| /* |
| * pcap-dag.c: Packet capture interface for Endace DAG card. |
| * |
| * The functionality of this code attempts to mimic that of pcap-linux as much |
| * as possible. This code is compiled in several different ways depending on |
| * whether DAG_ONLY and HAVE_DAG_API are defined. If HAVE_DAG_API is not |
| * defined it should not get compiled in, otherwise if DAG_ONLY is defined then |
| * the 'dag_' function calls are renamed to 'pcap_' equivalents. If DAG_ONLY |
| * is not defined then nothing is altered - the dag_ functions will be |
| * called as required from their pcap-linux/bpf equivalents. |
| * |
| * Author: Richard Littin, Sean Irvine ({richard,sean}@reeltwo.com) |
| * |
| * Modifications: |
| * 2003 May - Jesper Peterson <support@endace.com> |
| * Code shuffled around to suit fad-xxx.c structure |
| * Added atexit() handler to stop DAG if application is too lazy |
| * 2003 September - Koryn Grant <koryn@endace.com> |
| * Added support for nonblocking operation. |
| * Added support for processing more than a single packet in pcap_dispatch(). |
| * Fixed bug in loss counter code. |
| * Improved portability of loss counter code (e.g. use UINT_MAX instead of 0xffff). |
| * Removed unused local variables. |
| * Added required headers (ctype.h, limits.h, unistd.h, netinet/in.h). |
| * 2003 October - Koryn Grant <koryn@endace.com.> |
| * Changed semantics to match those of standard pcap on linux. |
| * - packets rejected by the filter are not counted. |
| */ |
| |
| #ifndef lint |
| static const char rcsid[] _U_ = |
| "@(#) $Header: /tcpdump/master/libpcap/pcap-dag.c,v 1.10.2.4 2003-11-21 10:20:45 guy Exp $ (LBL)"; |
| #endif |
| |
| #ifdef HAVE_CONFIG_H |
| #include "config.h" |
| #endif |
| |
| #include <sys/param.h> /* optionally get BSD define */ |
| |
| #include <stdlib.h> |
| #include <string.h> |
| #include <errno.h> |
| |
| #include "pcap-int.h" |
| |
| #include <ctype.h> |
| #include <netinet/in.h> |
| #include <sys/mman.h> |
| #include <sys/socket.h> |
| #include <sys/types.h> |
| #include <unistd.h> |
| |
| struct mbuf; /* Squelch compiler warnings on some platforms for */ |
| struct rtentry; /* declarations in <net/if.h> */ |
| #include <net/if.h> |
| |
| #include <dagnew.h> |
| #include <dagapi.h> |
| |
| #define MIN_DAG_SNAPLEN 12 |
| #define MAX_DAG_SNAPLEN 2040 |
| #define ATM_SNAPLEN 48 |
| |
| typedef struct pcap_dag_node { |
| struct pcap_dag_node *next; |
| pcap_t *p; |
| pid_t pid; |
| } pcap_dag_node_t; |
| |
| static pcap_dag_node_t *pcap_dags = NULL; |
| static int atexit_handler_installed = 0; |
| static const unsigned short endian_test_word = 0x0100; |
| |
| #define IS_BIGENDIAN() (*((unsigned char *)&endian_test_word)) |
| |
| /* |
| * Swap byte ordering of unsigned long long timestamp on a big endian |
| * machine. |
| */ |
| #define SWAP_TS(ull) ((ull & 0xff00000000000000LL) >> 56) | \ |
| ((ull & 0x00ff000000000000LL) >> 40) | \ |
| ((ull & 0x0000ff0000000000LL) >> 24) | \ |
| ((ull & 0x000000ff00000000LL) >> 8) | \ |
| ((ull & 0x00000000ff000000LL) << 8) | \ |
| ((ull & 0x0000000000ff0000LL) << 24) | \ |
| ((ull & 0x000000000000ff00LL) << 40) | \ |
| ((ull & 0x00000000000000ffLL) << 56) |
| |
| |
