tests/python/test_clang.py

#!/usr/bin/env python
# Copyright (c) PLUMgrid, Inc.
# Licensed under the Apache License, Version 2.0 (the "License")

from bcc import BPF
import ctypes as ct
from unittest import main, skipUnless, TestCase
import os
import sys
import socket
import struct
from contextlib import contextmanager
import distutils.version

@contextmanager
def redirect_stderr(to):
    stderr_fd = sys.stderr.fileno()
    with os.fdopen(os.dup(stderr_fd), 'wb') as copied, os.fdopen(to, 'w') as to:
        sys.stderr.flush()
        os.dup2(to.fileno(), stderr_fd)
        try:
            yield sys.stderr
        finally:
            sys.stderr.flush()
            os.dup2(copied.fileno(), stderr_fd)

def kernel_version_ge(major, minor):
    # True if running kernel is >= X.Y
    version = distutils.version.LooseVersion(os.uname()[2]).version
    if version[0] > major:
        return True
    if version[0] < major:
        return False
    if minor and version[1] < minor:
        return False
    return True

class TestClang(TestCase):
    def test_complex(self):
        b = BPF(src_file="test_clang_complex.c", debug=0)
        fn = b.load_func("handle_packet", BPF.SCHED_CLS)
    def test_printk(self):
        text = """
#include <bcc/proto.h>
int handle_packet(void *ctx) {
  u8 *cursor = 0;
  struct ethernet_t *ethernet = cursor_advance(cursor, sizeof(*ethernet));
  bpf_trace_printk("ethernet->dst = %llx, ethernet->src = %llx\\n",
                   ethernet->dst, ethernet->src);
  return 0;
}
"""
        b = BPF(text=text, debug=0)
        fn = b.load_func("handle_packet", BPF.SCHED_CLS)

    def test_probe_read1(self):
        text = """
#include <linux/sched.h>
#include <uapi/linux/ptrace.h>
int count_sched(struct pt_regs *ctx, struct task_struct *prev) {
    pid_t p = prev->pid;
    return (p != -1);
}
"""
        b = BPF(text=text, debug=0)
        fn = b.load_func("count_sched", BPF.KPROBE)

    def test_probe_read2(self):
        text = """
#include <linux/sched.h>
#include <uapi/linux/ptrace.h>
int count_foo(struct pt_regs *ctx, unsigned long a, unsigned long b) {
    return (a != b);
}
"""
        b = BPF(text=text, debug=0)
        fn = b.load_func("count_foo", BPF.KPROBE)

    def test_probe_read3(self):
        text = """
#define KBUILD_MODNAME "foo"
#include <net/tcp.h>
#define _(P) ({typeof(P) val = 0; bpf_probe_read(&val, sizeof(val), &P); val;})
int count_tcp(struct pt_regs *ctx, struct sk_buff *skb) {
    return _(TCP_SKB_CB(skb)->tcp_gso_size);
}
"""
        b = BPF(text=text)
        fn = b.load_func("count_tcp", BPF.KPROBE)

    def test_probe_read4(self):
        text = """
#define KBUILD_MODNAME "foo"
#include <net/tcp.h>
#define _(P) ({typeof(P) val = 0; bpf_probe_read(&val, sizeof(val), &P); val;})
int test(struct pt_regs *ctx, struct sk_buff *skb) {
    return _(TCP_SKB_CB(skb)->tcp_gso_size) + skb->protocol;
}
"""
        b = BPF(text=text)
        fn = b.load_func("test", BPF.KPROBE)

    def test_probe_read_whitelist1(self):
        text = """
#define KBUILD_MODNAME "foo"
#include <net/tcp.h>
int count_tcp(struct pt_regs *ctx, struct sk_buff *skb) {
    // The below define is in net/tcp.h:
    //    #define TCP_SKB_CB(__skb)	((struct tcp_skb_cb *)&((__skb)->cb[0]))
    // Note that it has AddrOf in the macro, which will cause current rewriter
    // failing below statement
    // return TCP_SKB_CB(skb)->tcp_gso_size;
    u16 val = 0;
    bpf_probe_read(&val, sizeof(val), &(TCP_SKB_CB(skb)->tcp_gso_size));
    return val;
}
"""
        b = BPF(text=text)
        fn = b.load_func("count_tcp", BPF.KPROBE)

    def test_probe_read_whitelist2(self):
        text = """
#define KBUILD_MODNAME "foo"
#include <net/tcp.h>
int count_tcp(struct pt_regs *ctx, struct sk_buff *skb) {
    // The below define is in net/tcp.h:
    //    #define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0]))
    // Note that it has AddrOf in the macro, which will cause current rewriter
    // failing below statement
    // return TCP_SKB_CB(skb)->tcp_gso_size;
    u16 val = 0;
    bpf_probe_read(&val, sizeof(val), &(TCP_SKB_CB(skb)->tcp_gso_size));
    return val + skb->protocol;
}
"""
        b = BPF(text=text)
        fn = b.load_func("count_tcp", BPF.KPROBE)

