanout *f, |
| struct sk_buff *skb, |
| unsigned int idx, bool try_self, |
| unsigned int num) |
| { |
| struct packet_sock *po, *po_next, *po_skip = NULL; |
| unsigned int i, j, room = ROOM_NONE; |
| |
| po = pkt_sk(rcu_dereference(f->arr[idx])); |
| |
| if (try_self) { |
| room = packet_rcv_has_room(po, skb); |
| if (room == ROOM_NORMAL || |
| (room == ROOM_LOW && !fanout_flow_is_huge(po, skb))) |
| return idx; |
| po_skip = po; |
| } |
| |
| i = j = min_t(int, po->rollover->sock, num - 1); |
| do { |
| po_next = pkt_sk(rcu_dereference(f->arr[i])); |
| if (po_next != po_skip && !READ_ONCE(po_next->pressure) && |
| packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) { |
| if (i != j) |
| po->rollover->sock = i; |
| atomic_long_inc(&po->rollover->num); |
| if (room == ROOM_LOW) |
| atomic_long_inc(&po->rollover->num_huge); |
| return i; |
| } |
| |
| if (++i == num) |
| i = 0; |
| } while (i != j); |
| |
| atomic_long_inc(&po->rollover->num_failed); |
| return idx; |
| } |
| |
| static unsigned int fanout_demux_qm(struct packet_fanout *f, |
| struct sk_buff *skb, |
| unsigned int num) |
| { |
| return skb_get_queue_mapping(skb) % num; |
| } |
| |
| static unsigned int fanout_demux_bpf(struct packet_fanout *f, |
| struct sk_buff *skb, |
| unsigned int num) |
| { |
| struct bpf_prog *prog; |
| unsigned int ret = 0; |
| |
| rcu_read_lock(); |
| prog = rcu_dereference(f->bpf_prog); |
| if (prog) |
| ret = bpf_prog_run_clear_cb(prog, skb) % num; |
| rcu_read_unlock(); |
| |
| return ret; |
| } |
| |
| static bool fanout_has_flag(struct packet_fanout *f, u16 flag) |
| { |
| return f->flags & (flag >> 8); |
| } |
| |
| static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, |
| struct packet_type *pt, struct net_device *orig_dev) |
| { |
| struct packet_fanout *f = pt->af_packet_priv; |
| unsigned int num = READ_ONCE(f->num_members); |
| struct net *net = read_pnet(&f->net); |
| struct packet_sock *po; |
| unsigned int idx; |
| |
| if (!net_eq(dev_net(dev), net) || !num) { |
| kfree_skb(skb); |
| return 0; |
| } |
| |
| if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) { |
| skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET); |
| if (!skb) |
| return 0; |
| } |
| switch (f->type) { |
| case PACKET_FANOUT_HASH: |
| default: |
| idx = fanout_demux_hash(f, skb, num); |
| break; |
| case PACKET_FANOUT_LB: |
| idx = fanout_demux_lb(f, skb, num); |
| break; |
| case PACKET_FANOUT_CPU: |
| idx = fanout_demux_cpu(f, skb, num); |
| break; |
| case PACKET_FANOUT_RND: |
| idx = fanout_demux_rnd(f, skb, num); |
| break; |
| case PACKET_FANOUT_QM: |
| idx = fanout_demux_qm(f, skb, num); |
| break; |
| case PACKET_FANOUT_ROLLOVER: |
| idx = fanout_demux_rollover(f, skb, 0, false, num); |
| break; |
| case PACKET_FANOUT_CBPF: |
| case PACKET_FANOUT_EBPF: |
| idx = fanout_demux_bpf(f, skb, num); |
| break; |
| } |
| |
| if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER)) |
| idx = fanout_demux_rollover(f, skb, idx, true, num); |
| |
| po = pkt_sk(rcu_dereference(f->arr[idx])); |
| return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev); |
| } |
| |
| DEFINE_MUTEX(fanout_mutex); |
| EXPORT_SYMBOL_GPL(fanout_mutex); |
| static LIST_HEAD(fanout_list); |
| static u16 fanout_next_id; |
| |
| static void __fanout_link(struct sock *sk, struct packet_sock *po) |
| { |
| struct packet_fanout *f = po->fanout; |
| |
| spin_lock(&f->lock); |
| rcu_assign_pointer(f->arr[f->num_members], sk); |
| smp_wmb(); |
| f->num_members++; |
| if (f->num_members == 1) |
| dev_add_pack(&f->prot_hook); |
| spin_unlock(&f->lock); |
| } |
| |
| static void __fanout_unlink(struct sock *sk, struct packet_sock *po) |
| { |
| struct packet_fanout *f = po->fanout; |
| int i; |
| |
| spin_lock(&f->lock); |
| for (i = 0; i < f->num_members; i++) { |
| if (rcu_dereference_protected(f->arr[i], |
| lockdep_is_held(&f->lock)) == sk) |
| break; |
| } |
| BUG_ON(i >= f->num_members); |
| rcu_assign_pointer(f->arr[i], |
| rcu_dereference_protected(f->arr[f->num_members - 1], |
| lockdep_is_held(&f->lock))); |
| f->num_members--; |
| if (f->num_members == 0) |
| __dev_remove_pack(&f->prot_hook); |
| spin_unlock(&f->lock); |
| } |
| |
| static bool match_fanout_group(struct packet_type *ptype, struct sock *sk) |
| { |
| if (sk->sk_family != PF_PACKET) |
| return false; |
| |
| return ptype->af_packet_priv == pkt_sk(sk)->fanout; |
| } |
| |
| static void fanout_init_data(struct packet_fanout *f) |
| { |
| switch (f->type) { |
| case PACKET_FANOUT_LB: |
| atomic_set(&f->rr_cur, 0); |
| break; |
| case PACKET_FANOUT_CBPF: |
| case PACKET_FANOUT_EBPF: |
| RCU_INIT_POINTER(f->bpf_prog, NULL); |
| break; |
| } |
| } |
| |
| static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new) |
| { |
| struct bpf_prog *old; |
| |
| spin_lock(&f->lock); |
| old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock)); |
| rcu_assign_pointer(f->bpf_prog, new); |
| spin_unlock(&f->lock); |
| |
| if (old) { |
| synchronize_net(); |
| bpf_prog_destroy(old); |
| } |
| } |
| |
| static int fanout_set_data_cbpf(struct packet_sock *po, sockptr_t data, |
| unsigned int len) |
| { |
| struct bpf_prog *new; |
| struct sock_fprog fprog; |
| int ret; |
| |
| if (sock_flag(&po->sk, SOCK_FILTER_LOCKED)) |
| return -EPERM; |
| |
| ret = copy_bpf_fprog_from_user(&fprog, data, len); |
| if (ret) |
| return ret; |
| |
| ret = bpf_prog_create_from_user(&new, &fprog, NULL, false); |
| if (ret) |
| return ret; |
| |
| __fanout_set_data_bpf(po->fanout, new); |
| return 0; |
| } |
| |
| static int fanout_set_data_ebpf(struct packet_sock *po, sockptr_t data, |
| unsigned int len) |
| { |
| struct bpf_prog *new; |
| u32 fd; |
| |
| if (sock_flag(&po->sk, SOCK_FILTER_LOCKED)) |