| #ifdef DAG_ONLY |
| /* This code is required when compiling for a DAG device only. */ |
| #include "pcap-dag.h" |
| |
| /* Replace dag function names with pcap equivalent. */ |
| #define dag_open_live pcap_open_live |
| #define dag_platform_finddevs pcap_platform_finddevs |
| #endif /* DAG_ONLY */ |
| |
| static int dag_setfilter(pcap_t *p, struct bpf_program *fp); |
| static int dag_stats(pcap_t *p, struct pcap_stat *ps); |
| static int dag_set_datalink(pcap_t *p, int dlt); |
| static int dag_get_datalink(pcap_t *p); |
| static int dag_setnonblock(pcap_t *p, int nonblock, char *errbuf); |
| |
| static void delete_pcap_dag(pcap_t *p) { |
| pcap_dag_node_t *curr = NULL, *prev = NULL; |
| |
| for (prev = NULL, curr = pcap_dags; |
| curr != NULL && curr->p != p; |
| prev = curr, curr = curr->next) { |
| /* empty */ |
| } |
| |
| if (curr != NULL && curr->p == p) { |
| if (prev != NULL) { |
| prev->next = curr->next; |
| } else { |
| pcap_dags = curr->next; |
| } |
| } |
| } |
| |
| /* |
| * Performs a graceful shutdown of the DAG card, frees dynamic memory held |
| * in the pcap_t structure, and closes the file descriptor for the DAG card. |
| */ |
| |
| static void dag_platform_close(pcap_t *p) { |
| |
| #ifdef linux |
| if (p != NULL && p->md.device != NULL) { |
| if(dag_stop(p->fd) < 0) |
| fprintf(stderr,"dag_stop %s: %s\n", p->md.device, strerror(errno)); |
| if(dag_close(p->fd) < 0) |
| fprintf(stderr,"dag_close %s: %s\n", p->md.device, strerror(errno)); |
| |
| free(p->md.device); |
| } |
| #else |
| if (p != NULL) { |
| if(dag_stop(p->fd) < 0) |
| fprintf(stderr,"dag_stop: %s\n", strerror(errno)); |
| if(dag_close(p->fd) < 0) |
| fprintf(stderr,"dag_close: %s\n", strerror(errno)); |
| } |
| #endif |
| delete_pcap_dag(p); |
| /* Note: don't need to call close(p->fd) here as dag_close(p->fd) does this. */ |
| } |
| |
| static void atexit_handler(void) { |
| while (pcap_dags != NULL) { |
| if (pcap_dags->pid == getpid()) { |
| dag_platform_close(pcap_dags->p); |
| } else { |
| delete_pcap_dag(pcap_dags->p); |
| } |
| } |
| } |
| |
| static int new_pcap_dag(pcap_t *p) { |
| pcap_dag_node_t *node = NULL; |
| |
| if ((node = malloc(sizeof(pcap_dag_node_t))) == NULL) { |
| return -1; |
| } |
| |
| if (!atexit_handler_installed) { |
| atexit(atexit_handler); |
| atexit_handler_installed = 1; |
| } |
| |
| node->next = pcap_dags; |
| node->p = p; |
| node->pid = getpid(); |
| |
| pcap_dags = node; |
| |
| return 0; |
| } |
| |
| /* |
| * Read at most max_packets from the capture stream and call the callback |
| * for each of them. Returns the number of packets handled, -1 if an |
| * error occured, or -2 if we were told to break out of the loop. |
| */ |
| static int dag_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user) { |
| unsigned int processed = 0; |
| int flags = p->md.dag_offset_flags; |
| unsigned int nonblocking = flags & DAGF_NONBLOCK; |
| |
| for (;;) |
| { |
| /* Get the next bufferful of packets (if necessary). */ |
| while (p->md.dag_mem_top - p->md.dag_mem_bottom < dag_record_size) { |
| |
| /* |
| * Has "pcap_breakloop()" been called? |
| */ |
| if (p->break_loop) { |
| /* |
| * Yes - clear the flag that indicates that |
