From: Thibault, Daniel <Daniel.Thibault@drdc-rddc.gc.ca>
Date: Fri, 27 Jan 2012 19:33:07 +0000 (-0500)
Subject: Document and enforce return values
X-Git-Tag: v2.0-pre19~30
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=27089920577ab0b7e237c4ec6ef2d8bdcea4a5ed;p=lttng-tools.git

Document and enforce return values

In config_read_session_name(), moved the malloc to the beginning, to
avoid the fscanf() loop from trying to write to a NULL

In config_add_session_name(), dealt with another snprintf() occurrence

Signed-off-by: Daniel U. Thibault <daniel.thibault@drdc-rddc.gc.ca>
Signed-off-by: David Goulet <dgoulet@efficios.com>
---

diff --git a/src/bin/lttng/commands/create.c b/src/bin/lttng/commands/create.c
index 3a2e136e5..99e5daa93 100644
--- a/src/bin/lttng/commands/create.c
+++ b/src/bin/lttng/commands/create.c
@@ -115,15 +115,14 @@ static int create_session()
 
 	ret = lttng_create_session(session_name, traces_path);
 	if (ret < 0) {
+		ret = CMD_ERROR;
 		goto error;
 	}
 
 	/* Init lttng session config */
 	ret = config_init(session_name);
 	if (ret < 0) {
-		if (ret == -1) {
-			ret = CMD_ERROR;
-		}
+		ret = CMD_ERROR;
 		goto error;
 	}
 
@@ -159,11 +158,10 @@ int cmd_create(int argc, const char **argv)
 	while ((opt = poptGetNextOpt(pc)) != -1) {
 		switch (opt) {
 		case OPT_HELP:
-			usage(stderr);
+			usage(stdout);
 			goto end;
 		case OPT_LIST_OPTIONS:
 			list_cmd_options(stdout, long_options);
-			ret = CMD_SUCCESS;
 			goto end;
 		default:
 			usage(stderr);
diff --git a/src/bin/lttng/conf.c b/src/bin/lttng/conf.c
index cdd264a5d..00991b081 100644
--- a/src/bin/lttng/conf.c
+++ b/src/bin/lttng/conf.c
@@ -32,7 +32,8 @@
 /*
  *  config_get_file_path
  *
- *  Return the path with '/CONFIG_FILENAME' added to it.
+ *  Returns the path with '/CONFIG_FILENAME' added to it;
+ *  path will be NULL if an error occurs.
  */
 char *config_get_file_path(char *path)
 {
@@ -50,7 +51,8 @@ char *config_get_file_path(char *path)
 /*
  *  open_config
  *
- *  Return an open FILE pointer to the config file.
+ *  Returns an open FILE pointer to the config file;
+ *  on error, NULL is returned.
  */
 static FILE *open_config(char *path, const char *mode)
 {
@@ -77,7 +79,9 @@ error:
 /*
  *  create_config_file
  *
- *  Create the empty config file a the path.
+ *  Creates the empty config file at the path.
+ *  On success, returns 0;
+ *  on error, returns -1.
  */
 static int create_config_file(char *path)
 {
@@ -101,6 +105,8 @@ error:
  *  write_config
  *
  *  Append data to the config file in file_path
+ *  On success, returns 0;
+ *  on error, returns -1.
  */
 static int write_config(char *file_path, size_t size, char *data)
 {
@@ -116,7 +122,7 @@ static int write_config(char *file_path, size_t size, char *data)
 
 	/* Write session name into config file */
 	len = fwrite(data, size, 1, fp);
-	if (len < 1) {
+	if (len != 1) {
 		ret = -1;
 	}
 	fclose(fp);
@@ -127,7 +133,7 @@ end:
 /*
  *  config_get_default_path
  *
- *  Return the HOME directory path. Caller MUST NOT free(3) the return pointer.
+ *  Returns the HOME directory path. Caller MUST NOT free(3) the return pointer.
  */
 char *config_get_default_path(void)
 {
@@ -137,7 +143,7 @@ char *config_get_default_path(void)
 /*
  *  config_destroy
  *
- *  Destroy directory config and file config.
+ *  Destroys directory config and file config.
  */
 void config_destroy(char *path)
 {
@@ -160,7 +166,9 @@ void config_destroy(char *path)
 /*
  *  config_read_session_name
  *
- *  Return sesson name from the config file.
+ *  Returns the session name from the config file.
+ *  The caller is responsible for freeing the returned string.
+ *  On error, NULL is returned.
  */
 char *config_read_session_name(char *path)
 {
@@ -168,6 +176,12 @@ char *config_read_session_name(char *path)
 	FILE *fp;
 	char var[NAME_MAX], *session_name;
 
+	session_name = malloc(NAME_MAX);
+	if (session_name == NULL) {
+		ERR("Out of memory");
+		goto error;
+	}
+
 	fp = open_config(path, "r");
 	if (fp == NULL) {
 		ERR("Can't find valid lttng config %s/.lttngrc", path);
@@ -175,7 +189,6 @@ char *config_read_session_name(char *path)
 		goto error;
 	}
 
-	session_name = malloc(NAME_MAX);
 	while (!feof(fp)) {
 		if ((ret = fscanf(fp, "%[^'=']=%s\n", var, session_name)) != 2) {
 			if (ret == -1) {
@@ -206,14 +219,21 @@ found:
  *  config_add_session_name
  *
  *  Write session name option to the config file.
+ *  On success, returns 0;
+ *  on error, returns -1.
  */
 int config_add_session_name(char *path, char *name)
 {
 	int ret;
 	char session_name[NAME_MAX];
 
+	/*
+	 * With GNU C <  2.1, snprintf returns -1 if the target buffer is too small;
+	 * With GNU C >= 2.1, snprintf returns the required size (excluding closing null)
+	 */
 	ret = snprintf(session_name, NAME_MAX, "session=%s\n", name);
-	if (ret < 0) {
+	if ((ret < 0) || (ret >= NAME_MAX)) {
+		ret = -1;
 		goto error;
 	}
 	ret = write_config(path, ret, session_name);
@@ -225,6 +245,8 @@ error:
  *  config_init
  *
  *  Init configuration directory and file.
+ *  On success, returns 0;
+ *  on error, returns -1.
  */
 int config_init(char *session_name)
 {