X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=src%2Fcommon.c;h=50a563a3ea41b95bb64e19c6451f749ec076313c;hb=8d9b00298d5dd8c6e4f3315aa2a0ae4d3684f55d;hp=1eec286a54d27c4b1731a80082912704e61dde10;hpb=c1e47ad7b5e5e889fb86250f714b299e4bf8819f;p=collectd.git

diff --git a/src/common.c b/src/common.c
index 1eec286a..50a563a3 100644
--- a/src/common.c
+++ b/src/common.c
@@ -46,35 +46,54 @@ static char *rra_def[] =
 static int rra_num = 9;
 #endif /* HAVE_LIBRRD */
 
-void
-sstrncpy(char *d, const char *s, int len)
+void sstrncpy (char *d, const char *s, int len)
 {
-	strncpy(d, s, len);
-	d[len - 1] = 0;
+	strncpy (d, s, len);
+	d[len - 1] = '\0';
 }
 
-char *
-sstrdup(const char *s)
+char *sstrdup (const char *s)
 {
-	char *r = strdup(s);
-	if(r == NULL) {
-		DBG("Not enough memory.");
+	char *r;
+
+	if (s == NULL)
+		return (NULL);
+
+	if((r = strdup (s)) == NULL)
+	{
+		DBG ("Not enough memory.");
 		exit(3);
 	}
-	return r;
+
+	return (r);
 }
 
-void *
-smalloc(size_t size)
+void *smalloc (size_t size)
 {
-	void *r = malloc(size);
-	if(r == NULL) {
+	void *r;
+
+	if ((r = malloc (size)) == NULL)
+	{
 		DBG("Not enough memory.");
 		exit(3);
 	}
+
 	return r;
 }
 
+#if 0
+void sfree (void **ptr)
+{
+	if (ptr == NULL)
+		return;
+
+	if (*ptr != NULL)
+		free (*ptr);
+
+	*ptr = NULL;
+}
+#endif
+
 int strsplit (char *string, char **fields, size_t size)
 {
 	size_t i;
@@ -94,32 +113,175 @@ int strsplit (char *string, char **fields, size_t size)
 	return (i);
 }
 
+int strjoin (char *dst, size_t dst_len,
+		char **fields, size_t fields_num,
+		const char *sep)
+{
+	int field_len;
+	int sep_len;
+	int i;
+
+	memset (dst, '\0', dst_len);
+
+	if (fields_num <= 0)
+		return (-1);
+
+	sep_len = 0;
+	if (sep != NULL)
+		sep_len = strlen (sep);
+
+	for (i = 0; i < fields_num; i++)
+	{
+		if ((i > 0) && (sep_len > 0))
+		{
+			if (dst_len <= sep_len)
+				return (-1);
+
+			strncat (dst, sep, dst_len);
+			dst_len -= sep_len;
+		}
+
+		field_len = strlen (fields[i]);
+
+		if (dst_len <= field_len)
+			return (-1);
+
+		strncat (dst, fields[i], dst_len);
+		dst_len -= field_len;
+	}
+
+	return (strlen (dst));
+}
+
+int escape_slashes (char *buf, int buf_len)
+{
+	int i;
+
+	if (strcmp (buf, "/") == 0)
+	{
+		if (buf_len < 5)
+			return (-1);
+
+		strncpy (buf, "root", buf_len);
+		return (0);
+	}
+
+	/* Move one to the left */
+	memmove (buf, buf + 1, buf_len - 1);
+
+	for (i = 0; i < buf_len - 1; i++)
+	{
+		if (buf[i] == '\0')
+			break;
+		else if (buf[i] == '/')
+			buf[i] = '_';
+	}
+	buf[i] = '\0';
+
+	return (0);
+}
+
 #ifdef HAVE_LIBRRD
-int check_create_dir (char *dir)
+int check_create_dir (const char *file_orig)
 {
 	struct stat statbuf;
 