| * it has, and return -2 to indicate that |
| * we were told to break out of the loop. |
| */ |
| p->break_loop = 0; |
| return -2; |
| } |
| |
| p->md.dag_mem_top = dag_offset(p->fd, &(p->md.dag_mem_bottom), flags); |
| if ((p->md.dag_mem_top - p->md.dag_mem_bottom < dag_record_size) && nonblocking) |
| { |
| /* Pcap is configured to process only available packets, and there aren't any. */ |
| return 0; |
| } |
| } |
| |
| /* Process the packets. */ |
| while (p->md.dag_mem_top - p->md.dag_mem_bottom >= dag_record_size) { |
| |
| unsigned short packet_len = 0; |
| int caplen = 0; |
| struct pcap_pkthdr pcap_header; |
| |
| dag_record_t *header = (dag_record_t *)(p->md.dag_mem_base + p->md.dag_mem_bottom); |
| u_char *dp = ((u_char *)header) + dag_record_size; |
| unsigned short rlen; |
| |
| /* |
| * Has "pcap_breakloop()" been called? |
| */ |
| if (p->break_loop) { |
| /* |
| * Yes - clear the flag that indicates that |
| * it has, and return -2 to indicate that |
| * we were told to break out of the loop. |
| */ |
| p->break_loop = 0; |
| return -2; |
| } |
| |
| if (IS_BIGENDIAN()) |
| { |
| rlen = header->rlen; |
| } |
| else |
| { |
| rlen = ntohs(header->rlen); |
| } |
| p->md.dag_mem_bottom += rlen; |
| |
| switch(header->type) { |
| case TYPE_ATM: |
| packet_len = ATM_SNAPLEN; |
| caplen = ATM_SNAPLEN; |
| dp += 4; |
| break; |
| |
| case TYPE_ETH: |
| if (IS_BIGENDIAN()) |
| { |
| packet_len = header->wlen; |
| } |
| else |
| { |
| packet_len = ntohs(header->wlen); |
| } |
| packet_len -= (p->md.dag_fcs_bits >> 3); |
| caplen = rlen - dag_record_size - 2; |
| if (caplen > packet_len) |
| { |
| caplen = packet_len; |
| } |
| dp += 2; |
| break; |
| |
| case TYPE_HDLC_POS: |
| if (IS_BIGENDIAN()) |
| { |
| packet_len = header->wlen; |
| } |
| else |
| { |
| packet_len = ntohs(header->wlen); |
| } |
| packet_len -= (p->md.dag_fcs_bits >> 3); |
| caplen = rlen - dag_record_size; |
| if (caplen > packet_len) |
| { |
| caplen = packet_len; |
| } |
| break; |
| } |
| |
| if (caplen > p->snapshot) |
| caplen = p->snapshot; |
| |
| /* Count lost packets. */ |
| if (header->lctr) { |
| if (p->md.stat.ps_drop > (UINT_MAX - header->lctr)) { |
| p->md.stat.ps_drop = UINT_MAX; |
| } else { |
| p->md.stat.ps_drop += header->lctr; |
| } |
| } |
| |
| /* Run the packet filter if there is one. */ |
| if ((p->fcode.bf_insns == NULL) || bpf_filter(p->fcode.bf_insns, dp, packet_len, caplen)) { |
| |
| /* convert between timestamp formats */ |
| register unsigned long long ts; |
| |
| if (IS_BIGENDIAN()) |
| { |
| ts = SWAP_TS(header->ts); |
| } |
| else |
| { |
| ts = header->ts; |
| } |
| |
| pcap_header.ts.tv_sec = ts >> 32; |
| ts = (ts & 0xffffffffULL) * 1000000; |
| ts += 0x80000000; /* rounding */ |
| pcap_header.ts.tv_usec = ts >> 32; |
| if (pcap_header.ts.tv_usec >= 1000000) { |
| pcap_header.ts.tv_usec -= 1000000; |
| pcap_header.ts.tv_sec++; |
| } |
| |
| /* Fill in our own header data */ |
| pcap_header.caplen = caplen; |
| pcap_header.len = packet_len; |
| |
| /* Count the packet. */ |
| p->md.stat.ps_recv++; |
| |
| /* Call the user supplied callback function */ |
| callback(user, &pcap_header, dp); |
| |