    def test_probe_read_keys(self):
        text = """
#include <uapi/linux/ptrace.h>
#include <linux/blkdev.h>
BPF_HASH(start, struct request *);
int do_request(struct pt_regs *ctx, struct request *req) {
    u64 ts = bpf_ktime_get_ns();
    start.update(&req, &ts);
    return 0;
}

int do_completion(struct pt_regs *ctx, struct request *req) {
    u64 *tsp = start.lookup(&req);
    if (tsp != 0) {
        start.delete(&req);
    }
    return 0;
}
"""
        b = BPF(text=text, debug=0)
        fns = b.load_funcs(BPF.KPROBE)

    def test_sscanf(self):
        text = """
BPF_HASH(stats, int, struct { u64 a; u64 b; u64 c:36; u64 d:28; struct { u32 a; u32 b; } s; }, 10);
int foo(void *ctx) {
    return 0;
}
"""
        b = BPF(text=text, debug=0)
        fn = b.load_func("foo", BPF.KPROBE)
        t = b.get_table("stats")
        s1 = t.key_sprintf(t.Key(2))
        self.assertEqual(s1, b"0x2")
        s2 = t.leaf_sprintf(t.Leaf(2, 3, 4, 1, (5, 6)))
        l = t.leaf_scanf(s2)
        self.assertEqual(l.a, 2)
        self.assertEqual(l.b, 3)
        self.assertEqual(l.c, 4)
        self.assertEqual(l.d, 1)
        self.assertEqual(l.s.a, 5)
        self.assertEqual(l.s.b, 6)

    def test_sscanf_array(self):
        text = """
BPF_HASH(stats, int, struct { u32 a[3]; u32 b; }, 10);
"""
        b = BPF(text=text, debug=0)
        t = b.get_table("stats")
        s1 = t.key_sprintf(t.Key(2))
        self.assertEqual(s1, b"0x2")
        s2 = t.leaf_sprintf(t.Leaf((ct.c_uint * 3)(1,2,3), 4))
        self.assertEqual(s2, b"{ [ 0x1 0x2 0x3 ] 0x4 }")
        l = t.leaf_scanf(s2)
        self.assertEqual(l.a[0], 1)
        self.assertEqual(l.a[1], 2)
        self.assertEqual(l.a[2], 3)
        self.assertEqual(l.b, 4)

    def test_sscanf_string(self):
        text = """
struct Symbol {
    char name[128];
    char path[128];
};
struct Event {
    uint32_t pid;
    uint32_t tid;
    struct Symbol stack[64];
};
BPF_TABLE("array", int, struct Event, comms, 1);
"""
        b = BPF(text=text)
        t = b.get_table("comms")
        s1 = t.leaf_sprintf(t[0])
        fill = b' { "" "" }' * 63
        self.assertEqual(s1, b'{ 0x0 0x0 [ { "" "" }%s ] }' % fill)
        l = t.Leaf(1, 2)
        name = b"libxyz"
        path = b"/usr/lib/libxyz.so"
        l.stack[0].name = name
        l.stack[0].path = path
        s2 = t.leaf_sprintf(l)
        self.assertEqual(s2,
                b'{ 0x1 0x2 [ { "%s" "%s" }%s ] }' % (name, path, fill))
        l = t.leaf_scanf(s2)
        self.assertEqual(l.pid, 1)
        self.assertEqual(l.tid, 2)
        self.assertEqual(l.stack[0].name, name)
        self.assertEqual(l.stack[0].path, path)

    def test_iosnoop(self):
        text = """
#include <linux/blkdev.h>
#include <uapi/linux/ptrace.h>

struct key_t {
    struct request *req;
};

BPF_HASH(start, struct key_t, u64, 1024);
int do_request(struct pt_regs *ctx, struct request *req) {
    struct key_t key = {};

    bpf_trace_printk("traced start %d\\n", req->__data_len);

    return 0;
}
"""
        b = BPF(text=text, debug=0)
        fn = b.load_func("do_request", BPF.KPROBE)

    def test_blk_start_request(self):
        text = """
#include <linux/blkdev.h>
#include <uapi/linux/ptrace.h>
int do_request(struct pt_regs *ctx, int req) {
    bpf_trace_printk("req ptr: 0x%x\\n", req);
    return 0;
}
"""
        b = BPF(text=text, debug=0)
        fn = b.load_func("do_request", BPF.KPROBE)

    def test_bpf_hash(self):
        text = """
BPF_HASH(table1);
BPF_HASH(table2, u32);
BPF_HASH(table3, u32, int);
"""
        b = BPF(text=text, debug=0)

    def test_consecutive_probe_read(self):
        text = """
#include <linux/fs.h>
#include <linux/mount.h>
BPF_HASH(table1, struct super_block *);
int trace_entry(struct pt_regs *ctx, struct file *file) {
    if (!file) return 0;
    struct vfsmount *mnt = file->f_path.mnt;
    if (mnt) {
        struct super_block *k = mnt->mnt_sb;
        u64 zero = 0;
        table1.update(&k, &zero);
        k = mnt->mnt_sb;
        table1.update(&k, &zero);
    }