-	if (stat (dir, &statbuf) == -1)
+	char  file_copy[512];
+	char  dir[512];
+	int   dir_len = 512;
+	char *fields[16];
+	int   fields_num;
+	char *ptr;
+	int   last_is_file = 1;
+	int   len;
+	int   i;
+
+	/*
+	 * Sanity checks first
+	 */
+	if (file_orig == NULL)
+		return (-1);
+
+	if ((len = strlen (file_orig)) < 1)
+		return (-1);
+	else if (len >= 512)
+		return (-1);
+
+	/*
+	 * If `file_orig' ends in a slash the last component is a directory,
+	 * otherwise it's a file. Act accordingly..
+	 */
+	if (file_orig[len - 1] == '/')
+		last_is_file = 0;
+
+	/*
+	 * Create a copy for `strtok' to destroy
+	 */
+	strncpy (file_copy, file_orig, 512);
+	file_copy[511] = '\0';
+
+	/*
+	 * Break into components. This will eat up several slashes in a row and
+	 * remove leading and trailing slashes..
+	 */
+	ptr = file_copy;
+	fields_num = 0;
+	while ((fields[fields_num] = strtok (ptr, "/")) != NULL)
 	{
-		if (errno == ENOENT)
+		ptr = NULL;
+		fields_num++;
+
+		if (fields_num >= 16)
+			break;
+	}
+
+	/*
+	 * For each component, do..
+	 */
+	for (i = 0; i < (fields_num - last_is_file); i++)
+	{
+		/*
+		 * Do not create directories that start with a dot. This
+		 * prevents `../../' attacks and other likely malicious
+		 * behavior.
+		 */
+		if (fields[i][0] == '.')
+		{
+			syslog (LOG_ERR, "Cowardly refusing to create a directory that begins with a `.' (dot): `%s'", file_orig);
+			return (-2);
+		}
+
+		/*
+		 * Join the components together again
+		 */
+		if (strjoin (dir, dir_len, fields, i + 1, "/") < 0)
 		{
-			if (mkdir (dir, 0755) == -1)
+			syslog (LOG_ERR, "strjoin failed: `%s', component #%i", file_orig, i);
+			return (-1);
+		}
+
+		if (stat (dir, &statbuf) == -1)
+		{
+			if (errno == ENOENT)
 			{
-				syslog (LOG_ERR, "mkdir (%s): %s", dir, strerror (errno));
+				if (mkdir (dir, 0755) == -1)
+				{
+					syslog (LOG_ERR, "mkdir (%s): %s", dir, strerror (errno));
+					return (-1);
+				}
+			}
+			else
+			{
+				syslog (LOG_ERR, "stat (%s): %s", dir, strerror (errno));
 				return (-1);
 			}
 		}
-		else
+		else if (!S_ISDIR (statbuf.st_mode))
 		{
-			syslog (LOG_ERR, "stat (%s): %s", dir, strerror (errno));
+			syslog (LOG_ERR, "stat (%s): Not a directory!", dir);
 			return (-1);
 		}
 	}
-	else if (!S_ISDIR (statbuf.st_mode))
-	{
-		syslog (LOG_ERR, "stat %s: Not a directory!", dir);
-		return (-1);
-	}
 
 	return (0);
 }
@@ -131,6 +293,9 @@ int rrd_create_file (char *filename, char **ds_def, int ds_num)
 	int i, j;
 	int status = 0;
 
+	if (check_create_dir (filename))
+		return (-1);
+
 	argc = ds_num + rra_num + 4;
 
 	if ((argv = (char **) malloc (sizeof (char *) * (argc + 1))) == NULL)
@@ -176,9 +341,6 @@ int rrd_update_file (char *host, char *file, char *values,
 	/* host == NULL => local mode */
 	if (host != NULL)
 	{
-		if (check_create_dir (host))
-			return (-1);
-
 		if (snprintf (full_file, 1024, "%s/%s", host, file) >= 1024)
 			return (-1);
 	}