| /* Only count packets that pass the filter, for consistency with standard Linux behaviour. */ |
| processed++; |
| if (processed == cnt) |
| { |
| /* Reached the user-specified limit. */ |
| return cnt; |
| } |
| } |
| } |
| |
| if (nonblocking || processed) |
| { |
| return processed; |
| } |
| } |
| |
| return processed; |
| } |
| |
| /* |
| * Get a handle for a live capture from the given DAG device. Passing a NULL |
| * device will result in a failure. The promisc flag is ignored because DAG |
| * cards are always promiscuous. The to_ms parameter is also ignored as it is |
| * not supported in hardware. |
| * |
| * See also pcap(3). |
| */ |
| pcap_t *dag_open_live(const char *device, int snaplen, int promisc, int to_ms, char *ebuf) { |
| char conf[30]; /* dag configure string */ |
| pcap_t *handle; |
| char *s; |
| int n; |
| |
| if (device == NULL) { |
| snprintf(ebuf, PCAP_ERRBUF_SIZE, "device is NULL: %s", pcap_strerror(errno)); |
| return NULL; |
| } |
| /* Allocate a handle for this session. */ |
| |
| handle = malloc(sizeof(*handle)); |
| if (handle == NULL) { |
| snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc %s: %s", device, pcap_strerror(errno)); |
| return NULL; |
| } |
| |
| /* Initialize some components of the pcap structure. */ |
| |
| memset(handle, 0, sizeof(*handle)); |
| |
| if (strstr(device, "/dev") == NULL) { |
| char * newDev = (char *)malloc(strlen(device) + 6); |
| newDev[0] = '\0'; |
| strcat(newDev, "/dev/"); |
| strcat(newDev,device); |
| device = newDev; |
| } else { |
| device = strdup(device); |
| } |
| |
| if (device == NULL) { |
| snprintf(ebuf, PCAP_ERRBUF_SIZE, "str_dup: %s\n", pcap_strerror(errno)); |
| goto fail; |
| } |
| |
| /* setup device parameters */ |
| if((handle->fd = dag_open((char *)device)) < 0) { |
| snprintf(ebuf, PCAP_ERRBUF_SIZE, "dag_open %s: %s", device, pcap_strerror(errno)); |
| goto fail; |
| } |
| |
| /* set the card snap length to the specified snaplen parameter */ |
| if (snaplen == 0 || snaplen > MAX_DAG_SNAPLEN) { |
| snaplen = MAX_DAG_SNAPLEN; |
| } else if (snaplen < MIN_DAG_SNAPLEN) { |
| snaplen = MIN_DAG_SNAPLEN; |
| } |
| /* snap len has to be a multiple of 4 */ |
| snprintf(conf, 30, "varlen slen=%d", (snaplen + 3) & ~3); |
| |
| fprintf(stderr, "Configuring DAG with '%s'.\n", conf); |
| if(dag_configure(handle->fd, conf) < 0) { |
| snprintf(ebuf, PCAP_ERRBUF_SIZE,"dag_configure %s: %s\n", device, pcap_strerror(errno)); |
| goto fail; |
| } |
| |
| if((handle->md.dag_mem_base = dag_mmap(handle->fd)) == MAP_FAILED) { |
| snprintf(ebuf, PCAP_ERRBUF_SIZE,"dag_mmap %s: %s\n", device, pcap_strerror(errno)); |
| goto fail; |
| } |
| |
| if(dag_start(handle->fd) < 0) { |
| snprintf(ebuf, PCAP_ERRBUF_SIZE, "dag_start %s: %s\n", device, pcap_strerror(errno)); |
| goto fail; |
| } |
| |
| /* |
| * Important! You have to ensure bottom is properly |
| * initialized to zero on startup, it won't give you |
| * a compiler warning if you make this mistake! |
| */ |
| handle->md.dag_mem_bottom = 0; |
| handle->md.dag_mem_top = 0; |
| |
| /* TODO: query the card */ |
| handle->md.dag_fcs_bits = 32; |
| if ((s = getenv("ERF_FCS_BITS")) != NULL) { |
| if ((n = atoi(s)) == 0 || n == 16|| n == 32) { |
