tc: {m, f}_ebpf: add option for dumping verifier log

Currently, only on error we get a log dump, but I found it useful when
working with eBPF to have an option to also dump the log on success.
Also spotted a typo in a header comment, which is fixed here as well.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>

diff --git a/tc/f_bpf.c b/tc/f_bpf.c
index 11d6db0cab7ef16be7b92c32f6d245d37e489653..597ef60622d9bc8847eadc29d31949fc0e447788 100644 (file)
--- a/tc/f_bpf.c
+++ b/tc/f_bpf.c
@@ -40,7 +40,8 @@ static void explain(void)
        fprintf(stderr, " bytecode-file FILE\n");
        fprintf(stderr, "\n");
        fprintf(stderr, "eBPF use case:\n");
-       fprintf(stderr, " object-file FILE [ section CLS_NAME ] [ export UDS_FILE ]\n");
+       fprintf(stderr, " object-file FILE [ section CLS_NAME ] [ export UDS_FILE ]");
+       fprintf(stderr, " [ verbose ]\n");
        fprintf(stderr, "\n");
        fprintf(stderr, "Common remaining options:\n");
        fprintf(stderr, " [ action ACTION_SPEC ]\n");
@@ -94,12 +95,13 @@ static int bpf_parse_opt(struct filter_util *qu, char *handle,
        while (argc > 0) {
                if (matches(*argv, "run") == 0) {
                        struct sock_filter bpf_ops[BPF_MAXINSNS];
-                       bool from_file, ebpf;
+                       bool from_file, ebpf, bpf_verbose;
                        int ret;
 
                        NEXT_ARG();
 opt_bpf:
                        bpf_sec_name = bpf_default_section(bpf_type);
+                       bpf_verbose = false;
                        ebpf = false;
                        seen_run = true;
 
@@ -135,11 +137,17 @@ opt_bpf:
                                        bpf_uds_name = *argv;
                                        NEXT_ARG();
                                }
+                               if (strcmp(*argv, "verbose") == 0 ||
+                                   strcmp(*argv, "verb") == 0) {
+                                       bpf_verbose = true;
+                                       NEXT_ARG();
+                               }
 
                                PREV_ARG();
                        }
 
-                       ret = ebpf ? bpf_open_object(bpf_obj, bpf_type, bpf_sec_name) :
+                       ret = ebpf ? bpf_open_object(bpf_obj, bpf_type, bpf_sec_name,
+                                                    bpf_verbose) :
                                     bpf_parse_ops(argc, argv, bpf_ops, from_file);
                        if (ret < 0) {
                                fprintf(stderr, "%s\n", ebpf ?

diff --git a/tc/m_bpf.c b/tc/m_bpf.c
index 16468f264d9c0ff61a67d37c833fdadfabf655dd..06211578ae7b39d304026f97fc1329480dbc6acd 100644 (file)
--- a/tc/m_bpf.c
+++ b/tc/m_bpf.c
@@ -1,5 +1,5 @@
 /*
- * m_bpf.c     BFP based action module
+ * m_bpf.c     BPF based action module
  *
  *              This program is free software; you can redistribute it and/or
  *              modify it under the terms of the GNU General Public License
@@ -35,7 +35,8 @@ static void explain(void)
        fprintf(stderr, " bytecode-file FILE\n");
        fprintf(stderr, "\n");
        fprintf(stderr, "eBPF use case:\n");
-       fprintf(stderr, " object-file FILE [ section ACT_NAME ] [ export UDS_FILE ]\n");
+       fprintf(stderr, " object-file FILE [ section ACT_NAME ] [ export UDS_FILE ]");
+       fprintf(stderr, " [ verbose ]\n");
        fprintf(stderr, "\n");
        fprintf(stderr, "Where BPF_BYTECODE := \'s,c t f k,c t f k,c t f k,...\'\n");
        fprintf(stderr, "c,t,f,k and s are decimals; s denotes number of 4-tuples\n");
@@ -78,12 +79,13 @@ static int parse_bpf(struct action_util *a, int *argc_p, char ***argv_p,
 
        while (argc > 0) {
                if (matches(*argv, "run") == 0) {
-                       bool from_file;
+                       bool from_file, bpf_verbose;
                        int ret;
 
                        NEXT_ARG();
 opt_bpf:
                        bpf_sec_name = bpf_default_section(bpf_type);
+                       bpf_verbose = false;
                        seen_run = true;
 
