Clean-up: uri_parse_str_urls: skip allocation when no uris are parsed

Meant as a way to silence a bogus Coverity warning. Skip the allocation
if both the ctrl and data uri parsing fails.

Coverity is confused and reports that uri_parse_str_urls() can return
a negative value after allocating the returned URIs (I don't see how,
and the path it reports is contradictory: 0 + 0 < 0.

I take the opportunity to rename the oddly--named "*_size" variables
which are not a "size", but rather a count of returned uris.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I79a82316ebd49d9fbbc5a8e67da64e44b789e2a7

diff --git a/src/common/uri.c b/src/common/uri.c
index d22e56e01f3a563d9b1166e03c472fbd2aa7e7e8..a774cb3cb70567d5c96f57e1b6878fb6d4c0d7ec 100644 (file)
--- a/src/common/uri.c
+++ b/src/common/uri.c
@@ -535,7 +535,7 @@ ssize_t uri_parse_str_urls(const char *ctrl_url, const char *data_url,
        unsigned int equal = 1, idx = 0;
        /* Add the "file://" size to the URL maximum size */
        char url[PATH_MAX + 7];
-       ssize_t size_ctrl = 0, size_data = 0, size;
+       ssize_t ctrl_uri_count = 0, data_uri_count = 0, uri_count;
        struct lttng_uri *ctrl_uris = NULL, *data_uris = NULL;
        struct lttng_uri *tmp_uris = NULL;
 
@@ -572,14 +572,14 @@ ssize_t uri_parse_str_urls(const char *ctrl_url, const char *data_url,
 
        /* Parse the control URL if there is one */
        if (ctrl_url && *ctrl_url != '\0') {
-               size_ctrl = uri_parse(ctrl_url, &ctrl_uris);
-               if (size_ctrl < 1) {
+               ctrl_uri_count = uri_parse(ctrl_url, &ctrl_uris);
+               if (ctrl_uri_count < 1) {
                        ERR("Unable to parse the URL %s", ctrl_url);
                        goto parse_error;
                }
 
                /* 1 and 2 are the only expected values on success. */
-               assert(size_ctrl == 1 || size_ctrl == 2);
+               assert(ctrl_uri_count == 1 || ctrl_uri_count == 2);
 
                /* At this point, we know there is at least one URI in the array */
                set_default_uri_attr(&ctrl_uris[0], LTTNG_STREAM_CONTROL);
@@ -591,7 +591,7 @@ ssize_t uri_parse_str_urls(const char *ctrl_url, const char *data_url,
                }
 
                /* URL are not equal but the control URL uses a net:// protocol */
-               if (size_ctrl == 2) {
+               if (ctrl_uri_count == 2) {
                        if (!equal) {
                                ERR("Control URL uses the net:// protocol and the data URL is "
                                                "different. Not allowed.");
@@ -611,16 +611,16 @@ ssize_t uri_parse_str_urls(const char *ctrl_url, const char *data_url,
                int ret;
 
                /* We have to parse the data URL in this case */
-               size_data = uri_parse(data_url, &data_uris);
-               if (size_data < 1) {
+               data_uri_count = uri_parse(data_url, &data_uris);
+               if (data_uri_count < 1) {
                        ERR("Unable to parse the URL %s", data_url);
                        goto error;
-               } else if (size_data == 2) {
+               } else if (data_uri_count == 2) {
                        ERR("Data URL can not be set with the net[4|6]:// protocol");
                        goto error;
                } else {
                        /* 1 and 2 are the only expected values on success. */
-                       assert(size_data == 1);
+                       assert(data_uri_count == 1);
                }
 
                set_default_uri_attr(&data_uris[0], LTTNG_STREAM_DATA);
@@ -634,10 +634,13 @@ ssize_t uri_parse_str_urls(const char *ctrl_url, const char *data_url,
                }
        }
 
-       /* Compute total size */
-       size = size_ctrl + size_data;
+       /* Compute total size. */
+       uri_count = ctrl_uri_count + data_uri_count;
+       if (uri_count <= 0) {
+               goto error;
+       }
 
-       tmp_uris = zmalloc(sizeof(struct lttng_uri) * size);
+       tmp_uris = zmalloc(sizeof(struct lttng_uri) * uri_count);
        if (tmp_uris == NULL) {
                PERROR("zmalloc uris");
                goto error;
@@ -645,7 +648,7 @@ ssize_t uri_parse_str_urls(const char *ctrl_url, const char *data_url,
 
        if (ctrl_uris) {
                /* It's possible the control URIs array contains more than one URI */
-               memcpy(tmp_uris, ctrl_uris, sizeof(struct lttng_uri) * size_ctrl);
+               memcpy(tmp_uris, ctrl_uris, sizeof(struct lttng_uri) * ctrl_uri_count);
                ++idx;
                free(ctrl_uris);
        }
@@ -657,7 +660,7 @@ ssize_t uri_parse_str_urls(const char *ctrl_url, const char *data_url,
 
        *uris = tmp_uris;
 
-       return size;
+       return uri_count;
 
 error:
        free(ctrl_uris);