    return 0;
}
"""
        b = BPF(text=text, debug=0)
        fn = b.load_func("trace_entry", BPF.KPROBE)

    def test_nested_probe_read(self):
        text = """
#include <linux/fs.h>
int trace_entry(struct pt_regs *ctx, struct file *file) {
    if (!file) return 0;
    const char *name = file->f_path.dentry->d_name.name;
    bpf_trace_printk("%s\\n", name);
    return 0;
}
"""
        b = BPF(text=text, debug=0)
        fn = b.load_func("trace_entry", BPF.KPROBE)

    def test_nested_probe_read_deref(self):
        text = """
#include <uapi/linux/ptrace.h>
struct sock {
    u32 *sk_daddr;
};
int test(struct pt_regs *ctx, struct sock *skp) {
    return *(skp->sk_daddr);
}
"""
        b = BPF(text=text)
        fn = b.load_func("test", BPF.KPROBE)

    def test_char_array_probe(self):
        BPF(text="""#include <linux/blkdev.h>
int kprobe__blk_update_request(struct pt_regs *ctx, struct request *req) {
    bpf_trace_printk("%s\\n", req->rq_disk->disk_name);
    return 0;
}""")

    def test_probe_read_helper(self):
        b = BPF(text="""
#include <linux/fs.h>
static void print_file_name(struct file *file) {
    if (!file) return;
    const char *name = file->f_path.dentry->d_name.name;
    bpf_trace_printk("%s\\n", name);
}
static void print_file_name2(int unused, struct file *file) {
    print_file_name(file);
}
int trace_entry1(struct pt_regs *ctx, struct file *file) {
    print_file_name(file);
    return 0;
}
int trace_entry2(struct pt_regs *ctx, int unused, struct file *file) {
    print_file_name2(unused, file);
    return 0;
}
""")
        fn = b.load_func("trace_entry1", BPF.KPROBE)
        fn = b.load_func("trace_entry2", BPF.KPROBE)

    def test_probe_unnamed_union_deref(self):
        text = """
#include <linux/mm_types.h>
int trace(struct pt_regs *ctx, struct page *page) {
    void *p = page->mapping;
    return p != NULL;
}
"""
        # depending on llvm, compile may pass/fail, but at least shouldn't crash
        try:
            b = BPF(text=text)
        except:
            pass

    def test_probe_struct_assign(self):
        b = BPF(text = """
#include <uapi/linux/ptrace.h>
struct args_t {
    const char *filename;
    int flags;
    int mode;
};
int do_sys_open(struct pt_regs *ctx, const char *filename,
        int flags, int mode) {
    struct args_t args = {};
    args.filename = filename;
    args.flags = flags;
    args.mode = mode;
    bpf_trace_printk("%s\\n", args.filename);
    return 0;
};
""")
        b.attach_kprobe(event=b.get_syscall_fnname("open"),
                        fn_name="do_sys_open")

    def test_task_switch(self):
        b = BPF(text="""
#include <uapi/linux/ptrace.h>
#include <linux/sched.h>
struct key_t {
  u32 prev_pid;
  u32 curr_pid;
};
BPF_HASH(stats, struct key_t, u64, 1024);
int kprobe__finish_task_switch(struct pt_regs *ctx, struct task_struct *prev) {
  struct key_t key = {};
  u64 zero = 0, *val;
  key.curr_pid = bpf_get_current_pid_tgid();
  key.prev_pid = prev->pid;

  val = stats.lookup_or_init(&key, &zero);
  (*val)++;
  return 0;
}
""")

    def test_probe_simple_assign(self):
        b = BPF(text="""
#include <uapi/linux/ptrace.h>
#include <linux/gfp.h>
struct leaf { size_t size; };
BPF_HASH(simple_map, u32, struct leaf);
int kprobe____kmalloc(struct pt_regs *ctx, size_t size) {
    u32 pid = bpf_get_current_pid_tgid();
    struct leaf* leaf = simple_map.lookup(&pid);
    if (leaf)
        leaf->size += size;
    return 0;
}""")

    def test_probe_simple_member_assign(self):
        b = BPF(text="""
#include <uapi/linux/ptrace.h>
#include <linux/netdevice.h>
struct leaf { void *ptr; };
int test(struct pt_regs *ctx, struct sk_buff *skb) {
    struct leaf l = {};
    struct leaf *lp = &l;
    lp->ptr = skb;
    return 0;
}""")
        b.load_func("test", BPF.KPROBE)

    def test_probe_member_expr_deref(self):
        b = BPF(text="""
#include <uapi/linux/ptrace.h>
#include <linux/netdevice.h>
struct leaf { struct sk_buff *ptr; };
int test(struct pt_regs *ctx, struct sk_buff *skb) {
    struct leaf l = {};
    struct leaf *lp = &l;
    lp->ptr = skb;
    return lp->ptr->priority;
}""")
        b.load_func("test", BPF.KPROBE)

    def test_probe_member_expr(self):
        b = BPF(text="""
#include <uapi/linux/ptrace.h>
#include <linux/netdevice.h>
struct leaf { struct sk_buff *ptr; };
int test(struct pt_regs *ctx, struct sk_buff *skb) {
    struct leaf l = {};
    struct leaf *lp = &l;
    lp->ptr = skb;
    return l.ptr->priority;
}""")
        b.load_func("test", BPF.KPROBE)

