msg: enforce at least one word

Also, move some stuff to net.c where it belongs.

5 files changed, 111 insertions, 79 deletions

diff --git a/src/command.c b/src/command.c
index 8e24e7f..5661edc 100644
--- a/src/command.c
+++ b/src/command.c
@@ -113,12 +113,12 @@ int cmd_dispatcher_handle_msg(const struct cmd_dispatcher *dispatcher, int conn_
 	if (numof_words == 0)
 		goto unknown;
 
-	const char **words = msg_get_words(request);
+	const char *actual_cmd = msg_get_first_word(request);
 
 	for (size_t i = 0; i < dispatcher->numof_cmds; ++i) {
 		struct cmd_desc *cmd = &dispatcher->cmds[i];
 
-		if (strcmp(cmd->name, words[0]))
+		if (strcmp(cmd->name, actual_cmd))
 			continue;
 
 		ret = cmd->handler(conn_fd, request, dispatcher->ctx, &response);
diff --git a/src/msg.c b/src/msg.c
index 583c5e5..4da0154 100644
--- a/src/msg.c
+++ b/src/msg.c
@@ -28,6 +28,11 @@ const char **msg_get_words(const struct msg *msg)
 	return msg->argv;
 }
 
+const char *msg_get_first_word(const struct msg *msg)
+{
+	return msg->argv[0];
+}
+
 int msg_success(struct msg **msg)
 {
 	static const char *argv[] = {"success", NULL};
@@ -127,6 +132,11 @@ int msg_from_argv(struct msg **_msg, const char **argv)
 	for (const char **s = argv; *s; ++s)
 		++msg->argc;
 
+	if (!msg->argc) {
+		log_err("A message must contain at least one string\n");
+		goto free;
+	}
+
 	ret = msg_copy_argv(msg, argv);
 	if (ret < 0)
 		goto free;
@@ -140,78 +150,14 @@ free:
 	return -1;
 }
 
-static uint32_t calc_buf_size(const struct msg *msg)
-{
-	uint32_t len = 0;
-	for (size_t i = 0; i < msg->argc; ++i)
-		len += strlen(msg->argv[i]) + 1;
-	return len;
-}
-
-static size_t calc_argv_len(const void *buf, size_t len)
-{
-	size_t argc = 0;
-	for (const char *it = buf; it < (const char *)buf + len; it += strlen(it) + 1)
-		++argc;
-	return argc;
-}
-
-static void argv_pack(char *dest, const struct msg *msg)
-{
-	for (size_t i = 0; i < msg->argc; ++i) {
-		strcpy(dest, msg->argv[i]);
-		dest += strlen(msg->argv[i]) + 1;
-	}
-}
-
-static int argv_unpack(struct msg *msg, const char *src)
-{
-	size_t copied = 0;
-
-	msg->argv = calloc(msg->argc + 1, sizeof(const char *));
-	if (!msg->argv) {
-		log_errno("calloc");
-		return -1;
-	}
-
-	for (copied = 0; copied < msg->argc; ++copied) {
-		msg->argv[copied] = strdup(src);
-		if (!msg->argv[copied]) {
-			log_errno("strdup");
-			goto free;
-		}
-
-		src += strlen(msg->argv[copied]) + 1;
-	}
-
-	return 0;
-
-free:
-	for (size_t i = 0; i < copied; ++i) {
-		free((char *)msg->argv[i]);
-	}
-
-	msg_free(msg);
-
-	return -1;
-}
-
 int msg_send(int fd, const struct msg *msg)
 {
 	struct buf *buf = NULL;
 	int ret = 0;
 
-	uint32_t size = calc_buf_size(msg);
-	char *data = malloc(size);
-	if (!data) {
-		log_errno("malloc");
-		return -1;
-	}
-	argv_pack(data, msg);
-
-	ret = buf_create(&buf, data, size);
+	ret = buf_pack_strings(&buf, msg->argc, msg->argv);
 	if (ret < 0)
-		goto free_data;
+		return ret;
 
 	ret = net_send_buf(fd, buf);
 	if (ret < 0)
@@ -220,9 +166,6 @@ int msg_send(int fd, const struct msg *msg)
 destroy_buf:
 	buf_destroy(buf);
 
-free_data:
-	free(data);
-
 	return ret;
 }
 
@@ -257,12 +200,15 @@ int msg_recv(int fd, struct msg **_msg)
 		goto destroy_buf;
 	}
 
