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iovisor / bcc

BCC - Tools for BPF-based Linux IO analysis, networking, monitoring, and more
Apache License 2.0
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sslniff not working on ubuntu-bionic-18.04-amd64 #2991

Open xxradar opened 4 years ago

xxradar commented 4 years ago

Hi everyone,

Very interested to get this working, but have some errors ... any way I can proceed ?

/virtual/main.c:27:17: warning: implicit declaration of function 'bpf_probe_read_user' is invalid in C99 [-Wimplicit-function-declaration]
                bpf_probe_read_user(&__data.v0, sizeof(__data.v0), buf);
                ^
/virtual/main.c:63:17: warning: implicit declaration of function 'bpf_probe_read_user' is invalid in C99 [-Wimplicit-function-declaration]
                bpf_probe_read_user(&__data.v0, sizeof(__data.v0), (char *)*bufp);
                ^
2 warnings generated.
LLVM ERROR: Program used external function 'bpf_probe_read_user' which could not be resolved!
sudo ./sslsniff
Traceback (most recent call last):
  File "./sslsniff", line 156, in <module>
    pid=args.pid or -1)
  File "/usr/lib/python2.7/dist-packages/bcc/__init__.py", line 1005, in attach_uprobe
    (path, addr) = BPF._check_path_symbol(name, sym, addr, pid)
  File "/usr/lib/python2.7/dist-packages/bcc/__init__.py", line 745, in _check_path_symbol
    raise Exception("could not determine address of symbol %s" % symname)
Exception: could not determine address of symbol PR_Write
yonghong-song commented 4 years ago

could you try latest bcc trunk? The issue can be workaround by adding

#define bpf_probe_read_user bpf_probe_read

What is your kernel version?

xxradar commented 4 years ago

$ uname -srm Linux 5.3.0-1023-aws x86_64

Also tried Linux 4.15.0-66-generic x86_64

yonghong-song commented 4 years ago

Could you paste the rewriter output here for 5.3 and 4.15?

diff --git a/tools/sslsniff.py b/tools/sslsniff.py
index 8c027fe3..0fe742a5 100755
--- a/tools/sslsniff.py
+++ b/tools/sslsniff.py
@@ -129,7 +129,7 @@ if args.debug or args.ebpf:
         exit()

-b = BPF(text=prog)
+b = BPF(text=prog, debug=4)

This will help check what is the problem?

kmille commented 3 years ago

I have the same problem on Debian 10 (4.19.0-13-cloud-amd64): EDIT: fixed by adding --no-nss as command line parameter

root@debian10-dev:/etc/postfix# sslsniff-bpfcc 
Running from kernel directory at: /lib/modules/4.19.0-13-cloud-amd64/source
clang -cc1 -triple x86_64-unknown-linux-gnu -emit-llvm-bc -emit-llvm-uselists -disable-free -disable-llvm-verifier -discard-value-names -main-file-name main.c -mrelocation-model static -mthread-model posix -fmath-errno -masm-verbose -mconstructor-aliases -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -coverage-notes-file /usr/src/linux-headers-4.19.0-13-common/main.gcno -nostdsysteminc -nobuiltininc -resource-dir lib/clang/7.0.1 -isystem /virtual/lib/clang/include -include ./include/linux/kconfig.h -include /virtual/include/bcc/bpf.h -include /virtual/include/bcc/helpers.h -isystem /virtual/include -I /etc/postfix -D __BPF_TRACING__ -I /lib/modules/4.19.0-13-cloud-amd64/build/arch/x86/include -I /lib/modules/4.19.0-13-cloud-amd64/build/arch/x86/include/generated/uapi -I /lib/modules/4.19.0-13-cloud-amd64/build/arch/x86/include/generated -I /lib/modules/4.19.0-13-cloud-amd64/build/include -I /lib/modules/4.19.0-13-cloud-amd64/build/./arch/x86/include/uapi -I /lib/modules/4.19.0-13-cloud-amd64/build/arch/x86/include/generated/uapi -I /lib/modules/4.19.0-13-cloud-amd64/build/include/uapi -I /lib/modules/4.19.0-13-cloud-amd64/build/include/generated -I /lib/modules/4.19.0-13-cloud-amd64/build/include/generated/uapi -I ./arch/x86/include -I arch/x86/include/generated/uapi -I arch/x86/include/generated -I include -I ./arch/x86/include/uapi -I arch/x86/include/generated/uapi -I ./include/uapi -I include/generated/uapi -D __KERNEL__ -D __HAVE_BUILTIN_BSWAP16__ -D __HAVE_BUILTIN_BSWAP32__ -D __HAVE_BUILTIN_BSWAP64__ -O2 -Wno-deprecated-declarations -Wno-gnu-variable-sized-type-not-at-end -Wno-pragma-once-outside-header -Wno-address-of-packed-member -Wno-unknown-warning-option -Wno-unused-value -Wno-pointer-sign -fdebug-compilation-dir /usr/src/linux-headers-4.19.0-13-common -ferror-limit 19 -fmessage-length 478 -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -o main.bc -x c /virtual/main.c -faddrsig
#if defined(BPF_LICENSE)
#error BPF_LICENSE cannot be specified through cflags
#endif
#if !defined(CONFIG_CC_STACKPROTECTOR)
#if defined(CONFIG_CC_STACKPROTECTOR_AUTO) \
    || defined(CONFIG_CC_STACKPROTECTOR_REGULAR) \
    || defined(CONFIG_CC_STACKPROTECTOR_STRONG)
#define CONFIG_CC_STACKPROTECTOR
#endif
#endif