    def test_unop_probe_read(self):
        text = """
#include <linux/blkdev.h>
int trace_entry(struct pt_regs *ctx, struct request *req) {
    if (!(req->bio->bi_flags & 1))
        return 1;
    if (((req->bio->bi_flags)))
        return 1;
    return 0;
}
"""
        b = BPF(text=text)
        fn = b.load_func("trace_entry", BPF.KPROBE)

    def test_probe_read_nested_deref(self):
        text = """
#include <net/inet_sock.h>
int test(struct pt_regs *ctx, struct sock *sk) {
    struct sock *ptr1;
    struct sock **ptr2 = &ptr1;
    *ptr2 = sk;
    return ((struct sock *)(*ptr2))->sk_daddr;
}
"""
        b = BPF(text=text)
        fn = b.load_func("test", BPF.KPROBE)

    def test_probe_read_nested_deref2(self):
        text = """
#include <net/inet_sock.h>
int test(struct pt_regs *ctx, struct sock *sk) {
    struct sock *ptr1;
    struct sock **ptr2 = &ptr1;
    struct sock ***ptr3 = &ptr2;
    *ptr2 = sk;
    *ptr3 = ptr2;
    return ((struct sock *)(**ptr3))->sk_daddr;
}
"""
        b = BPF(text=text)
        fn = b.load_func("test", BPF.KPROBE)

    def test_probe_read_nested_deref_func(self):
        text = """
#include <net/inet_sock.h>
static int subtest(struct sock ***skp) {
    return ((struct sock *)(**skp))->sk_daddr;
}
int test(struct pt_regs *ctx, struct sock *sk) {
    struct sock *ptr1;
    struct sock **ptr2 = &ptr1;
    struct sock ***ptr3 = &ptr2;
    *ptr2 = sk;
    *ptr3 = ptr2;
    return subtest(ptr3);
}
"""
        b = BPF(text=text)
        fn = b.load_func("test", BPF.KPROBE)

    def test_probe_read_nested_member1(self):
        text = """
#include <net/inet_sock.h>
int test(struct pt_regs *ctx, struct sock *skp) {
    u32 *daddr = &skp->sk_daddr;
    return *daddr;
}
"""
        b = BPF(text=text)
        fn = b.load_func("test", BPF.KPROBE)

    def test_probe_read_nested_member2(self):
        text = """
#include <uapi/linux/ptrace.h>
struct sock {
    u32 **sk_daddr;
};
int test(struct pt_regs *ctx, struct sock *skp) {
    u32 *daddr = *(skp->sk_daddr);
    return *daddr;
}
"""
        b = BPF(text=text)
        fn = b.load_func("test", BPF.KPROBE)

    def test_probe_read_nested_member3(self):
        text = """
#include <uapi/linux/ptrace.h>
struct sock {
    u32 *sk_daddr;
};
int test(struct pt_regs *ctx, struct sock *skp) {
    return *(&skp->sk_daddr);
}
"""
        b = BPF(text=text)
        fn = b.load_func("test", BPF.KPROBE)

    def test_paren_probe_read(self):
        text = """
#include <net/inet_sock.h>
int trace_entry(struct pt_regs *ctx, struct sock *sk) {
    u16 sport = ((struct inet_sock *)sk)->inet_sport;
    return sport;
}
"""
        b = BPF(text=text)
        fn = b.load_func("trace_entry", BPF.KPROBE)

    def test_complex_leaf_types(self):
        text = """
struct list;
struct list {
  struct list *selfp;
  struct list *another_selfp;
  struct list *selfp_array[2];
};
struct empty {
};
union emptyu {
  struct empty *em1;
  struct empty em2;
  struct empty em3;
  struct empty em4;
};
BPF_ARRAY(t1, struct list, 1);
BPF_ARRAY(t2, struct list *, 1);
BPF_ARRAY(t3, union emptyu, 1);
"""
        b = BPF(text=text)
        self.assertEqual(ct.sizeof(b["t3"].Leaf), 8)

    def test_cflags(self):
        text = """
#ifndef MYFLAG
#error "MYFLAG not set as expected"
#endif
"""
        b = BPF(text=text, cflags=["-DMYFLAG"])

    def test_exported_maps(self):
        b1 = BPF(text="""BPF_TABLE_PUBLIC("hash", int, int, table1, 10);""")
        b2 = BPF(text="""BPF_TABLE("extern", int, int, table1, 10);""")
        t = b2["table1"]

    def test_syntax_error(self):
        with self.assertRaises(Exception):
            b = BPF(text="""int failure(void *ctx) { if (); return 0; }""")

    def test_nested_union(self):
        text = """
BPF_HASH(t1, struct bpf_tunnel_key, int, 1);
"""
        b = BPF(text=text)
        t1 = b["t1"]
        print(t1.Key().remote_ipv4)

    def test_too_many_args(self):
        text = """
#include <uapi/linux/ptrace.h>
int many(struct pt_regs *ctx, int a, int b, int c, int d, int e, int f, int g) {
    return 0;
}
"""
        with self.assertRaises(Exception):
            b = BPF(text=text)

    def test_call_macro_arg(self):
        text = """
BPF_PROG_ARRAY(jmp, 32);