| return -EPERM; |
| if (len != sizeof(fd)) |
| return -EINVAL; |
| if (copy_from_sockptr(&fd, data, len)) |
| return -EFAULT; |
| |
| new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER); |
| if (IS_ERR(new)) |
| return PTR_ERR(new); |
| |
| __fanout_set_data_bpf(po->fanout, new); |
| return 0; |
| } |
| |
| static int fanout_set_data(struct packet_sock *po, sockptr_t data, |
| unsigned int len) |
| { |
| switch (po->fanout->type) { |
| case PACKET_FANOUT_CBPF: |
| return fanout_set_data_cbpf(po, data, len); |
| case PACKET_FANOUT_EBPF: |
| return fanout_set_data_ebpf(po, data, len); |
| default: |
| return -EINVAL; |
| } |
| } |
| |
| static void fanout_release_data(struct packet_fanout *f) |
| { |
| switch (f->type) { |
| case PACKET_FANOUT_CBPF: |
| case PACKET_FANOUT_EBPF: |
| __fanout_set_data_bpf(f, NULL); |
| } |
| } |
| |
| static bool __fanout_id_is_free(struct sock *sk, u16 candidate_id) |
| { |
| struct packet_fanout *f; |
| |
| list_for_each_entry(f, &fanout_list, list) { |
| if (f->id == candidate_id && |
| read_pnet(&f->net) == sock_net(sk)) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| static bool fanout_find_new_id(struct sock *sk, u16 *new_id) |
| { |
| u16 id = fanout_next_id; |
| |
| do { |
| if (__fanout_id_is_free(sk, id)) { |
| *new_id = id; |
| fanout_next_id = id + 1; |
| return true; |
| } |
| |
| id++; |
| } while (id != fanout_next_id); |
| |
| return false; |
| } |
| |
| static int fanout_add(struct sock *sk, struct fanout_args *args) |
| { |
| struct packet_rollover *rollover = NULL; |
| struct packet_sock *po = pkt_sk(sk); |
| u16 type_flags = args->type_flags; |
| struct packet_fanout *f, *match; |
| u8 type = type_flags & 0xff; |
| u8 flags = type_flags >> 8; |
| u16 id = args->id; |
| int err; |
| |
| switch (type) { |
| case PACKET_FANOUT_ROLLOVER: |
| if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER) |
| return -EINVAL; |
| break; |
| case PACKET_FANOUT_HASH: |
| case PACKET_FANOUT_LB: |
| case PACKET_FANOUT_CPU: |
| case PACKET_FANOUT_RND: |
| case PACKET_FANOUT_QM: |
| case PACKET_FANOUT_CBPF: |
| case PACKET_FANOUT_EBPF: |
| break; |
| default: |
| return -EINVAL; |
| } |
| |
| mutex_lock(&fanout_mutex); |
| |
| err = -EALREADY; |
| if (po->fanout) |
| goto out; |
| |
| if (type == PACKET_FANOUT_ROLLOVER || |
| (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) { |
| err = -ENOMEM; |
| rollover = kzalloc(sizeof(*rollover), GFP_KERNEL); |
| if (!rollover) |
| goto out; |
| atomic_long_set(&rollover->num, 0); |
| atomic_long_set(&rollover->num_huge, 0); |
| atomic_long_set(&rollover->num_failed, 0); |
| } |
| |
| if (type_flags & PACKET_FANOUT_FLAG_UNIQUEID) { |
| if (id != 0) { |
| err = -EINVAL; |
| goto out; |
| } |
| if (!fanout_find_new_id(sk, &id)) { |
| err = -ENOMEM; |
| goto out; |
| } |
| /* ephemeral flag for the first socket in the group: drop it */ |
| flags &= ~(PACKET_FANOUT_FLAG_UNIQUEID >> 8); |
| } |
| |
| match = NULL; |
| list_for_each_entry(f, &fanout_list, list) { |
| if (f->id == id && |
| read_pnet(&f->net) == sock_net(sk)) { |
| match = f; |
| break; |
| } |
| } |
| err = -EINVAL; |
| if (match) { |
| if (match->flags != flags) |
| goto out; |
| if (args->max_num_members && |
| args->max_num_members != match->max_num_members) |
| goto out; |
| } else { |
| if (args->max_num_members > PACKET_FANOUT_MAX) |
| goto out; |
| if (!args->max_num_members) |
| /* legacy PACKET_FANOUT_MAX */ |
| args->max_num_members = 256; |
| err = -ENOMEM; |
| match = kvzalloc(struct_size(match, arr, args->max_num_members), |
| GFP_KERNEL); |
| if (!match) |
| goto out; |
| write_pnet(&match->net, sock_net(sk)); |
| match->id = id; |
| match->type = type; |
| match->flags = flags; |
| INIT_LIST_HEAD(&match->list); |
| spin_lock_init(&match->lock); |
| refcount_set(&match->sk_ref, 0); |
| fanout_init_data(match); |
| match->prot_hook.type = po->prot_hook.type; |
| match->prot_hook.dev = po->prot_hook.dev; |
| match->prot_hook.func = packet_rcv_fanout; |
| match->prot_hook.af_packet_priv = match; |
| match->prot_hook.af_packet_net = read_pnet(&match->net); |
| match->prot_hook.id_match = match_fanout_group; |
| match->max_num_members = args->max_num_members; |
| list_add(&match->list, &fanout_list); |
| } |
| err = -EINVAL; |
| |
| spin_lock(&po->bind_lock); |
| if (po->running && |
| match->type == type && |
| match->prot_hook.type == po->prot_hook.type && |
| match->prot_hook.dev == po->prot_hook.dev) { |
| err = -ENOSPC; |
| if (refcount_read(&match->sk_ref) < match->max_num_members) { |
| __dev_remove_pack(&po->prot_hook); |
| |
| /* Paired with packet_setsockopt(PACKET_FANOUT_DATA) */ |
| WRITE_ONCE(po->fanout, match); |
| |
| po->rollover = rollover; |
| rollover = NULL; |
| refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1); |
| __fanout_link(sk, po); |
| err = 0; |
| } |
| } |
| spin_unlock(&po->bind_lock); |
| |
| if (err && !refcount_read(&match->sk_ref)) { |
| list_del(&match->list); |
| kvfree(match); |
| } |
| |
| out: |
| kfree(rollover); |
| mutex_unlock(&fanout_mutex); |
| return err; |
| } |
| |
| /* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes |
| * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout. |
| * It is the responsibility of the caller to call fanout_release_data() and |
| * free the returned packet_fanout (after synchronize_net()) |
| */ |
| static struct packet_fanout *fanout_release(struct sock *sk) |
| { |
| struct packet_sock *po = pkt_sk(sk); |
| struct packet_fanout *f; |
| |
| mutex_lock(&fanout_mutex); |
| f = po->fanout; |
| if (f) { |
| po->fanout = NULL; |
| |
| if (refcount_dec_and_test(&f->sk_ref)) |
| list_del(&f->list); |
| else |
| f = NULL; |
| } |
