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>

tools/bpf/bpftool/common.c

@@ -66,8 +66,8 @@ int open_obj_pinned_any(char *path, enum bpf_obj_type exp_type)
 
 	fd = bpf_obj_get(path);
 	if (fd < 0) {
-		err("bpf obj get (%s): %s\n", path,
+		p_err("bpf obj get (%s): %s", path,
-		    errno == EACCES && !is_bpffs(dirname(path)) ?
+		      errno == EACCES && !is_bpffs(dirname(path)) ?
 		    "directory not in bpf file system (bpffs)" :
 		    strerror(errno));
 		return -1;
@@ -79,7 +79,7 @@ int open_obj_pinned_any(char *path, enum bpf_obj_type exp_type)
 		return type;
 	}
 	if (type != exp_type) {
-		err("incorrect object type: %s\n", get_fd_type_name(type));
+		p_err("incorrect object type: %s", get_fd_type_name(type));
 		close(fd);
 		return -1;
 	}
@@ -95,14 +95,14 @@ int do_pin_any(int argc, char **argv, int (*get_fd_by_id)(__u32))
 	int fd;
 
 	if (!is_prefix(*argv, "id")) {
-		err("expected 'id' got %s\n", *argv);
+		p_err("expected 'id' got %s", *argv);
 		return -1;
 	}
 	NEXT_ARG();
 
 	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_ARG();
@@ -112,15 +112,15 @@ int do_pin_any(int argc, char **argv, int (*get_fd_by_id)(__u32))
 
 	fd = 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_pin(fd, *argv);
 	close(fd);
 	if (err) {
-		err("can't pin the object (%s): %s\n", *argv,
+		p_err("can't pin the object (%s): %s", *argv,
-		    errno == EACCES && !is_bpffs(dirname(*argv)) ?
+		      errno == EACCES && !is_bpffs(dirname(*argv)) ?
 		    "directory not in bpf file system (bpffs)" :
 		    strerror(errno));
 		return -1;
@@ -153,11 +153,11 @@ int get_fd_type(int fd)
 
 	n = readlink(path, buf, sizeof(buf));
 	if (n < 0) {
-		err("can't read link type: %s\n", strerror(errno));
+		p_err("can't read link type: %s", strerror(errno));
 		return -1;
 	}
 	if (n == sizeof(path)) {
-		err("can't read link type: path too long!\n");
+		p_err("can't read link type: path too long!");
 		return -1;
 	}
 
@@ -181,7 +181,7 @@ char *get_fdinfo(int fd, const char *key)
 
 	fdi = fopen(path, "r");
 	if (!fdi) {
-		err("can't open fdinfo: %s\n", strerror(errno));
+		p_err("can't open fdinfo: %s", strerror(errno));
 		return NULL;
 	}
 
@@ -196,7 +196,7 @@ char *get_fdinfo(int fd, const char *key)
 
 		value = strchr(line, '\t');
 		if (!value || !value[1]) {
-			err("malformed fdinfo!?\n");
+			p_err("malformed fdinfo!?");
 			free(line);
 			return NULL;
 		}
@@ -209,7 +209,7 @@ char *get_fdinfo(int fd, const char *key)
 		return line;
 	}
 
-	err("key '%s' not found in fdinfo\n", key);
+	p_err("key '%s' not found in fdinfo", key);
 	free(line);
 	fclose(fdi);
 	return NULL;

tools/bpf/bpftool/main.c

@@ -158,20 +158,20 @@ static int do_batch(int argc, char **argv)
 	int i;
 
 	if (argc < 2) {
-		err("too few parameters for batch\n");
+		p_err("too few parameters for batch");
 		return -1;
 	} else if (!is_prefix(*argv, "file")) {
-		err("expected 'file', got: %s\n", *argv);
+		p_err("expected 'file', got: %s", *argv);
 		return -1;
 	} else if (argc > 2) {
-		err("too many parameters for batch\n");
+		p_err("too many parameters for batch");
 		return -1;
 	}
 	NEXT_ARG();
 
 	fp = fopen(*argv, "r");
 	if (!fp) {
-		err("Can't open file (%s): %s\n", *argv, strerror(errno));
+		p_err("Can't open file (%s): %s", *argv, strerror(errno));
 		return -1;
 	}
 