#define JMP_IDX_PIPE (1U << 1)

enum action {
    ACTION_PASS
};

int process(struct xdp_md *ctx) {
    jmp.call((void *)ctx, ACTION_PASS);
    jmp.call((void *)ctx, JMP_IDX_PIPE);
    return XDP_PASS;
}
        """
        b = BPF(text=text)
        t = b["jmp"]
        self.assertEqual(len(t), 32);

    def test_update_macro_arg(self):
        text = """
BPF_ARRAY(act, u32, 32);

#define JMP_IDX_PIPE (1U << 1)

enum action {
    ACTION_PASS
};

int process(struct xdp_md *ctx) {
    act.increment(ACTION_PASS);
    act.increment(JMP_IDX_PIPE);
    return XDP_PASS;
}
        """
        b = BPF(text=text)
        t = b["act"]
        self.assertEqual(len(t), 32);

    def test_ext_ptr_maps1(self):
        bpf_text = """
#include <uapi/linux/ptrace.h>
#include <net/sock.h>
#include <bcc/proto.h>

BPF_HASH(currsock, u32, struct sock *);

int trace_entry(struct pt_regs *ctx, struct sock *sk,
    struct sockaddr *uaddr, int addr_len) {
    u32 pid = bpf_get_current_pid_tgid();
    currsock.update(&pid, &sk);
    return 0;
};

int trace_exit(struct pt_regs *ctx) {
    u32 pid = bpf_get_current_pid_tgid();
    struct sock **skpp;
    skpp = currsock.lookup(&pid);
    if (skpp) {
        struct sock *skp = *skpp;
        return skp->__sk_common.skc_dport;
    }
    return 0;
}
        """
        b = BPF(text=bpf_text)
        b.load_func("trace_entry", BPF.KPROBE)
        b.load_func("trace_exit", BPF.KPROBE)

    def test_ext_ptr_maps2(self):
        bpf_text = """
#include <uapi/linux/ptrace.h>
#include <net/sock.h>
#include <bcc/proto.h>

BPF_HASH(currsock, u32, struct sock *);

int trace_entry(struct pt_regs *ctx, struct sock *sk,
    struct sockaddr *uaddr, int addr_len) {
    u32 pid = bpf_get_current_pid_tgid();
    currsock.update(&pid, &sk);
    return 0;
};

int trace_exit(struct pt_regs *ctx) {
    u32 pid = bpf_get_current_pid_tgid();
    struct sock **skpp = currsock.lookup(&pid);
    if (skpp) {
        struct sock *skp = *skpp;
        return skp->__sk_common.skc_dport;
    }
    return 0;
}
        """
        b = BPF(text=bpf_text)
        b.load_func("trace_entry", BPF.KPROBE)
        b.load_func("trace_exit", BPF.KPROBE)

    def test_ext_ptr_maps_reverse(self):
        bpf_text = """
#include <uapi/linux/ptrace.h>
#include <net/sock.h>
#include <bcc/proto.h>

BPF_HASH(currsock, u32, struct sock *);

int trace_exit(struct pt_regs *ctx) {
    u32 pid = bpf_get_current_pid_tgid();
    struct sock **skpp;
    skpp = currsock.lookup(&pid);
    if (skpp) {
        struct sock *skp = *skpp;
        return skp->__sk_common.skc_dport;
    }
    return 0;
}

int trace_entry(struct pt_regs *ctx, struct sock *sk) {
    u32 pid = bpf_get_current_pid_tgid();
    currsock.update(&pid, &sk);
    return 0;
};
        """
        b = BPF(text=bpf_text)
        b.load_func("trace_entry", BPF.KPROBE)
        b.load_func("trace_exit", BPF.KPROBE)

    def test_ext_ptr_maps_indirect(self):
        bpf_text = """
#include <uapi/linux/ptrace.h>
#include <net/sock.h>
#include <bcc/proto.h>

BPF_HASH(currsock, u32, struct sock *);

int trace_entry(struct pt_regs *ctx, struct sock *sk) {
    u32 pid = bpf_get_current_pid_tgid();
    struct sock **skp = &sk;
    currsock.update(&pid, skp);
    return 0;
};

int trace_exit(struct pt_regs *ctx) {
    u32 pid = bpf_get_current_pid_tgid();
    struct sock **skpp;
    skpp = currsock.lookup(&pid);
    if (skpp) {
        struct sock *skp = *skpp;
        return skp->__sk_common.skc_dport;
    }
    return 0;
}
        """
        b = BPF(text=bpf_text)
        b.load_func("trace_entry", BPF.KPROBE)
        b.load_func("trace_exit", BPF.KPROBE)

    def test_bpf_dins_pkt_rewrite(self):
        text = """
#include <bcc/proto.h>
int dns_test(struct __sk_buff *skb) {
    u8 *cursor = 0;
    struct ethernet_t *ethernet = cursor_advance(cursor, sizeof(*ethernet));
    if(ethernet->type == ETH_P_IP) {
        struct ip_t *ip = cursor_advance(cursor, sizeof(*ip));
        ip->src = ip->dst;
        return 0;
    }
    return -1;
}
        """
        b = BPF(text=text)