| mutex_unlock(&fanout_mutex); |
| |
| return f; |
| } |
| |
| static bool packet_extra_vlan_len_allowed(const struct net_device *dev, |
| struct sk_buff *skb) |
| { |
| /* Earlier code assumed this would be a VLAN pkt, double-check |
| * this now that we have the actual packet in hand. We can only |
| * do this check on Ethernet devices. |
| */ |
| if (unlikely(dev->type != ARPHRD_ETHER)) |
| return false; |
| |
| skb_reset_mac_header(skb); |
| return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q)); |
| } |
| |
| static const struct proto_ops packet_ops; |
| |
| static const struct proto_ops packet_ops_spkt; |
| |
| static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, |
| struct packet_type *pt, struct net_device *orig_dev) |
| { |
| struct sock *sk; |
| struct sockaddr_pkt *spkt; |
| |
| /* |
| * When we registered the protocol we saved the socket in the data |
| * field for just this event. |
| */ |
| |
| sk = pt->af_packet_priv; |
| |
| /* |
| * Yank back the headers [hope the device set this |
| * right or kerboom...] |
| * |
| * Incoming packets have ll header pulled, |
| * push it back. |
| * |
| * For outgoing ones skb->data == skb_mac_header(skb) |
| * so that this procedure is noop. |
| */ |
| |
| if (skb->pkt_type == PACKET_LOOPBACK) |
| goto out; |
| |
| if (!net_eq(dev_net(dev), sock_net(sk))) |
| goto out; |
| |
| skb = skb_share_check(skb, GFP_ATOMIC); |
| if (skb == NULL) |
| goto oom; |
| |
| /* drop any routing info */ |
| skb_dst_drop(skb); |
| |
| /* drop conntrack reference */ |
| nf_reset_ct(skb); |
| |
| spkt = &PACKET_SKB_CB(skb)->sa.pkt; |
| |
| skb_push(skb, skb->data - skb_mac_header(skb)); |
| |
| /* |
| * The SOCK_PACKET socket receives _all_ frames. |
| */ |
| |
| spkt->spkt_family = dev->type; |
| strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); |
| spkt->spkt_protocol = skb->protocol; |
| |
| /* |
| * Charge the memory to the socket. This is done specifically |
| * to prevent sockets using all the memory up. |
| */ |
| |
| if (sock_queue_rcv_skb(sk, skb) == 0) |
| return 0; |
| |
| out: |
| kfree_skb(skb); |
| oom: |
| return 0; |
| } |
| |
| static void packet_parse_headers(struct sk_buff *skb, struct socket *sock) |
| { |
| int depth; |
| |
| if ((!skb->protocol || skb->protocol == htons(ETH_P_ALL)) && |
| sock->type == SOCK_RAW) { |
| skb_reset_mac_header(skb); |
| skb->protocol = dev_parse_header_protocol(skb); |
| } |
| |
| /* Move network header to the right position for VLAN tagged packets */ |
| if (likely(skb->dev->type == ARPHRD_ETHER) && |
| eth_type_vlan(skb->protocol) && |
| vlan_get_protocol_and_depth(skb, skb->protocol, &depth) != 0) |
| skb_set_network_header(skb, depth); |
| |
| skb_probe_transport_header(skb); |
| } |
| |
| /* |
| * Output a raw packet to a device layer. This bypasses all the other |
| * protocol layers and you must therefore supply it with a complete frame |
| */ |
| |
| static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg, |
| size_t len) |
| { |
| struct sock *sk = sock->sk; |
| DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name); |
| struct sk_buff *skb = NULL; |
| struct net_device *dev; |
| struct sockcm_cookie sockc; |
| __be16 proto = 0; |
| int err; |
| int extra_len = 0; |
| |
| /* |
| * Get and verify the address. |
| */ |
| |
| if (saddr) { |
| if (msg->msg_namelen < sizeof(struct sockaddr)) |
| return -EINVAL; |
| if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) |
| proto = saddr->spkt_protocol; |
| } else |
| return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ |
| |
| /* |
| * Find the device first to size check it |
| */ |
| |
| saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0; |
| retry: |
| rcu_read_lock(); |
| dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); |
| err = -ENODEV; |
| if (dev == NULL) |
| goto out_unlock; |
| |
| err = -ENETDOWN; |
| if (!(dev->flags & IFF_UP)) |
| goto out_unlock; |
| |
| /* |
| * You may not queue a frame bigger than the mtu. This is the lowest level |
| * raw protocol and you must do your own fragmentation at this level. |
| */ |
| |
| if (unlikely(sock_flag(sk, SOCK_NOFCS))) { |
| if (!netif_supports_nofcs(dev)) { |
| err = -EPROTONOSUPPORT; |
| goto out_unlock; |
| } |
| extra_len = 4; /* We're doing our own CRC */ |
| } |
| |
| err = -EMSGSIZE; |
| if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len) |
| goto out_unlock; |
| |
| if (!skb) { |
| size_t reserved = LL_RESERVED_SPACE(dev); |
| int tlen = dev->needed_tailroom; |
| unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0; |
| |
| rcu_read_unlock(); |
| skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); |
| if (skb == NULL) |
| return -ENOBUFS; |
| /* FIXME: Save some space for broken drivers that write a hard |
| * header at transmission time by themselves. PPP is the notable |
| * one here. This should really be fixed at the driver level. |
| */ |
| skb_reserve(skb, reserved); |
| skb_reset_network_header(skb); |
| |
| /* Try to align data part correctly */ |
| if (hhlen) { |
| skb->data -= hhlen; |
| skb->tail -= hhlen; |
| if (len < hhlen) |
| skb_reset_network_header(skb); |
| } |
| err = memcpy_from_msg(skb_put(skb, len), msg, len); |
| if (err) |
| goto out_free; |
| goto retry; |
| } |
| |
| if (!dev_validate_header(dev, skb->data, len) || !skb->len) { |
| err = -EINVAL; |
| goto out_unlock; |
| } |
| if (len > (dev->mtu + dev->hard_header_len + extra_len) && |
| !packet_extra_vlan_len_allowed(dev, skb)) { |
| err = -EMSGSIZE; |
| goto out_unlock; |
| } |
| |
| sockcm_init(&sockc, sk); |
| if (msg->msg_controllen) { |
| err = sock_cmsg_send(sk, msg, &sockc); |
| if (unlikely(err)) |
| goto out_unlock; |
| } |
| |