#include <linux/ptrace.h>
#include <linux/sched.h>        /* For TASK_COMM_LEN */

struct probe_SSL_data_t {
        u64 timestamp_ns;
        u32 pid;
        char comm[TASK_COMM_LEN];
        char v0[464];
        u32 len;
};

BPF_PERF_OUTPUT(perf_SSL_write);

__attribute__((section(".bpf.fn.probe_SSL_write")))
int probe_SSL_write(struct pt_regs *ctx) {
 void *ssl = ctx->di; void *buf = ctx->si; int num = ctx->dx;
        u32 pid = bpf_get_current_pid_tgid();

        struct probe_SSL_data_t __data = {0};
        __data.timestamp_ns = bpf_ktime_get_ns();
        __data.pid = pid;
        __data.len = num;

        bpf_get_current_comm(&__data.comm, sizeof(__data.comm));

        if ( buf != 0) {
                bpf_probe_read(&__data.v0, sizeof(__data.v0), buf);
        }

        bpf_perf_event_output(ctx, bpf_pseudo_fd(1, 3), CUR_CPU_IDENTIFIER, &__data, sizeof(__data));
        return 0;
}

BPF_PERF_OUTPUT(perf_SSL_read);

BPF_HASH(bufs, u32, u64);

__attribute__((section(".bpf.fn.probe_SSL_read_enter")))
int probe_SSL_read_enter(struct pt_regs *ctx) {
 void *ssl = ctx->di; void *buf = ctx->si; int num = ctx->dx;
        u32 pid = bpf_get_current_pid_tgid();

        bpf_map_update_elem((void *)bpf_pseudo_fd(1, 5), &pid, (u64*)&buf, BPF_ANY);
        return 0;
}

__attribute__((section(".bpf.fn.probe_SSL_read_exit")))
int probe_SSL_read_exit(struct pt_regs *ctx) {
 void *ssl = ctx->di; void *buf = ctx->si; int num = ctx->dx;
        u32 pid = bpf_get_current_pid_tgid();

        u64 *bufp = bpf_map_lookup_elem((void *)bpf_pseudo_fd(1, 5), &pid);
        if (bufp == 0) {
                return 0;
        }

        struct probe_SSL_data_t __data = {0};
        __data.timestamp_ns = bpf_ktime_get_ns();
        __data.pid = pid;
        __data.len = PT_REGS_RC(ctx);

        bpf_get_current_comm(&__data.comm, sizeof(__data.comm));

        if (bufp != 0) {
                bpf_probe_read(&__data.v0, sizeof(__data.v0), (char *)*bufp);
        }

        bpf_map_delete_elem((void *)bpf_pseudo_fd(1, 5), &pid);

        bpf_perf_event_output(ctx, bpf_pseudo_fd(1, 4), CUR_CPU_IDENTIFIER, &__data, sizeof(__data));
        return 0;
}

#include <bcc/footer.h>
Traceback (most recent call last):
  File "/usr/sbin/sslsniff-bpfcc", line 158, in <module>
    pid=args.pid or -1)
  File "/usr/lib/python2.7/dist-packages/bcc/__init__.py", line 982, in attach_uprobe
    (path, addr) = BPF._check_path_symbol(name, sym, addr, pid)
  File "/usr/lib/python2.7/dist-packages/bcc/__init__.py", line 727, in _check_path_symbol
    raise Exception("could not determine address of symbol %s" % symname)
Exception: could not determine address of symbol PR_Write