    @skipUnless(kernel_version_ge(4,8), "requires kernel >= 4.8")
    def test_ext_ptr_from_helper(self):
        text = """
#include <linux/sched.h>
int test(struct pt_regs *ctx) {
    struct task_struct *task = (struct task_struct *)bpf_get_current_task();
    return task->prio;
}
"""
        b = BPF(text=text)
        fn = b.load_func("test", BPF.KPROBE)

    def test_unary_operator(self):
        text = """
#include <linux/fs.h>
#include <uapi/linux/ptrace.h>
int trace_read_entry(struct pt_regs *ctx, struct file *file) {
    return !file->f_op->read_iter;
}
        """
        b = BPF(text=text)
        b.attach_kprobe(event="__vfs_read", fn_name="trace_read_entry")

    def test_printk_f(self):
        text = """
#include <uapi/linux/ptrace.h>
int trace_entry(struct pt_regs *ctx) {
  bpf_trace_printk("%0.2f\\n", 1);
  return 0;
}
"""
        r, w = os.pipe()
        with redirect_stderr(to=w):
            BPF(text=text)
        r = os.fdopen(r)
        output = r.read()
        expectedWarn = "warning: only %d %u %x %ld %lu %lx %lld %llu %llx %p %s conversion specifiers allowed"
        self.assertIn(expectedWarn, output)
        r.close()

    def test_printk_lf(self):
        text = """
#include <uapi/linux/ptrace.h>
int trace_entry(struct pt_regs *ctx) {
  bpf_trace_printk("%lf\\n", 1);
  return 0;
}
"""
        r, w = os.pipe()
        with redirect_stderr(to=w):
            BPF(text=text)
        r = os.fdopen(r)
        output = r.read()
        expectedWarn = "warning: only %d %u %x %ld %lu %lx %lld %llu %llx %p %s conversion specifiers allowed"
        self.assertIn(expectedWarn, output)
        r.close()

    def test_printk_2s(self):
        text = """
#include <uapi/linux/ptrace.h>
int trace_entry(struct pt_regs *ctx) {
  char s1[] = "hello", s2[] = "world";
  bpf_trace_printk("%s %s\\n", s1, s2);
  return 0;
}
"""
        r, w = os.pipe()
        with redirect_stderr(to=w):
            BPF(text=text)
        r = os.fdopen(r)
        output = r.read()
        expectedWarn = "warning: cannot use several %s conversion specifiers"
        self.assertIn(expectedWarn, output)
        r.close()

    def test_map_insert(self):
        text = """
BPF_HASH(dummy);
void do_trace(struct pt_regs *ctx) {
    u64 key = 0, val = 2;
    dummy.insert(&key, &val);
    key = 1;
    dummy.update(&key, &val);
}
"""
        b = BPF(text=text)
        c_val = ct.c_ulong(1)
        b["dummy"][ct.c_ulong(0)] = c_val
        b["dummy"][ct.c_ulong(1)] = c_val
        b.attach_kprobe(event=b.get_syscall_fnname("sync"), fn_name="do_trace")
        libc = ct.CDLL("libc.so.6")
        libc.sync()
        self.assertEqual(1, b["dummy"][ct.c_ulong(0)].value)
        self.assertEqual(2, b["dummy"][ct.c_ulong(1)].value)

    def test_prog_array_delete(self):
        text = """
BPF_PROG_ARRAY(dummy, 256);
"""
        b1 = BPF(text=text)
        text = """
int do_next(struct pt_regs *ctx) {
    return 0;
}
"""
        b2 = BPF(text=text)
        fn = b2.load_func("do_next", BPF.KPROBE)
        c_key = ct.c_int(0)
        b1["dummy"][c_key] = ct.c_int(fn.fd)
        b1["dummy"].__delitem__(c_key);
        with self.assertRaises(KeyError):
            b1["dummy"][c_key]

    def test_invalid_noninline_call(self):
        text = """
int bar(void) {
    return 0;
}
int foo(struct pt_regs *ctx) {
    return bar();
}
"""
        with self.assertRaises(Exception):
            b = BPF(text=text)

    def test_incomplete_type(self):
        text = """
BPF_HASH(drops, struct key_t);
struct key_t {
    u64 location;
};
"""
        with self.assertRaises(Exception):
            b = BPF(text=text)

    def test_enumerations(self):
        text = """
enum b {
    CHOICE_A,
};
struct a {
    enum b test;
};
BPF_HASH(drops, struct a);
        """
        b = BPF(text=text)