| skb->protocol = proto; |
| skb->dev = dev; |
| skb->priority = sk->sk_priority; |
| skb->mark = sk->sk_mark; |
| skb->tstamp = sockc.transmit_time; |
| |
| skb_setup_tx_timestamp(skb, sockc.tsflags); |
| |
| if (unlikely(extra_len == 4)) |
| skb->no_fcs = 1; |
| |
| packet_parse_headers(skb, sock); |
| |
| dev_queue_xmit(skb); |
| rcu_read_unlock(); |
| return len; |
| |
| out_unlock: |
| rcu_read_unlock(); |
| out_free: |
| kfree_skb(skb); |
| return err; |
| } |
| |
| static unsigned int run_filter(struct sk_buff *skb, |
| const struct sock *sk, |
| unsigned int res) |
| { |
| struct sk_filter *filter; |
| |
| rcu_read_lock(); |
| filter = rcu_dereference(sk->sk_filter); |
| if (filter != NULL) |
| res = bpf_prog_run_clear_cb(filter->prog, skb); |
| rcu_read_unlock(); |
| |
| return res; |
| } |
| |
| static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb, |
| size_t *len) |
| { |
| struct virtio_net_hdr vnet_hdr; |
| |
| if (*len < sizeof(vnet_hdr)) |
| return -EINVAL; |
| *len -= sizeof(vnet_hdr); |
| |
| if (virtio_net_hdr_from_skb(skb, &vnet_hdr, vio_le(), true, 0)) |
| return -EINVAL; |
| |
| return memcpy_to_msg(msg, (void *)&vnet_hdr, sizeof(vnet_hdr)); |
| } |
| |
| /* |
| * This function makes lazy skb cloning in hope that most of packets |
| * are discarded by BPF. |
| * |
| * Note tricky part: we DO mangle shared skb! skb->data, skb->len |
| * and skb->cb are mangled. It works because (and until) packets |
| * falling here are owned by current CPU. Output packets are cloned |
| * by dev_queue_xmit_nit(), input packets are processed by net_bh |
| * sequentially, so that if we return skb to original state on exit, |
| * we will not harm anyone. |
| */ |
| |
| static int packet_rcv(struct sk_buff *skb, struct net_device *dev, |
| struct packet_type *pt, struct net_device *orig_dev) |
| { |
| struct sock *sk; |
| struct sockaddr_ll *sll; |
| struct packet_sock *po; |
| u8 *skb_head = skb->data; |
| int skb_len = skb->len; |
| unsigned int snaplen, res; |
| bool is_drop_n_account = false; |
| |
| if (skb->pkt_type == PACKET_LOOPBACK) |
| goto drop; |
| |
| sk = pt->af_packet_priv; |
| po = pkt_sk(sk); |
| |
| if (!net_eq(dev_net(dev), sock_net(sk))) |
| goto drop; |
| |
| skb->dev = dev; |
| |
| if (dev_has_header(dev)) { |
| /* The device has an explicit notion of ll header, |
| * exported to higher levels. |
| * |
| * Otherwise, the device hides details of its frame |
| * structure, so that corresponding packet head is |
| * never delivered to user. |
| */ |
| if (sk->sk_type != SOCK_DGRAM) |
| skb_push(skb, skb->data - skb_mac_header(skb)); |
| else if (skb->pkt_type == PACKET_OUTGOING) { |
| /* Special case: outgoing packets have ll header at head */ |
| skb_pull(skb, skb_network_offset(skb)); |
| } |
| } |
| |
| snaplen = skb->len; |
| |
| res = run_filter(skb, sk, snaplen); |
| if (!res) |
| goto drop_n_restore; |
| if (snaplen > res) |
| snaplen = res; |
| |
| if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) |
| goto drop_n_acct; |
| |
| if (skb_shared(skb)) { |
| struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); |
| if (nskb == NULL) |
| goto drop_n_acct; |
| |
| if (skb_head != skb->data) { |
| skb->data = skb_head; |
| skb->len = skb_len; |
| } |
| consume_skb(skb); |
| skb = nskb; |
| } |
| |
| sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8); |
| |
| sll = &PACKET_SKB_CB(skb)->sa.ll; |
| sll->sll_hatype = dev->type; |
| sll->sll_pkttype = skb->pkt_type; |
| if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV))) |
| sll->sll_ifindex = orig_dev->ifindex; |
| else |
| sll->sll_ifindex = dev->ifindex; |
| |
| sll->sll_halen = dev_parse_header(skb, sll->sll_addr); |
| |
| /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg(). |
| * Use their space for storing the original skb length. |
| */ |
| PACKET_SKB_CB(skb)->sa.origlen = skb->len; |
| |
| if (pskb_trim(skb, snaplen)) |
| goto drop_n_acct; |
| |
| skb_set_owner_r(skb, sk); |
| skb->dev = NULL; |
| skb_dst_drop(skb); |
| |
| /* drop conntrack reference */ |
| nf_reset_ct(skb); |
| |
| spin_lock(&sk->sk_receive_queue.lock); |
| po->stats.stats1.tp_packets++; |
| sock_skb_set_dropcount(sk, skb); |
| __skb_queue_tail(&sk->sk_receive_queue, skb); |
| spin_unlock(&sk->sk_receive_queue.lock); |
| sk->sk_data_ready(sk); |
| return 0; |
| |
| drop_n_acct: |
| is_drop_n_account = true; |
| atomic_inc(&po->tp_drops); |
| atomic_inc(&sk->sk_drops); |
| |
| drop_n_restore: |
| if (skb_head != skb->data && skb_shared(skb)) { |
| skb->data = skb_head; |
| skb->len = skb_len; |
| } |
| drop: |
| if (!is_drop_n_account) |
| consume_skb(skb); |
| else |
| kfree_skb(skb); |
| return 0; |
| } |
| |
| static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, |
| struct packet_type *pt, struct net_device *orig_dev) |
| { |
| struct sock *sk; |
| struct packet_sock *po; |
| struct sockaddr_ll *sll; |
| union tpacket_uhdr h; |
| u8 *skb_head = skb->data; |
| int skb_len = skb->len; |
| unsigned int snaplen, res; |
| unsigned long status = TP_STATUS_USER; |
| unsigned short macoff, hdrlen; |
| unsigned int netoff; |
| struct sk_buff *copy_skb = NULL; |
| struct timespec64 ts; |
| __u32 ts_status; |
| bool is_drop_n_account = false; |
| unsigned int slot_id = 0; |
| bool do_vnet = false; |
| |
| /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT. |
| * We may add members to them until current aligned size without forcing |
| * userspace to call getsockopt(..., PACKET_HDRLEN, ...). |
| */ |
| BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32); |
| BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48); |
| |
| if (skb->pkt_type == PACKET_LOOPBACK) |
| goto drop; |
| |
| sk = pt->af_packet_priv; |
