tools: bpftool: turn err() and info() macros into functions

Turn err() and info() macros into functions.

In order to avoid naming conflicts with variables in the code, rename
them as p_err() and p_info() respectively.

The behavior of these functions is similar to the one of the macros for
plain output. However, when JSON output is requested, these macros
return a JSON-formatted "error" object instead of printing a message to
stderr.

To handle error messages correctly with JSON, a modification was brought
to their behavior nonetheless: the functions now append a end-of-line
character at the end of the message. This way, we can remove end-of-line
characters at the end of the argument strings, and not have them in the
JSON output.

All error messages are formatted to hold in a single call to p_err(), in
order to produce a single JSON field.

Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 25 insertions, 26 deletions

diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index 43e49799a624..41bd5390b4fc 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -104,21 +104,21 @@ static int prog_fd_by_tag(unsigned char *tag)
         while (true) {
                 err = bpf_prog_get_next_id(id, &id);
                 if (err) {
-                        err("%s\n", strerror(errno));
+                        p_err("%s", strerror(errno));
                         return -1;
                 }
 
                 fd = bpf_prog_get_fd_by_id(id);
                 if (fd < 0) {
-                        err("can't get prog by id (%u): %s\n",
-                            id, strerror(errno));
+                        p_err("can't get prog by id (%u): %s",
+                              id, strerror(errno));
                         return -1;
                 }
 
                 err = bpf_obj_get_info_by_fd(fd, &info, &len);
                 if (err) {
-                        err("can't get prog info (%u): %s\n",
-                            id, strerror(errno));
+                        p_err("can't get prog info (%u): %s",
+                              id, strerror(errno));
                         close(fd);
                         return -1;
                 }
@@ -142,14 +142,14 @@ int prog_parse_fd(int *argc, char ***argv)
 
                 id = strtoul(**argv, &endptr, 0);
                 if (*endptr) {
-                        err("can't parse %s as ID\n", **argv);
+                        p_err("can't parse %s as ID", **argv);
                         return -1;
                 }
                 NEXT_ARGP();
 
                 fd = bpf_prog_get_fd_by_id(id);
                 if (fd < 0)
-                        err("get by id (%u): %s\n", id, strerror(errno));
+                        p_err("get by id (%u): %s", id, strerror(errno));
                 return fd;
         } else if (is_prefix(**argv, "tag")) {
                 unsigned char tag[BPF_TAG_SIZE];
@@ -159,7 +159,7 @@ int prog_parse_fd(int *argc, char ***argv)
                 if (sscanf(**argv, BPF_TAG_FMT, tag, tag + 1, tag + 2,
                            tag + 3, tag + 4, tag + 5, tag + 6, tag + 7)
                     != BPF_TAG_SIZE) {
-                        err("can't parse tag\n");
+                        p_err("can't parse tag");
                         return -1;
                 }
                 NEXT_ARGP();
@@ -176,7 +176,7 @@ int prog_parse_fd(int *argc, char ***argv)
                 return open_obj_pinned_any(path, BPF_OBJ_PROG);
         }
 
-        err("expected 'id', 'tag' or 'pinned', got: '%s'?\n", **argv);
+        p_err("expected 'id', 'tag' or 'pinned', got: '%s'?", **argv);
         return -1;
 }
 
@@ -311,7 +311,7 @@ static int show_prog(int fd)
 
         err = bpf_obj_get_info_by_fd(fd, &info, &len);
         if (err) {
-                err("can't get prog info: %s\n", strerror(errno));
+                p_err("can't get prog info: %s", strerror(errno));
                 return -1;
         }
 
@@ -349,17 +349,16 @@ static int do_show(int argc, char **argv)
                                 err = 0;
                                 break;
                         }
-                        err("can't get next program: %s\n", strerror(errno));
-                        if (errno == EINVAL)
-                                err("kernel too old?\n");
+                        p_err("can't get next program: %s%s", strerror(errno),
+                              errno == EINVAL ? " -- kernel too old?" : "");
                         err = -1;
                         break;
                 }
 
                 fd = bpf_prog_get_fd_by_id(id);
                 if (fd < 0) {
-                        err("can't get prog by id (%u): %s\n",
-                            id, strerror(errno));
+                        p_err("can't get prog by id (%u): %s",
+                              id, strerror(errno));
                         err = -1;
                         break;
                 }
@@ -498,7 +497,7 @@ static int do_dump(int argc, char **argv)
                 member_len = &info.xlated_prog_len;
                 member_ptr = &info.xlated_prog_insns;
         } else {
-                err("expected 'xlated' or 'jited', got: %s\n", *argv);
+                p_err("expected 'xlated' or 'jited', got: %s", *argv);
                 return -1;
         }
         NEXT_ARG();
@@ -513,7 +512,7 @@ static int do_dump(int argc, char **argv)
         if (is_prefix(*argv, "file")) {
                 NEXT_ARG();
                 if (!argc) {
-                        err("expected file path\n");
+                        p_err("expected file path");
                         return -1;
                 }
 
@@ -531,12 +530,12 @@ static int do_dump(int argc, char **argv)
 
         err = bpf_obj_get_info_by_fd(fd, &info, &len);
         if (err) {
-                err("can't get prog info: %s\n", strerror(errno));
+                p_err("can't get prog info: %s", strerror(errno));
                 return -1;
         }
 
         if (!*member_len) {
-                info("no instructions returned\n");
+                p_info("no instructions returned");
                 close(fd);
                 return 0;
         }
@@ -545,7 +544,7 @@ static int do_dump(int argc, char **argv)
 
         buf = malloc(buf_size);
         if (!buf) {
-                err("mem alloc failed\n");
+                p_err("mem alloc failed");
                 close(fd);
                 return -1;
         }
@@ -558,28 +557,28 @@ static int do_dump(int argc, char **argv)
         err = bpf_obj_get_info_by_fd(fd, &info, &len);
         close(fd);
         if (err) {
-                err("can't get prog info: %s\n", strerror(errno));
+                p_err("can't get prog info: %s", strerror(errno));
                 goto err_free;
         }
 
         if (*member_len > buf_size) {
-                err("too many instructions returned\n");
+                p_err("too many instructions returned");
                 goto err_free;
         }
 
         if (filepath) {
                 fd = open(filepath, O_WRONLY | O_CREAT | O_TRUNC, 0600);
                 if (fd < 0) {
-                        err("can't open file %s: %s\n", filepath,
-                            strerror(errno));
+                        p_err("can't open file %s: %s", filepath,
+                              strerror(errno));
                         goto err_free;
                 }
 
                 n = write(fd, buf, *member_len);
                 close(fd);
                 if (n != *member_len) {
-                        err("error writing output file: %s\n",
-                            n < 0 ? strerror(errno) : "short write");
+                        p_err("error writing output file: %s",
+                              n < 0 ? strerror(errno) : "short write");
                         goto err_free;
                 }
         } else {