@@ -189,8 +189,8 @@ static int do_batch(int argc, char **argv)
 		while (n_argv[n_argc]) {
 			n_argc++;
 			if (n_argc == ARRAY_SIZE(n_argv)) {
-				err("line %d has too many arguments, skip\n",
+				p_err("line %d has too many arguments, skip",
-				    lines);
+				      lines);
 				n_argc = 0;
 				break;
 			}
@@ -225,7 +225,7 @@ static int do_batch(int argc, char **argv)
 		perror("reading batch file failed");
 		err = -1;
 	} else {
-		info("processed %d lines\n", lines);
+		p_info("processed %d lines", lines);
 		err = 0;
 	}
 err_close:
@@ -279,7 +279,7 @@ int main(int argc, char **argv)
 	if (json_output) {
 		json_wtr = jsonw_new(stdout);
 		if (!json_wtr) {
-			err("failed to create JSON writer\n");
+			p_err("failed to create JSON writer");
 			return -1;
 		}
 		jsonw_pretty(json_wtr, pretty_output);

tools/bpf/bpftool/main.h

@@ -45,15 +45,11 @@
 
 #include "json_writer.h"
 
-#define err(msg...)	fprintf(stderr, "Error: " msg)
-#define warn(msg...)	fprintf(stderr, "Warning: " msg)
-#define info(msg...)	fprintf(stderr, msg)
-
 #define ptr_to_u64(ptr)	((__u64)(unsigned long)(ptr))
 
 #define NEXT_ARG()	({ argc--; argv++; if (argc < 0) usage(); })
 #define NEXT_ARGP()	({ (*argc)--; (*argv)++; if (*argc < 0) usage(); })
-#define BAD_ARG()	({ err("what is '%s'?\n", *argv); -1; })
+#define BAD_ARG()	({ p_err("what is '%s'?\n", *argv); -1; })
 
 #define BPF_TAG_FMT	"%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx"
 
@@ -97,4 +93,35 @@ int prog_parse_fd(int *argc, char ***argv);
 void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes);
 void print_hex_data_json(uint8_t *data, size_t len);
 
+static inline void p_err(const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	if (json_output) {
+		jsonw_start_object(json_wtr);
+		jsonw_name(json_wtr, "error");
+		jsonw_vprintf_enquote(json_wtr, fmt, ap);
+		jsonw_end_object(json_wtr);
+	} else {
+		fprintf(stderr, "Error: ");
+		vfprintf(stderr, fmt, ap);
+		fprintf(stderr, "\n");
+	}
+	va_end(ap);
+}
+
+static inline void p_info(const char *fmt, ...)
+{
+	va_list ap;
+
+	if (json_output)
+		return;
+
+	va_start(ap, fmt);
+	vfprintf(stderr, fmt, ap);
+	fprintf(stderr, "\n");
+	va_end(ap);
+}
+
 #endif

tools/bpf/bpftool/map.c

@@ -81,19 +81,19 @@ static unsigned int get_possible_cpus(void)
 
 	fd = open("/sys/devices/system/cpu/possible", O_RDONLY);
 	if (fd < 0) {
-		err("can't open sysfs possible cpus\n");
+		p_err("can't open sysfs possible cpus");
 		exit(-1);
 	}
 
 	n = read(fd, buf, sizeof(buf));
 	if (n < 2) {
-		err("can't read sysfs possible cpus\n");
+		p_err("can't read sysfs possible cpus");
 		exit(-1);
 	}
 	close(fd);
 
 	if (n == sizeof(buf)) {
-		err("read sysfs possible cpus overflow\n");
+		p_err("read sysfs possible cpus overflow");
 		exit(-1);
 	}
 
@@ -161,14 +161,14 @@ static int map_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_map_get_fd_by_id(id);
 		if (fd < 0)
-			err("get map by id (%u): %s\n", id, strerror(errno));
+			p_err("get map by id (%u): %s", id, strerror(errno));
 		return fd;
 	} else if (is_prefix(**argv, "pinned")) {
 		char *path;
@@ -181,7 +181,7 @@ static int map_parse_fd(int *argc, char ***argv)
 		return open_obj_pinned_any(path, BPF_OBJ_MAP);
 	}
 
-	err("expected 'id' or 'pinned', got: '%s'?\n", **argv);
+	p_err("expected 'id' or 'pinned', got: '%s'?", **argv);
 	return -1;
 }
 
@@ -197,7 +197,7 @@ map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len)
 
 	err = bpf_obj_get_info_by_fd(fd, info, info_len);
 	if (err) {
-		err("can't get map info: %s\n", strerror(errno));
+		p_err("can't get map info: %s", strerror(errno));
 		close(fd);
 		return err;
 	}
@@ -288,14 +288,14 @@ static char **parse_bytes(char **argv, const char *name, unsigned char *val,
 	while (i < n && argv[i]) {
 		val[i] = strtoul(argv[i], &endptr, 0);
 		if (*endptr) {
-			err("error parsing byte: %s\n", argv[i]);
+			p_err("error parsing byte: %s", argv[i]);
 			return NULL;
 		}
 		i++;
 	}
 
 	if (i != n) {
-		err("%s expected %d bytes got %d\n", name, n, i);
+		p_err("%s expected %d bytes got %d", name, n, i);
 		return NULL;
 	}
 