| po = pkt_sk(sk); |
| |
| if (!net_eq(dev_net(dev), sock_net(sk))) |
| goto drop; |
| |
| if (dev_has_header(dev)) { |
| if (sk->sk_type != SOCK_DGRAM) |
| skb_push(skb, skb->data - skb_mac_header(skb)); |
| else if (skb->pkt_type == PACKET_OUTGOING) { |
| /* Special case: outgoing packets have ll header at head */ |
| skb_pull(skb, skb_network_offset(skb)); |
| } |
| } |
| |
| snaplen = skb->len; |
| |
| res = run_filter(skb, sk, snaplen); |
| if (!res) |
| goto drop_n_restore; |
| |
| /* If we are flooded, just give up */ |
| if (__packet_rcv_has_room(po, skb) == ROOM_NONE) { |
| atomic_inc(&po->tp_drops); |
| goto drop_n_restore; |
| } |
| |
| if (skb->ip_summed == CHECKSUM_PARTIAL) |
| status |= TP_STATUS_CSUMNOTREADY; |
| else if (skb->pkt_type != PACKET_OUTGOING && |
| skb_csum_unnecessary(skb)) |
| status |= TP_STATUS_CSUM_VALID; |
| |
| if (snaplen > res) |
| snaplen = res; |
| |
| if (sk->sk_type == SOCK_DGRAM) { |
| macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + |
| po->tp_reserve; |
| } else { |
| unsigned int maclen = skb_network_offset(skb); |
| netoff = TPACKET_ALIGN(po->tp_hdrlen + |
| (maclen < 16 ? 16 : maclen)) + |
| po->tp_reserve; |
| if (po->has_vnet_hdr) { |
| netoff += sizeof(struct virtio_net_hdr); |
| do_vnet = true; |
| } |
| macoff = netoff - maclen; |
| } |
| if (netoff > USHRT_MAX) { |
| atomic_inc(&po->tp_drops); |
| goto drop_n_restore; |
| } |
| if (po->tp_version <= TPACKET_V2) { |
| if (macoff + snaplen > po->rx_ring.frame_size) { |
| if (po->copy_thresh && |
| atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { |
| if (skb_shared(skb)) { |
| copy_skb = skb_clone(skb, GFP_ATOMIC); |
| } else { |
| copy_skb = skb_get(skb); |
| skb_head = skb->data; |
| } |
| if (copy_skb) { |
| memset(&PACKET_SKB_CB(copy_skb)->sa.ll, 0, |
| sizeof(PACKET_SKB_CB(copy_skb)->sa.ll)); |
| skb_set_owner_r(copy_skb, sk); |
| } |
| } |
| snaplen = po->rx_ring.frame_size - macoff; |
| if ((int)snaplen < 0) { |
| snaplen = 0; |
| do_vnet = false; |
| } |
| } |
| } else if (unlikely(macoff + snaplen > |
| GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) { |
| u32 nval; |
| |
| nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff; |
| pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n", |
| snaplen, nval, macoff); |
| snaplen = nval; |
| if (unlikely((int)snaplen < 0)) { |
| snaplen = 0; |
| macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len; |
| do_vnet = false; |
| } |
| } |
| spin_lock(&sk->sk_receive_queue.lock); |
| h.raw = packet_current_rx_frame(po, skb, |
| TP_STATUS_KERNEL, (macoff+snaplen)); |
| if (!h.raw) |
| goto drop_n_account; |
| |
| if (po->tp_version <= TPACKET_V2) { |
| slot_id = po->rx_ring.head; |
| if (test_bit(slot_id, po->rx_ring.rx_owner_map)) |
| goto drop_n_account; |
| __set_bit(slot_id, po->rx_ring.rx_owner_map); |
| } |
| |
| if (do_vnet && |
| virtio_net_hdr_from_skb(skb, h.raw + macoff - |
| sizeof(struct virtio_net_hdr), |
| vio_le(), true, 0)) { |
| if (po->tp_version == TPACKET_V3) |
| prb_clear_blk_fill_status(&po->rx_ring); |
| goto drop_n_account; |
| } |
| |
| if (po->tp_version <= TPACKET_V2) { |
| packet_increment_rx_head(po, &po->rx_ring); |
| /* |
| * LOSING will be reported till you read the stats, |
| * because it's COR - Clear On Read. |
| * Anyways, moving it for V1/V2 only as V3 doesn't need this |
| * at packet level. |
| */ |
| if (atomic_read(&po->tp_drops)) |
| status |= TP_STATUS_LOSING; |
| } |
| |
| po->stats.stats1.tp_packets++; |
| if (copy_skb) { |
| status |= TP_STATUS_COPY; |
| __skb_queue_tail(&sk->sk_receive_queue, copy_skb); |
| } |
| spin_unlock(&sk->sk_receive_queue.lock); |
| |
| skb_copy_bits(skb, 0, h.raw + macoff, snaplen); |
| |
| /* Always timestamp; prefer an existing software timestamp taken |
| * closer to the time of capture. |
| */ |
| ts_status = tpacket_get_timestamp(skb, &ts, |
| po->tp_tstamp | SOF_TIMESTAMPING_SOFTWARE); |
| if (!ts_status) |
| ktime_get_real_ts64(&ts); |
| |
| status |= ts_status; |
| |
| switch (po->tp_version) { |
| case TPACKET_V1: |
| h.h1->tp_len = skb->len; |
| h.h1->tp_snaplen = snaplen; |
| h.h1->tp_mac = macoff; |
| h.h1->tp_net = netoff; |
| h.h1->tp_sec = ts.tv_sec; |
| h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; |
| hdrlen = sizeof(*h.h1); |
| break; |
| case TPACKET_V2: |
| h.h2->tp_len = skb->len; |
| h.h2->tp_snaplen = snaplen; |
| h.h2->tp_mac = macoff; |
| h.h2->tp_net = netoff; |
| h.h2->tp_sec = ts.tv_sec; |
| h.h2->tp_nsec = ts.tv_nsec; |
| if (skb_vlan_tag_present(skb)) { |
| h.h2->tp_vlan_tci = skb_vlan_tag_get(skb); |
| h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto); |
| status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; |
| } else { |
| h.h2->tp_vlan_tci = 0; |
| h.h2->tp_vlan_tpid = 0; |
| } |
| memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding)); |
| hdrlen = sizeof(*h.h2); |
| break; |
| case TPACKET_V3: |
| /* tp_nxt_offset,vlan are already populated above. |
| * So DONT clear those fields here |
| */ |
| h.h3->tp_status |= status; |
| h.h3->tp_len = skb->len; |
| h.h3->tp_snaplen = snaplen; |
| h.h3->tp_mac = macoff; |
| h.h3->tp_net = netoff; |
| h.h3->tp_sec = ts.tv_sec; |
| h.h3->tp_nsec = ts.tv_nsec; |
| memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding)); |
| hdrlen = sizeof(*h.h3); |
| break; |
| default: |
| BUG(); |
| } |
| |
| sll = h.raw + TPACKET_ALIGN(hdrlen); |
| sll->sll_halen = dev_parse_header(skb, sll->sll_addr); |
| sll->sll_family = AF_PACKET; |
| sll->sll_hatype = dev->type; |
| sll->sll_protocol = skb->protocol; |
| sll->sll_pkttype = skb->pkt_type; |
| if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV))) |
| sll->sll_ifindex = orig_dev->ifindex; |