    def test_int128_types(self):
        text = """
BPF_HASH(table1, unsigned __int128, __int128);
"""
        b = BPF(text=text)
        table = b['table1']
        self.assertEqual(ct.sizeof(table.Key), 16)
        self.assertEqual(ct.sizeof(table.Leaf), 16)
        table[
            table.Key.from_buffer_copy(
                socket.inet_pton(socket.AF_INET6, "2001:db8::"))
        ] = table.Leaf.from_buffer_copy(struct.pack('LL', 42, 123456789))
        for k, v in table.items():
            self.assertEqual(v[0], 42)
            self.assertEqual(v[1], 123456789)
            self.assertEqual(socket.inet_ntop(socket.AF_INET6,
                                              struct.pack('LL', k[0], k[1])),
                             "2001:db8::")

    def test_padding_types(self):
        text = """
struct key_t {
  u32 f1_1;               /* offset 0 */
  struct {
    char f2_1;            /* offset 16 */
    __int128 f2_2;        /* offset 32 */
  };
  u8 f1_3;                /* offset 48 */
  unsigned __int128 f1_4; /* offset 64 */
  char f1_5;              /* offset 80 */
};
struct value_t {
  u8 src[4] __attribute__ ((aligned (8))); /* offset 0 */
  u8 dst[4] __attribute__ ((aligned (8))); /* offset 8 */
};
BPF_HASH(table1, struct key_t, struct value_t);
"""
        b = BPF(text=text)
        table = b['table1']
        self.assertEqual(ct.sizeof(table.Key), 96)
        self.assertEqual(ct.sizeof(table.Leaf), 16)

    @skipUnless(kernel_version_ge(4,7), "requires kernel >= 4.7")
    def test_probe_read_tracepoint_context(self):
        text = """
#include <linux/netdevice.h>
TRACEPOINT_PROBE(skb, kfree_skb) {
    struct sk_buff *skb = (struct sk_buff *)args->skbaddr;
    return skb->protocol;
}
"""
        b = BPF(text=text)

    def test_probe_read_kprobe_ctx(self):
        text = """
#include <linux/sched.h>
#include <net/inet_sock.h>
int test(struct pt_regs *ctx) {
    struct sock *sk;
    sk = (struct sock *)PT_REGS_PARM1(ctx);
    return sk->sk_dport;
}
"""
        b = BPF(text=text)
        fn = b.load_func("test", BPF.KPROBE)

    def test_probe_read_ctx_array(self):
        text = """
#include <linux/sched.h>
#include <net/inet_sock.h>
int test(struct pt_regs *ctx) {
    struct sock *newsk = (struct sock *)PT_REGS_RC(ctx);
    return newsk->__sk_common.skc_rcv_saddr;
}
"""
        b = BPF(text=text)
        fn = b.load_func("test", BPF.KPROBE)

    @skipUnless(kernel_version_ge(4,7), "requires kernel >= 4.7")
    def test_probe_read_tc_ctx(self):
        text = """
#include <uapi/linux/pkt_cls.h>
#include <linux/if_ether.h>
int test(struct __sk_buff *ctx) {
    void* data_end = (void*)(long)ctx->data_end;
    void* data = (void*)(long)ctx->data;
    if (data + sizeof(struct ethhdr) > data_end)
        return TC_ACT_SHOT;
    struct ethhdr *eh = (struct ethhdr *)data;
    if (eh->h_proto == 0x1)
        return TC_ACT_SHOT;
    return TC_ACT_OK;
}
"""
        b = BPF(text=text)
        fn = b.load_func("test", BPF.SCHED_CLS)

    def test_probe_read_return(self):
        text = """
#define KBUILD_MODNAME "foo"
#include <uapi/linux/ptrace.h>
#include <linux/tcp.h>
static inline unsigned char *my_skb_transport_header(struct sk_buff *skb) {
    return skb->head + skb->transport_header;
}
int test(struct pt_regs *ctx, struct sock *sk, struct sk_buff *skb) {
    struct tcphdr *th = (struct tcphdr *)my_skb_transport_header(skb);
    return th->seq;
}
"""
        b = BPF(text=text)
        fn = b.load_func("test", BPF.KPROBE)

    def test_probe_read_multiple_return(self):
        text = """
#define KBUILD_MODNAME "foo"
#include <uapi/linux/ptrace.h>
#include <linux/tcp.h>
static inline u64 error_function() {
    return 0;
}
static inline unsigned char *my_skb_transport_header(struct sk_buff *skb) {
    if (skb)
        return skb->head + skb->transport_header;
    return (unsigned char *)error_function();
}
int test(struct pt_regs *ctx, struct sock *sk, struct sk_buff *skb) {
    struct tcphdr *th = (struct tcphdr *)my_skb_transport_header(skb);
    return th->seq;
}
"""
        b = BPF(text=text)
        fn = b.load_func("test", BPF.KPROBE)

    def test_probe_read_return_expr(self):
        text = """
#define KBUILD_MODNAME "foo"
#include <uapi/linux/ptrace.h>
#include <linux/tcp.h>
static inline unsigned char *my_skb_transport_header(struct sk_buff *skb) {
    return skb->head + skb->transport_header;
}
int test(struct pt_regs *ctx, struct sock *sk, struct sk_buff *skb) {
    u32 *seq = (u32 *)my_skb_transport_header(skb) + offsetof(struct tcphdr, seq);
    return *seq;
}
"""
        b = BPF(text=text)
        fn = b.load_func("test", BPF.KPROBE)