@@ -309,16 +309,16 @@ static int parse_elem(char **argv, struct bpf_map_info *info,
 	if (!*argv) {
 		if (!key && !value)
 			return 0;
-		err("did not find %s\n", key ? "key" : "value");
+		p_err("did not find %s", key ? "key" : "value");
 		return -1;
 	}
 
 	if (is_prefix(*argv, "key")) {
 		if (!key) {
 			if (key_size)
-				err("duplicate key\n");
+				p_err("duplicate key");
 			else
-				err("unnecessary key\n");
+				p_err("unnecessary key");
 			return -1;
 		}
 
@@ -333,9 +333,9 @@ static int parse_elem(char **argv, struct bpf_map_info *info,
 
 		if (!value) {
 			if (value_size)
-				err("duplicate value\n");
+				p_err("duplicate value");
 			else
-				err("unnecessary value\n");
+				p_err("unnecessary value");
 			return -1;
 		}
 
@@ -345,11 +345,11 @@ static int parse_elem(char **argv, struct bpf_map_info *info,
 			int argc = 2;
 
 			if (value_size != 4) {
-				err("value smaller than 4B for map in map?\n");
+				p_err("value smaller than 4B for map in map?");
 				return -1;
 			}
 			if (!argv[0] || !argv[1]) {
-				err("not enough value arguments for map in map\n");
+				p_err("not enough value arguments for map in map");
 				return -1;
 			}
 
@@ -363,11 +363,11 @@ static int parse_elem(char **argv, struct bpf_map_info *info,
 			int argc = 2;
 
 			if (value_size != 4) {
-				err("value smaller than 4B for map of progs?\n");
+				p_err("value smaller than 4B for map of progs?");
 				return -1;
 			}
 			if (!argv[0] || !argv[1]) {
-				err("not enough value arguments for map of progs\n");
+				p_err("not enough value arguments for map of progs");
 				return -1;
 			}
 
@@ -388,7 +388,7 @@ static int parse_elem(char **argv, struct bpf_map_info *info,
 	} else if (is_prefix(*argv, "any") || is_prefix(*argv, "noexist") ||
 		   is_prefix(*argv, "exist")) {
 		if (!flags) {
-			err("flags specified multiple times: %s\n", *argv);
+			p_err("flags specified multiple times: %s", *argv);
 			return -1;
 		}
 
@@ -403,7 +403,7 @@ static int parse_elem(char **argv, struct bpf_map_info *info,
 				  value_size, NULL, value_fd);
 	}
 
-	err("expected key or value, got: %s\n", *argv);
+	p_err("expected key or value, got: %s", *argv);
 	return -1;
 }
 
@@ -499,22 +499,21 @@ static int do_show(int argc, char **argv)
 		if (err) {
 			if (errno == ENOENT)
 				break;
-			err("can't get next map: %s\n", strerror(errno));
+			p_err("can't get next map: %s%s", strerror(errno),
-			if (errno == EINVAL)
+			      errno == EINVAL ? " -- kernel too old?" : "");
-				err("kernel too old?\n");
 			return -1;
 		}
 
 		fd = bpf_map_get_fd_by_id(id);
 		if (fd < 0) {
-			err("can't get map by id (%u): %s\n",
+			p_err("can't get map by id (%u): %s",
-			    id, strerror(errno));
+			      id, strerror(errno));
 			return -1;
 		}
 
 		err = bpf_obj_get_info_by_fd(fd, &info, &len);
 		if (err) {
-			err("can't get map info: %s\n", strerror(errno));
+			p_err("can't get map info: %s", strerror(errno));
 			close(fd);
 			return -1;
 		}
@@ -547,7 +546,7 @@ static int do_dump(int argc, char **argv)
 		return -1;
 