| handle->md.dag_fcs_bits = n; |
| } else { |
| snprintf(ebuf, PCAP_ERRBUF_SIZE, |
| "pcap_open_live %s: bad ERF_FCS_BITS value (%d) in environment\n", device, n); |
| goto fail; |
| } |
| } |
| |
| handle->snapshot = snaplen; |
| /*handle->md.timeout = to_ms; */ |
| |
| if ((handle->linktype = dag_get_datalink(handle)) < 0) { |
| snprintf(ebuf, PCAP_ERRBUF_SIZE, "dag_get_linktype %s: unknown linktype\n", device); |
| goto fail; |
| } |
| |
| handle->bufsize = 0; |
| |
| if (new_pcap_dag(handle) < 0) { |
| snprintf(ebuf, PCAP_ERRBUF_SIZE, "new_pcap_dag %s: %s\n", device, pcap_strerror(errno)); |
| goto fail; |
| } |
| |
| /* |
| * "select()" and "poll()" don't (yet) work on DAG device descriptors. |
| */ |
| handle->selectable_fd = -1; |
| |
| #ifdef linux |
| handle->md.device = (char *)device; |
| #else |
| free((char *)device); |
| device = NULL; |
| #endif |
| |
| handle->read_op = dag_read; |
| handle->setfilter_op = dag_setfilter; |
| handle->set_datalink_op = dag_set_datalink; |
| handle->getnonblock_op = pcap_getnonblock_fd; |
| handle->setnonblock_op = dag_setnonblock; |
| handle->stats_op = dag_stats; |
| handle->close_op = dag_platform_close; |
| |
| return handle; |
| |
| fail: |
| if (device != NULL) { |
| free((char *)device); |
| } |
| if (handle != NULL) { |
| free(handle); |
| } |
| |
| return NULL; |
| } |
| |
| static int dag_stats(pcap_t *p, struct pcap_stat *ps) { |
| /* This needs to be filled out correctly. Hopefully a dagapi call will |
| provide all necessary information. |
| */ |
| /*p->md.stat.ps_recv = 0;*/ |
| /*p->md.stat.ps_drop = 0;*/ |
| |
| *ps = p->md.stat; |
| |
| return 0; |
| } |
| |
| /* |
| * Get from "/proc/dag" all interfaces listed there; if they're |
| * already in the list of interfaces we have, that won't add another |
| * instance, but if they're not, that'll add them. |
| * |
| * We don't bother getting any addresses for them. |
| * |
| * We also don't fail if we couldn't open "/proc/dag"; we just leave |
| * the list of interfaces as is. |
| */ |
| int |
| dag_platform_finddevs(pcap_if_t **devlistp, char *errbuf) |
| { |
| FILE *proc_dag_f; |
| char linebuf[512]; |
| int linenum; |
| unsigned char *p; |
| char name[512]; /* XXX - pick a size */ |
| char *q; |
| int ret = 0; |
| |
| /* Quick exit if /proc/dag not readable */ |
| proc_dag_f = fopen("/proc/dag", "r"); |
| if (proc_dag_f == NULL) |
| { |
| int i; |
| char dev[16] = "dagx"; |
| |
| for (i = '0'; ret == 0 && i <= '9'; i++) { |
| dev[3] = i; |
| if (pcap_add_if(devlistp, dev, 0, NULL, errbuf) == -1) { |
| /* |
| * Failure. |
| */ |
| ret = -1; |
| } |
| } |
| |
| return (ret); |
| } |
| |
| for (linenum = 1; |
| fgets(linebuf, sizeof linebuf, proc_dag_f) != NULL; linenum++) { |
| |
| /* |
| * Skip the first two lines - they're headers. |
| */ |
| if (linenum <= 2) |
| continue; |
| |
| p = &linebuf[0]; |
| |
| if (*p == '\0' || *p == '\n' || *p != 'D') |
| continue; /* not a Dag line */ |
| |
| /* |
| * Get the interface name. |
| */ |
| q = &name[0]; |
| while (*p != '\0' && *p != ':') { |
| if (*p != ' ') |
| *q++ = tolower(*p++); |
| else |
| p++; |
| } |
| *q = '\0'; |
| |
| /* |
| * Add an entry for this interface, with no addresses. |