| else |
| sll->sll_ifindex = dev->ifindex; |
| |
| smp_mb(); |
| |
| #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 |
| if (po->tp_version <= TPACKET_V2) { |
| u8 *start, *end; |
| |
| end = (u8 *) PAGE_ALIGN((unsigned long) h.raw + |
| macoff + snaplen); |
| |
| for (start = h.raw; start < end; start += PAGE_SIZE) |
| flush_dcache_page(pgv_to_page(start)); |
| } |
| smp_wmb(); |
| #endif |
| |
| if (po->tp_version <= TPACKET_V2) { |
| spin_lock(&sk->sk_receive_queue.lock); |
| __packet_set_status(po, h.raw, status); |
| __clear_bit(slot_id, po->rx_ring.rx_owner_map); |
| spin_unlock(&sk->sk_receive_queue.lock); |
| sk->sk_data_ready(sk); |
| } else if (po->tp_version == TPACKET_V3) { |
| prb_clear_blk_fill_status(&po->rx_ring); |
| } |
| |
| drop_n_restore: |
| if (skb_head != skb->data && skb_shared(skb)) { |
| skb->data = skb_head; |
| skb->len = skb_len; |
| } |
| drop: |
| if (!is_drop_n_account) |
| consume_skb(skb); |
| else |
| kfree_skb(skb); |
| return 0; |
| |
| drop_n_account: |
| spin_unlock(&sk->sk_receive_queue.lock); |
| atomic_inc(&po->tp_drops); |
| is_drop_n_account = true; |
| |
| sk->sk_data_ready(sk); |
| kfree_skb(copy_skb); |
| goto drop_n_restore; |
| } |
| |
| static void tpacket_destruct_skb(struct sk_buff *skb) |
| { |
| struct packet_sock *po = pkt_sk(skb->sk); |
| |
| if (likely(po->tx_ring.pg_vec)) { |
| void *ph; |
| __u32 ts; |
| |
| ph = skb_zcopy_get_nouarg(skb); |
| packet_dec_pending(&po->tx_ring); |
| |
| ts = __packet_set_timestamp(po, ph, skb); |
| __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts); |
| |
| if (!packet_read_pending(&po->tx_ring)) |
| complete(&po->skb_completion); |
| } |
| |
| sock_wfree(skb); |
| } |
| |
| static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len) |
| { |
| if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && |
| (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + |
| __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 > |
| __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len))) |
| vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(), |
| __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + |
| __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2); |
| |
| if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len) |
| return -EINVAL; |
| |
| return 0; |
| } |
| |
| static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len, |
| struct virtio_net_hdr *vnet_hdr) |
| { |
| if (*len < sizeof(*vnet_hdr)) |
| return -EINVAL; |
| *len -= sizeof(*vnet_hdr); |
| |
| if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter)) |
| return -EFAULT; |
| |
| return __packet_snd_vnet_parse(vnet_hdr, *len); |
| } |
| |
| static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, |
| void *frame, struct net_device *dev, void *data, int tp_len, |
| __be16 proto, unsigned char *addr, int hlen, int copylen, |
| const struct sockcm_cookie *sockc) |
| { |
| union tpacket_uhdr ph; |
| int to_write, offset, len, nr_frags, len_max; |
| struct socket *sock = po->sk.sk_socket; |
| struct page *page; |
| int err; |
| |
| ph.raw = frame; |
| |
| skb->protocol = proto; |
| skb->dev = dev; |
| skb->priority = po->sk.sk_priority; |
| skb->mark = po->sk.sk_mark; |
| skb->tstamp = sockc->transmit_time; |
| skb_setup_tx_timestamp(skb, sockc->tsflags); |
| skb_zcopy_set_nouarg(skb, ph.raw); |
| |
| skb_reserve(skb, hlen); |
| skb_reset_network_header(skb); |
| |
| to_write = tp_len; |
| |
| if (sock->type == SOCK_DGRAM) { |
| err = dev_hard_header(skb, dev, ntohs(proto), addr, |
| NULL, tp_len); |
| if (unlikely(err < 0)) |
| return -EINVAL; |
| } else if (copylen) { |
| int hdrlen = min_t(int, copylen, tp_len); |
| |
| skb_push(skb, dev->hard_header_len); |
| skb_put(skb, copylen - dev->hard_header_len); |
| err = skb_store_bits(skb, 0, data, hdrlen); |
| if (unlikely(err)) |
| return err; |
| if (!dev_validate_header(dev, skb->data, hdrlen)) |
| return -EINVAL; |
| |
| data += hdrlen; |
| to_write -= hdrlen; |
| } |
| |
| offset = offset_in_page(data); |
| len_max = PAGE_SIZE - offset; |
| len = ((to_write > len_max) ? len_max : to_write); |
| |
| skb->data_len = to_write; |
| skb->len += to_write; |
| skb->truesize += to_write; |
| refcount_add(to_write, &po->sk.sk_wmem_alloc); |
| |
| while (likely(to_write)) { |
| nr_frags = skb_shinfo(skb)->nr_frags; |
| |
| if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { |
| pr_err("Packet exceed the number of skb frags(%lu)\n", |
| MAX_SKB_FRAGS); |
| return -EFAULT; |
| } |
| |
| page = pgv_to_page(data); |
| data += len; |
| flush_dcache_page(page); |
| get_page(page); |
| skb_fill_page_desc(skb, nr_frags, page, offset, len); |
| to_write -= len; |
| offset = 0; |
| len_max = PAGE_SIZE; |
| len = ((to_write > len_max) ? len_max : to_write); |
| } |
| |
| packet_parse_headers(skb, sock); |
| |
| return tp_len; |
| } |
| |
| static int tpacket_parse_header(struct packet_sock *po, void *frame, |
| int size_max, void **data) |
| { |
| union tpacket_uhdr ph; |
| int tp_len, off; |
| |
| ph.raw = frame; |
| |
| switch (po->tp_version) { |
| case TPACKET_V3: |
| if (ph.h3->tp_next_offset != 0) { |
| pr_warn_once("variable sized slot not supported"); |
| return -EINVAL; |
| } |
| tp_len = ph.h3->tp_len; |
| break; |
| case TPACKET_V2: |
| tp_len = ph.h2->tp_len; |
| break; |
| default: |
| tp_len = ph.h1->tp_len; |
| break; |
| } |
| if (unlikely(tp_len > size_max)) { |
| pr_err("packet size is too long (%d > %d)\n", tp_len, size_max); |
| return -EMSGSIZE; |
| } |
| |
| if (unlikely(po->tp_tx_has_off)) { |
| int off_min, off_max; |
| |
| off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll); |
| off_max = po->tx_ring.frame_size - tp_len; |