                        if (strcmp(*argv, "bytecode-file") == 0 ||
@@ -118,11 +120,17 @@ opt_bpf:
                                        bpf_uds_name = *argv;
                                        NEXT_ARG();
                                }
+                               if (strcmp(*argv, "verbose") == 0 ||
+                                   strcmp(*argv, "verb") == 0) {
+                                       bpf_verbose = true;
+                                       NEXT_ARG();
+                               }
 
                                PREV_ARG();
                        }
 
-                       ret = ebpf ? bpf_open_object(bpf_obj, bpf_type, bpf_sec_name) :
+                       ret = ebpf ? bpf_open_object(bpf_obj, bpf_type, bpf_sec_name,
+                                                    bpf_verbose) :
                                     bpf_parse_ops(argc, argv, bpf_ops, from_file);
                        if (ret < 0) {
                                fprintf(stderr, "%s\n", ebpf ?

diff --git a/tc/tc_bpf.c b/tc/tc_bpf.c
index 7c282aaba6cb69813b5c65d07049eacc9d1f29ec..59493dff787f4891fa935730ad5428e77f0a7676 100644 (file)
--- a/tc/tc_bpf.c
+++ b/tc/tc_bpf.c
@@ -192,6 +192,7 @@ struct bpf_map_data {
  * verifier we still want to hand something descriptive to the user.
  */
 static char bpf_log_buf[65536];
+static bool bpf_verbose;
 
 static struct bpf_elf_st bpf_st;
 
@@ -207,8 +208,10 @@ static void bpf_dump_error(const char *format, ...)
        vfprintf(stderr, format, vl);
        va_end(vl);
 
-       fprintf(stderr, "%s\n", bpf_log_buf);
-       memset(bpf_log_buf, 0, sizeof(bpf_log_buf));
+       if (bpf_log_buf[0]) {
+               fprintf(stderr, "%s\n", bpf_log_buf);
+               memset(bpf_log_buf, 0, sizeof(bpf_log_buf));
+       }
 }
 
 static void bpf_save_finfo(int file_fd)
@@ -284,8 +287,11 @@ static int bpf_prog_attach(enum bpf_prog_type type, const struct bpf_insn *insns
 {
        int prog_fd = bpf_prog_load(type, insns, size, license);
 
-       if (prog_fd < 0)
-               bpf_dump_error("BPF program rejected: %s\n", strerror(errno));
+       if (prog_fd < 0 || bpf_verbose) {
+               bpf_dump_error("%s: %s\n", prog_fd < 0 ?
+                              "BPF program rejected" :
+                              "BPF program verification", strerror(errno));
+       }
 
        return prog_fd;
 }
@@ -555,7 +561,8 @@ static int bpf_fetch_prog(Elf *elf_fd, GElf_Ehdr *elf_hdr, bool *sec_seen,
        return prog_fd;
 }
 
-int bpf_open_object(const char *path, enum bpf_prog_type type, const char *sec)
+int bpf_open_object(const char *path, enum bpf_prog_type type,
+                   const char *sec, bool verbose)
 {
        char license[ELF_MAX_LICENSE_LEN];
        int file_fd, prog_fd = -1, ret;
@@ -589,6 +596,8 @@ int bpf_open_object(const char *path, enum bpf_prog_type type, const char *sec)
        }
 
        memset(license, 0, sizeof(license));
+       bpf_verbose = verbose;
+
        if (!bpf_may_skip_map_creation(file_fd))
                bpf_maps_init();
 

diff --git a/tc/tc_bpf.h b/tc/tc_bpf.h
index 4a239aab0f390d9ae8b9b8f5d28feca1764b25b5..5a697e5cd8350a6d5e6e981a35a76e845200cf2e 100644 (file)
--- a/tc/tc_bpf.h
+++ b/tc/tc_bpf.h
@@ -36,7 +36,7 @@ const char *bpf_default_section(const enum bpf_prog_type type);
 
 #ifdef HAVE_ELF
 int bpf_open_object(const char *path, enum bpf_prog_type type,
-                   const char *sec);
+                   const char *sec, bool verbose);
 
 int bpf_send_map_fds(const char *path, const char *obj);
 int bpf_recv_map_fds(const char *path, int *fds, struct bpf_map_aux *aux,
@@ -59,7 +59,7 @@ static inline int bpf(int cmd, union bpf_attr *attr, unsigned int size)
 }
 #else
 static inline int bpf_open_object(const char *path, enum bpf_prog_type type,
-                                 const char *sec)
+                                 const char *sec, bool verbose)
 {
        fprintf(stderr, "No ELF library support compiled in.\n");
        errno = ENOSYS;