    def test_probe_read_return_call(self):
        text = """
#define KBUILD_MODNAME "foo"
#include <uapi/linux/ptrace.h>
#include <linux/tcp.h>
static inline struct tcphdr *my_skb_transport_header(struct sk_buff *skb) {
    return (struct tcphdr *)skb->head + skb->transport_header;
}
int test(struct pt_regs *ctx, struct sock *sk, struct sk_buff *skb) {
    return my_skb_transport_header(skb)->seq;
}
"""
        b = BPF(text=text)
        fn = b.load_func("test", BPF.KPROBE)

    def test_no_probe_read_addrof(self):
        text = """
#include <linux/sched.h>
#include <net/inet_sock.h>
static inline int test_help(__be16 *addr) {
    __be16 val = 0;
    bpf_probe_read(&val, sizeof(val), addr);
    return val;
}
int test(struct pt_regs *ctx) {
    struct sock *sk;
    sk = (struct sock *)PT_REGS_PARM1(ctx);
    return test_help(&sk->sk_dport);
}
"""
        b = BPF(text=text)
        fn = b.load_func("test", BPF.KPROBE)

    def test_probe_read_array_accesses1(self):
        text = """
#include <linux/ptrace.h>
#include <linux/dcache.h>
int test(struct pt_regs *ctx, const struct qstr *name) {
    return name->name[1];
}
"""
        b = BPF(text=text)
        fn = b.load_func("test", BPF.KPROBE)

    def test_probe_read_array_accesses2(self):
        text = """
#include <linux/ptrace.h>
#include <linux/dcache.h>
int test(struct pt_regs *ctx, const struct qstr *name) {
    return name->name  [ 1];
}
"""
        b = BPF(text=text)
        fn = b.load_func("test", BPF.KPROBE)

    def test_probe_read_array_accesses3(self):
        text = """
#include <linux/ptrace.h>
#include <linux/dcache.h>
int test(struct pt_regs *ctx, const struct qstr *name) {
    return (name->name)[1];
}
"""
        b = BPF(text=text)
        fn = b.load_func("test", BPF.KPROBE)

    def test_probe_read_array_accesses4(self):
        text = """
#include <linux/ptrace.h>
int test(struct pt_regs *ctx, char *name) {
    return name[1];
}
"""
        b = BPF(text=text)
        fn = b.load_func("test", BPF.KPROBE)

    def test_probe_read_array_accesses5(self):
        text = """
#include <linux/ptrace.h>
int test(struct pt_regs *ctx, char **name) {
    return (*name)[1];
}
"""
        b = BPF(text=text)
        fn = b.load_func("test", BPF.KPROBE)

    def test_probe_read_array_accesses6(self):
        text = """
#include <linux/ptrace.h>
struct test_t {
    int tab[5];
};
int test(struct pt_regs *ctx, struct test_t *t) {
    return *(&t->tab[1]);
}
"""
        b = BPF(text=text)
        fn = b.load_func("test", BPF.KPROBE)

    def test_probe_read_array_accesses7(self):
        text = """
#include <net/inet_sock.h>
int test(struct pt_regs *ctx, struct sock *sk) {
    return sk->__sk_common.skc_v6_rcv_saddr.in6_u.u6_addr32[0];
}
"""
        b = BPF(text=text)
        fn = b.load_func("test", BPF.KPROBE)

    def test_probe_read_array_accesses8(self):
        text = """
#include <linux/mm_types.h>
int test(struct pt_regs *ctx, struct mm_struct *mm) {
    return mm->rss_stat.count[MM_ANONPAGES].counter;
}
"""
        b = BPF(text=text)
        fn = b.load_func("test", BPF.KPROBE)

    def test_arbitrary_increment_simple(self):
        b = BPF(text=b"""
#include <uapi/linux/ptrace.h>
struct bpf_map;
BPF_HASH(map);
int map_delete(struct pt_regs *ctx, struct bpf_map *bpfmap, u64 *k) {
    map.increment(42, 10);
    return 0;
}
""")
        b.attach_kprobe(event=b"htab_map_delete_elem", fn_name=b"map_delete")
        b.cleanup()

    @skipUnless(kernel_version_ge(4,7), "requires kernel >= 4.7")
    def test_packed_structure(self):
        b = BPF(text=b"""
struct test {
    u16 a;
    u32 b;
} __packed;
BPF_TABLE("hash", u32, struct test, testing, 2);
TRACEPOINT_PROBE(kmem, kmalloc) {
    u32 key = 0;
    struct test info, *entry;
    entry = testing.lookup(&key);
    if (entry == NULL) {
        info.a = 10;
        info.b = 20;
        testing.update(&key, &info);
    }
    return 0;
}
""")
        if len(b["testing"].items()):
            st = b["testing"][ct.c_uint(0)]
            self.assertEqual(st.a, 10)
            self.assertEqual(st.b, 20)

if __name__ == "__main__":
    main()