| if (po->sk.sk_type == SOCK_DGRAM) { |
| switch (po->tp_version) { |
| case TPACKET_V3: |
| off = ph.h3->tp_net; |
| break; |
| case TPACKET_V2: |
| off = ph.h2->tp_net; |
| break; |
| default: |
| off = ph.h1->tp_net; |
| break; |
| } |
| } else { |
| switch (po->tp_version) { |
| case TPACKET_V3: |
| off = ph.h3->tp_mac; |
| break; |
| case TPACKET_V2: |
| off = ph.h2->tp_mac; |
| break; |
| default: |
| off = ph.h1->tp_mac; |
| break; |
| } |
| } |
| if (unlikely((off < off_min) || (off_max < off))) |
| return -EINVAL; |
| } else { |
| off = po->tp_hdrlen - sizeof(struct sockaddr_ll); |
| } |
| |
| *data = frame + off; |
| return tp_len; |
| } |
| |
| static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) |
| { |
| struct sk_buff *skb = NULL; |
| struct net_device *dev; |
| struct virtio_net_hdr *vnet_hdr = NULL; |
| struct sockcm_cookie sockc; |
| __be16 proto; |
| int err, reserve = 0; |
| void *ph; |
| DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); |
| bool need_wait = !(msg->msg_flags & MSG_DONTWAIT); |
| unsigned char *addr = NULL; |
| int tp_len, size_max; |
| void *data; |
| int len_sum = 0; |
| int status = TP_STATUS_AVAILABLE; |
| int hlen, tlen, copylen = 0; |
| long timeo = 0; |
| |
| mutex_lock(&po->pg_vec_lock); |
| |
| /* packet_sendmsg() check on tx_ring.pg_vec was lockless, |
| * we need to confirm it under protection of pg_vec_lock. |
| */ |
| if (unlikely(!po->tx_ring.pg_vec)) { |
| err = -EBUSY; |
| goto out; |
| } |
| if (likely(saddr == NULL)) { |
| dev = packet_cached_dev_get(po); |
| proto = READ_ONCE(po->num); |
| } else { |
| err = -EINVAL; |
| if (msg->msg_namelen < sizeof(struct sockaddr_ll)) |
| goto out; |
| if (msg->msg_namelen < (saddr->sll_halen |
| + offsetof(struct sockaddr_ll, |
| sll_addr))) |
| goto out; |
| proto = saddr->sll_protocol; |
| dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); |
| if (po->sk.sk_socket->type == SOCK_DGRAM) { |
| if (dev && msg->msg_namelen < dev->addr_len + |
| offsetof(struct sockaddr_ll, sll_addr)) |
| goto out_put; |
| addr = saddr->sll_addr; |
| } |
| } |
| |
| err = -ENXIO; |
| if (unlikely(dev == NULL)) |
| goto out; |
| err = -ENETDOWN; |
| if (unlikely(!(dev->flags & IFF_UP))) |
| goto out_put; |
| |
| sockcm_init(&sockc, &po->sk); |
| if (msg->msg_controllen) { |
| err = sock_cmsg_send(&po->sk, msg, &sockc); |
| if (unlikely(err)) |
| goto out_put; |
| } |
| |
| if (po->sk.sk_socket->type == SOCK_RAW) |
| reserve = dev->hard_header_len; |
| size_max = po->tx_ring.frame_size |
| - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); |
| |
| if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !po->has_vnet_hdr) |
| size_max = dev->mtu + reserve + VLAN_HLEN; |
| |
| reinit_completion(&po->skb_completion); |
| |
| do { |
| ph = packet_current_frame(po, &po->tx_ring, |
| TP_STATUS_SEND_REQUEST); |
| if (unlikely(ph == NULL)) { |
| if (need_wait && skb) { |
| timeo = sock_sndtimeo(&po->sk, msg->msg_flags & MSG_DONTWAIT); |
| timeo = wait_for_completion_interruptible_timeout(&po->skb_completion, timeo); |
| if (timeo <= 0) { |
| err = !timeo ? -ETIMEDOUT : -ERESTARTSYS; |
| goto out_put; |
| } |
| } |
| /* check for additional frames */ |
| continue; |
| } |
| |
| skb = NULL; |
| tp_len = tpacket_parse_header(po, ph, size_max, &data); |
| if (tp_len < 0) |
| goto tpacket_error; |
| |
| status = TP_STATUS_SEND_REQUEST; |
| hlen = LL_RESERVED_SPACE(dev); |
| tlen = dev->needed_tailroom; |
| if (po->has_vnet_hdr) { |
| vnet_hdr = data; |
| data += sizeof(*vnet_hdr); |
| tp_len -= sizeof(*vnet_hdr); |
| if (tp_len < 0 || |
| __packet_snd_vnet_parse(vnet_hdr, tp_len)) { |
| tp_len = -EINVAL; |
| goto tpacket_error; |
| } |
| copylen = __virtio16_to_cpu(vio_le(), |
| vnet_hdr->hdr_len); |
| } |
| copylen = max_t(int, copylen, dev->hard_header_len); |
| skb = sock_alloc_send_skb(&po->sk, |
| hlen + tlen + sizeof(struct sockaddr_ll) + |
| (copylen - dev->hard_header_len), |
| !need_wait, &err); |
| |
| if (unlikely(skb == NULL)) { |
| /* we assume the socket was initially writeable ... */ |
| if (likely(len_sum > 0)) |
| err = len_sum; |
| goto out_status; |
| } |
| tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto, |
| addr, hlen, copylen, &sockc); |
| if (likely(tp_len >= 0) && |
| tp_len > dev->mtu + reserve && |
| !po->has_vnet_hdr && |
| !packet_extra_vlan_len_allowed(dev, skb)) |
| tp_len = -EMSGSIZE; |
| |
| if (unlikely(tp_len < 0)) { |
| tpacket_error: |
| if (po->tp_loss) { |
| __packet_set_status(po, ph, |
| TP_STATUS_AVAILABLE); |
| packet_increment_head(&po->tx_ring); |
| kfree_skb(skb); |
| continue; |
| } else { |
| status = TP_STATUS_WRONG_FORMAT; |
| err = tp_len; |
| goto out_status; |
| } |
| } |
| |
| if (po->has_vnet_hdr) { |
| if (virtio_net_hdr_to_skb(skb, vnet_hdr, vio_le())) { |
| tp_len = -EINVAL; |
| goto tpacket_error; |
| } |
| virtio_net_hdr_set_proto(skb, vnet_hdr); |
| } |
| |
| skb->destructor = tpacket_destruct_skb; |
| __packet_set_status(po, ph, TP_STATUS_SENDING); |
| packet_inc_pending(&po->tx_ring); |
| |
| status = TP_STATUS_SEND_REQUEST; |
| /* Paired with WRITE_ONCE() in packet_setsockopt() */ |
| err = READ_ONCE(po->xmit)(skb); |
| if (unlikely(err != 0)) { |
| if (err > 0) |
| err = net_xmit_errno(err); |
| if (err && __packet_get_status(po, ph) == |
| TP_STATUS_AVAILABLE) { |
| /* skb was destructed already */ |
| skb = NULL; |
| goto out_status; |
| } |
| /* |
| * skb was dropped but not destructed yet; |
| * let's treat it like congestion or err < 0 |
| */ |
| err = 0; |
| } |
| packet_increment_head(&po->tx_ring); |
| len_sum += tp_len; |
| } while (likely((ph != NULL) || |
| /* Note: packet_read_pending() might be slow if we have |