 	if (map_is_map_of_maps(info.type) || map_is_map_of_progs(info.type)) {
-		err("Dumping maps of maps and program maps not supported\n");
+		p_err("Dumping maps of maps and program maps not supported");
 		close(fd);
 		return -1;
 	}
@@ -555,7 +554,7 @@ static int do_dump(int argc, char **argv)
 	key = malloc(info.key_size);
 	value = alloc_value(&info);
 	if (!key || !value) {
-		err("mem alloc failed\n");
+		p_err("mem alloc failed");
 		err = -1;
 		goto exit_free;
 	}
@@ -577,9 +576,19 @@ static int do_dump(int argc, char **argv)
 			else
 				print_entry_plain(&info, key, value);
 		} else {
-			info("can't lookup element with key: ");
+			if (json_output) {
-			fprint_hex(stderr, key, info.key_size, " ");
+				jsonw_name(json_wtr, "key");
-			fprintf(stderr, "\n");
+				print_hex_data_json(key, info.key_size);
+				jsonw_name(json_wtr, "value");
+				jsonw_start_object(json_wtr);
+				jsonw_string_field(json_wtr, "error",
+						   "can't lookup element");
+				jsonw_end_object(json_wtr);
+			} else {
+				p_info("can't lookup element with key: ");
+				fprint_hex(stderr, key, info.key_size, " ");
+				fprintf(stderr, "\n");
+			}
 		}
 
 		prev_key = key;
@@ -619,7 +628,7 @@ static int do_update(int argc, char **argv)
 	key = malloc(info.key_size);
 	value = alloc_value(&info);
 	if (!key || !value) {
-		err("mem alloc failed");
+		p_err("mem alloc failed");
 		err = -1;
 		goto exit_free;
 	}
@@ -631,7 +640,7 @@ static int do_update(int argc, char **argv)
 
 	err = bpf_map_update_elem(fd, key, value, flags);
 	if (err) {
-		err("update failed: %s\n", strerror(errno));
+		p_err("update failed: %s", strerror(errno));
 		goto exit_free;
 	}
 
@@ -663,7 +672,7 @@ static int do_lookup(int argc, char **argv)
 	key = malloc(info.key_size);
 	value = alloc_value(&info);
 	if (!key || !value) {
-		err("mem alloc failed");
+		p_err("mem alloc failed");
 		err = -1;
 		goto exit_free;
 	}
@@ -687,7 +696,7 @@ static int do_lookup(int argc, char **argv)
 			printf("\n\nNot found\n");
 		}
 	} else {
-		err("lookup failed: %s\n", strerror(errno));
+		p_err("lookup failed: %s", strerror(errno));
 	}
 
 exit_free:
@@ -716,7 +725,7 @@ static int do_getnext(int argc, char **argv)
 	key = malloc(info.key_size);
 	nextkey = malloc(info.key_size);
 	if (!key || !nextkey) {
-		err("mem alloc failed");
+		p_err("mem alloc failed");
 		err = -1;
 		goto exit_free;
 	}
@@ -733,7 +742,7 @@ static int do_getnext(int argc, char **argv)
 
 	err = bpf_map_get_next_key(fd, key, nextkey);
 	if (err) {
-		err("can't get next key: %s\n", strerror(errno));
+		p_err("can't get next key: %s", strerror(errno));
 		goto exit_free;
 	}
 
@@ -786,7 +795,7 @@ static int do_delete(int argc, char **argv)
 
 	key = malloc(info.key_size);
 	if (!key) {
-		err("mem alloc failed");
+		p_err("mem alloc failed");
 		err = -1;
 		goto exit_free;
 	}
@@ -797,7 +806,7 @@ static int do_delete(int argc, char **argv)
 
 	err = bpf_map_delete_elem(fd, key);
 	if (err)
-		err("delete failed: %s\n", strerror(errno));
+		p_err("delete failed: %s", strerror(errno));
 
 exit_free:
 	free(key);

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",
+			p_err("can't get prog by id (%u): %s",
-			    id, strerror(errno));
+			      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",
+			p_err("can't get prog info (%u): %s",
-			    id, strerror(errno));
+			      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));
+			p_err("can't get next program: %s%s", strerror(errno),
-			if (errno == EINVAL)
+			      errno == EINVAL ? " -- kernel too old?" : "");
-				err("kernel too old?\n");
 			err = -1;
 			break;
 		}
 
 		fd = bpf_prog_get_fd_by_id(id);
 		if (fd < 0) {
-			err("can't get prog by id (%u): %s\n",
+			p_err("can't get prog by id (%u): %s",
-			    id, strerror(errno));
+			      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,
+			p_err("can't open file %s: %s", filepath,
-			    strerror(errno));
+			      strerror(errno));
 			goto err_free;
 		}
 
 		n = write(fd, buf, *member_len);
 		close(fd);
 		if (n != *member_len) {
-			err("error writing output file: %s\n",
+			p_err("error writing output file: %s",
-			    n < 0 ? strerror(errno) : "short write");
+			      n < 0 ? strerror(errno) : "short write");
 			goto err_free;
 		}
 	} else {