| */ |
| p[strlen(p) - 1] = '\0'; /* get rid of \n */ |
| if (pcap_add_if(devlistp, name, 0, strdup(p + 2), errbuf) == -1) { |
| /* |
| * Failure. |
| */ |
| ret = -1; |
| break; |
| } |
| } |
| if (ret != -1) { |
| /* |
| * Well, we didn't fail for any other reason; did we |
| * fail due to an error reading the file? |
| */ |
| if (ferror(proc_dag_f)) { |
| (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| "Error reading /proc/dag: %s", |
| pcap_strerror(errno)); |
| ret = -1; |
| } |
| } |
| |
| (void)fclose(proc_dag_f); |
| return (ret); |
| } |
| |
| /* |
| * Installs the given bpf filter program in the given pcap structure. There is |
| * no attempt to store the filter in kernel memory as that is not supported |
| * with DAG cards. |
| */ |
| static int dag_setfilter(pcap_t *p, struct bpf_program *fp) { |
| if (!p) |
| return -1; |
| if (!fp) { |
| strncpy(p->errbuf, "setfilter: No filter specified", |
| sizeof(p->errbuf)); |
| return -1; |
| } |
| |
| /* Make our private copy of the filter */ |
| |
| if (install_bpf_program(p, fp) < 0) { |
| snprintf(p->errbuf, sizeof(p->errbuf), |
| "malloc: %s", pcap_strerror(errno)); |
| return -1; |
| } |
| |
| p->md.use_bpf = 0; |
| |
| return (0); |
| } |
| |
| static int |
| dag_set_datalink(pcap_t *p, int dlt) |
| { |
| return (0); |
| } |
| |
| static int |
| dag_setnonblock(pcap_t *p, int nonblock, char *errbuf) |
| { |
| /* |
| * Set non-blocking mode on the FD. |
| * XXX - is that necessary? If not, don't bother calling it, |
| * and have a "dag_getnonblock()" function that looks at |
| * "p->md.dag_offset_flags". |
| */ |
| if (pcap_setnonblock_fd(p, nonblock, errbuf) < 0) |
| return (-1); |
| |
| if (nonblock) { |
| p->md.dag_offset_flags |= DAGF_NONBLOCK; |
| } else { |
| p->md.dag_offset_flags &= ~DAGF_NONBLOCK; |
| } |
| return (0); |
| } |
| |
| static int |
| dag_get_datalink(pcap_t *p) |
| { |
| int linktype = -1; |
| |
| /* Check the type through a dagapi call. |
| */ |
| switch(dag_linktype(p->fd)) { |
| case TYPE_HDLC_POS: { |
| dag_record_t *record; |
| |
| /* peek at the first available record to see if it is PPP */ |
| while ((p->md.dag_mem_top - p->md.dag_mem_bottom) < (dag_record_size + 4)) { |
| p->md.dag_mem_top = dag_offset(p->fd, &(p->md.dag_mem_bottom), 0); |
| } |
| record = (dag_record_t *)(p->md.dag_mem_base + p->md.dag_mem_bottom); |
| |
| if ((ntohl(record->rec.pos.hdlc) & 0xffff0000) == 0xff030000) { |
| linktype = DLT_PPP_SERIAL; |
| fprintf(stderr, "Set DAG linktype to %d (DLT_PPP_SERIAL)\n", linktype); |
| } else { |
| linktype = DLT_CHDLC; |
| fprintf(stderr, "Set DAG linktype to %d (DLT_CHDLC)\n", linktype); |
| } |
| break; |
| } |
| case TYPE_ETH: |
| linktype = DLT_EN10MB; |
| fprintf(stderr, "Set DAG linktype to %d (DLT_EN10MB)\n", linktype); |
| break; |
| case TYPE_ATM: |
| linktype = DLT_ATM_RFC1483; |
| fprintf(stderr, "Set DAG linktype to %d (DLT_ATM_RFC1483)\n", linktype); |
| break; |
| case TYPE_LEGACY: |
| linktype = DLT_NULL; |
| fprintf(stderr, "Set DAG linktype to %d (DLT_NULL)\n", linktype); |
| break; |
| default: |
| fprintf(stderr, "Unknown DAG linktype %d\n", dag_linktype(p->fd)); |
| break; |
| } |
| |
| return linktype; |
| } |