| * to call it as it's per_cpu variable, but in fast-path |
| * we already short-circuit the loop with the first |
| * condition, and luckily don't have to go that path |
| * anyway. |
| */ |
| (need_wait && packet_read_pending(&po->tx_ring)))); |
| |
| err = len_sum; |
| goto out_put; |
| |
| out_status: |
| __packet_set_status(po, ph, status); |
| kfree_skb(skb); |
| out_put: |
| dev_put(dev); |
| out: |
| mutex_unlock(&po->pg_vec_lock); |
| return err; |
| } |
| |
| static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, |
| size_t reserve, size_t len, |
| size_t linear, int noblock, |
| int *err) |
| { |
| struct sk_buff *skb; |
| |
| /* Under a page? Don't bother with paged skb. */ |
| if (prepad + len < PAGE_SIZE || !linear) |
| linear = len; |
| |
| skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, |
| err, 0); |
| if (!skb) |
| return NULL; |
| |
| skb_reserve(skb, reserve); |
| skb_put(skb, linear); |
| skb->data_len = len - linear; |
| skb->len += len - linear; |
| |
| return skb; |
| } |
| |
| static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) |
| { |
| struct sock *sk = sock->sk; |
| DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); |
| struct sk_buff *skb; |
| struct net_device *dev; |
| __be16 proto; |
| unsigned char *addr = NULL; |
| int err, reserve = 0; |
| struct sockcm_cookie sockc; |
| struct virtio_net_hdr vnet_hdr = { 0 }; |
| int offset = 0; |
| struct packet_sock *po = pkt_sk(sk); |
| bool has_vnet_hdr = false; |
| int hlen, tlen, linear; |
| int extra_len = 0; |
| |
| /* |
| * Get and verify the address. |
| */ |
| |
| if (likely(saddr == NULL)) { |
| dev = packet_cached_dev_get(po); |
| proto = READ_ONCE(po->num); |
| } else { |
| err = -EINVAL; |
| if (msg->msg_namelen < sizeof(struct sockaddr_ll)) |
| goto out; |
| if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) |
| goto out; |
| proto = saddr->sll_protocol; |
| dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); |
| if (sock->type == SOCK_DGRAM) { |
| if (dev && msg->msg_namelen < dev->addr_len + |
| offsetof(struct sockaddr_ll, sll_addr)) |
| goto out_unlock; |
| addr = saddr->sll_addr; |
| } |
| } |
| |
| err = -ENXIO; |
| if (unlikely(dev == NULL)) |
| goto out_unlock; |
| err = -ENETDOWN; |
| if (unlikely(!(dev->flags & IFF_UP))) |
| goto out_unlock; |
| |
| sockcm_init(&sockc, sk); |
| sockc.mark = sk->sk_mark; |
| if (msg->msg_controllen) { |
| err = sock_cmsg_send(sk, msg, &sockc); |
| if (unlikely(err)) |
| goto out_unlock; |
| } |
| |
| if (sock->type == SOCK_RAW) |
| reserve = dev->hard_header_len; |
| if (po->has_vnet_hdr) { |
| err = packet_snd_vnet_parse(msg, &len, &vnet_hdr); |
| if (err) |
| goto out_unlock; |
| has_vnet_hdr = true; |
| } |
| |
| if (unlikely(sock_flag(sk, SOCK_NOFCS))) { |
| if (!netif_supports_nofcs(dev)) { |
| err = -EPROTONOSUPPORT; |
| goto out_unlock; |
| } |
| extra_len = 4; /* We're doing our own CRC */ |
| } |
| |
| err = -EMSGSIZE; |
| if (!vnet_hdr.gso_type && |
| (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) |
| goto out_unlock; |
| |
| err = -ENOBUFS; |
| hlen = LL_RESERVED_SPACE(dev); |
| tlen = dev->needed_tailroom; |
| linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len); |
| linear = max(linear, min_t(int, len, dev->hard_header_len)); |
| skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear, |
| msg->msg_flags & MSG_DONTWAIT, &err); |
| if (skb == NULL) |
| goto out_unlock; |
| |
| skb_reset_network_header(skb); |
| |
| err = -EINVAL; |
| if (sock->type == SOCK_DGRAM) { |
| offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len); |
| if (unlikely(offset < 0)) |
| goto out_free; |
| } else if (reserve) { |
| skb_reserve(skb, -reserve); |
| if (len < reserve + sizeof(struct ipv6hdr) && |
| dev->min_header_len != dev->hard_header_len) |
| skb_reset_network_header(skb); |
| } |
| |
| /* Returns -EFAULT on error */ |
| err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len); |
| if (err) |
| goto out_free; |
| |
| if ((sock->type == SOCK_RAW && |
| !dev_validate_header(dev, skb->data, len)) || !skb->len) { |
| err = -EINVAL; |
| goto out_free; |
| } |
| |
| skb_setup_tx_timestamp(skb, sockc.tsflags); |
| |
| if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) && |
| !packet_extra_vlan_len_allowed(dev, skb)) { |
| err = -EMSGSIZE; |
| goto out_free; |
| } |
| |
| skb->protocol = proto; |
| skb->dev = dev; |
| skb->priority = sk->sk_priority; |
| skb->mark = sockc.mark; |
| skb->tstamp = sockc.transmit_time; |
| |
| if (unlikely(extra_len == 4)) |
| skb->no_fcs = 1; |
| |
| packet_parse_headers(skb, sock); |
| |
| if (has_vnet_hdr) { |
| err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le()); |
| if (err) |
| goto out_free; |
| len += sizeof(vnet_hdr); |
| virtio_net_hdr_set_proto(skb, &vnet_hdr); |
| } |
| |
| /* Paired with WRITE_ONCE() in packet_setsockopt() */ |
| err = READ_ONCE(po->xmit)(skb); |
| if (unlikely(err != 0)) { |
| if (err > 0) |
| err = net_xmit_errno(err); |
| if (err) |
| goto out_unlock; |
| } |
| |
| dev_put(dev); |
| |
| return len; |
| |
| out_free: |
| kfree_skb(skb); |
| out_unlock: |
| dev_put(dev); |
| out: |
| return err; |
| } |
| |
| static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) |
| { |
| struct sock *sk = sock->sk; |
| struct packet_sock *po = pkt_sk(sk); |
| |
| /* Reading tx_ring.pg_vec without holding pg_vec_lock is racy. |
| * tpacket_snd() will redo the check safely. |
| */ |
| if (data_race(po->tx_ring.pg_vec)) |
| return tpacket_snd(po, msg); |
| |
| return packet_snd(sock, msg, len); |
| } |
| |
| /* |
| * Close a PACKET socket. This is fairly simple. We immediately go |
| * to 'closed' state and remove our protocol entry in the device list. |
| */ |
| |
|