-	msg->argc = calc_argv_len(buf_get_data(buf), buf_get_size(buf));
-
-	ret = argv_unpack(msg, buf_get_data(buf));
+	ret = buf_unpack_strings(buf, &msg->argc, &msg->argv);
 	if (ret < 0)
 		goto free_msg;
 
+	if (!msg->argc) {
+		log_err("A message must contain at least one string\n");
+		goto free_msg;
+	}
+
 	*_msg = msg;
 	goto destroy_buf;
 
diff --git a/src/msg.h b/src/msg.h
index e6541f4..158c5e6 100644
--- a/src/msg.h
+++ b/src/msg.h
@@ -12,8 +12,14 @@
 
 struct msg;
 
+int msg_from_argv(struct msg **, const char **argv);
+void msg_free(struct msg *);
+
+int msg_copy(struct msg **, const struct msg *);
+
 size_t msg_get_length(const struct msg *);
 const char **msg_get_words(const struct msg *);
+const char *msg_get_first_word(const struct msg *);
 
 int msg_success(struct msg **);
 int msg_error(struct msg **);
@@ -21,11 +27,6 @@ int msg_error(struct msg **);
 int msg_is_success(const struct msg *);
 int msg_is_error(const struct msg *);
 
-int msg_copy(struct msg **, const struct msg *);
-void msg_free(struct msg *);
-
-int msg_from_argv(struct msg **, const char **argv);
-
 int msg_recv(int fd, struct msg **);
 int msg_send(int fd, const struct msg *);
 
diff --git a/src/net.c b/src/net.c
index 0a6ef85..c3a4b5e 100644
--- a/src/net.c
+++ b/src/net.c
@@ -247,6 +247,88 @@ void *buf_get_data(const struct buf *buf)
 	return buf->data;
 }
 
+static size_t count_strings(const void *_data, size_t size)
+{
+	const unsigned char *data = (const unsigned char *)_data;
+	const unsigned char *it = memchr(data, '\0', size);
+
+	size_t numof_strings = 0;
+	while (it) {
+		it = memchr(it + 1, '\0', size - (it - data) - 1);
+		++numof_strings;
+	}
+
+	return numof_strings;
+}
+
+int buf_pack_strings(struct buf **_buf, size_t argc, const char **argv)
+{
+	struct buf *buf = malloc(sizeof(struct buf));
+	if (!buf) {
+		log_errno("malloc");
+		return -1;
+	}
+
+	buf->size = 0;
+	for (size_t i = 0; i < argc; ++i)
+		buf->size += strlen(argv[i]) + 1;
+
+	buf->data = malloc(buf->size);
+	if (!buf->data) {
+		log_errno("malloc");
+		goto free_buf;
+	}
+
+	char *it = (char *)buf->data;
+	for (size_t i = 0; i < argc; ++i) {
+		it = stpcpy(it, argv[i]) + 1;
+	}
+
+	*_buf = buf;
+	return 0;
+
+free_buf:
+	free(buf);
+
+	return -1;
+}
+
+int buf_unpack_strings(const struct buf *buf, size_t *_argc, const char ***_argv)
+{
+	size_t argc = count_strings(buf->data, buf->size);
+	size_t copied = 0;
+
+	const char **argv = calloc(argc + 1, sizeof(const char *));
+	if (!argv) {
+		log_errno("calloc");
+		return -1;
+	}
+
+	const char *it = (const char *)buf->data;
+	for (copied = 0; copied < argc; ++copied) {
+		argv[copied] = strdup(it);
+		if (!argv[copied]) {
+			log_errno("strdup");
+			goto free;
+		}
+
+		it += strlen(argv[copied]) + 1;
+	}
+
+	*_argc = argc;
+	*_argv = argv;
+	return 0;
+
+free:
+	for (size_t i = 0; i < copied; ++i) {
+		free((char *)argv[i]);
+	}
+
+	free(argv);
+
+	return -1;
+}
+
 int net_send_buf(int fd, const struct buf *buf)
 {
 	int ret = 0;
diff --git a/src/net.h b/src/net.h
index 84968cb..a8acb57 100644
--- a/src/net.h
+++ b/src/net.h
@@ -26,6 +26,9 @@ void buf_destroy(struct buf *);
 uint32_t buf_get_size(const struct buf *);
 void *buf_get_data(const struct buf *);
 
+int buf_pack_strings(struct buf **, size_t argc, const char **argv);
+int buf_unpack_strings(const struct buf *, size_t *argc, const char ***argv);
+
 int net_send_buf(int fd, const struct buf *);
 int net_recv_buf(int fd, struct buf **);