libustctl: cleanup ustctl_get_online_pids functions

Cleanup the ustctl_get_online_pids functions, checking more errors
and making the allocation strategy sane.

Signed-off-by: Nils Carlson <nils.carlson@ericsson.com>

diff --git a/libustctl/libustctl.c b/libustctl/libustctl.c
index 356d5ef7235536a67b405f07431aed96018fbe69..c781283974035d5ed48b3c42e60ba5f026b46153 100644 (file)
--- a/libustctl/libustctl.c
+++ b/libustctl/libustctl.c
@@ -88,11 +88,29 @@ int ustctl_connect_pid(pid_t pid)
        return sock;
 }
 
-static void get_pids_in_dir(DIR *dir, pid_t **pid_list,
+static int realloc_pid_list(pid_t **pid_list, unsigned int *pid_list_size)
+{
+       pid_t *new_pid_list;
+       unsigned int new_pid_list_size = 2 * *pid_list_size;
+
+       new_pid_list = realloc(*pid_list,
+                              new_pid_list_size * sizeof(pid_t));
+       if (!*new_pid_list) {
+               return -1;
+       }
+
+       *pid_list = new_pid_list;
+       *pid_list_size = new_pid_list_size;
+
+       return 0;
+}
+
+static int get_pids_in_dir(DIR *dir, pid_t **pid_list,
+                           unsigned int *pid_list_index,
                            unsigned int *pid_list_size)
 {
        struct dirent *dirent;
-       unsigned int read_pid;
+       long read_pid;
 
        while ((dirent = readdir(dir))) {
                if (!strcmp(dirent->d_name, ".") ||
@@ -103,29 +121,40 @@ static void get_pids_in_dir(DIR *dir, pid_t **pid_list,
                        continue;
                }
 
-               sscanf(dirent->d_name, "%u", &read_pid);
+               errno = 0;
+               read_pid = strtol(dirent->d_name, NULL, 10);
+               if (errno) {
+                       continue;
+               }
 
-               (*pid_list)[*pid_list_size - 1] = read_pid;
-               /* FIXME: Here we previously called pid_is_online, which
+               /*
+                * FIXME: Here we previously called pid_is_online, which
                 * always returned 1, now I replaced it with just 1.
                 * We need to figure out an intelligent way of solving
                 * this, maybe connect-disconnect.
                 */
                if (1) {
-                       (*pid_list_size)++;
-                       *pid_list = realloc(*pid_list,
-                                           *pid_list_size * sizeof(pid_t));
+
+                       (*pid_list)[(*pid_list_index)++] = read_pid;
+
+                       if (*pid_list_index == *pid_list_size) {
+                               if (realloc_pid_list(pid_list, pid_list_size)) {
+                                       return -1;
+                               }
+                       }
                }
        }
 
-       (*pid_list)[*pid_list_size - 1] = 0; /* Array end */
+       (*pid_list)[*pid_list_index] = 0; /* Array end */
+
+       return 0;
 }
 
 static pid_t *get_pids_non_root(void)
 {
        char *dir_name;
        DIR *dir;
-       unsigned int pid_list_size = 1;
+       unsigned int pid_list_index = 0, pid_list_size = 1;
        pid_t *pid_list = NULL;
 
        dir_name = ustcomm_user_sock_dir();
@@ -143,13 +172,9 @@ static pid_t *get_pids_non_root(void)
                goto close_dir;
        }
 
-       get_pids_in_dir(dir, &pid_list, &pid_list_size);
-
-       if (pid_list[0] == 0) {
-               /* No PID at all */
-               free(pid_list);
-               pid_list = NULL;
-               goto close_dir;
+       if (get_pids_in_dir(dir, &pid_list, &pid_list_index, &pid_list_size)) {
+               /* if any errors are encountered, force freeing of the list */
+               pid_list[0] = 0;
        }
 
 close_dir:
@@ -165,9 +190,10 @@ static pid_t *get_pids_root(void)
 {
        char *dir_name;
        DIR *tmp_dir, *dir;
-       unsigned int pid_list_size = 1;
+       unsigned int pid_list_index = 0, pid_list_size = 1;
        pid_t *pid_list = NULL;
        struct dirent *dirent;
+       int result;
 
        tmp_dir = opendir(USER_TMP_DIR);
        if (!tmp_dir) {
@@ -184,7 +210,8 @@ static pid_t *get_pids_root(void)
                if (!strncmp(dirent->d_name, USER_SOCK_DIR_BASE,
                             strlen(USER_SOCK_DIR_BASE))) {
 
-                       if (asprintf(&dir_name, USER_TMP_DIR "/%s", dirent->d_name) < 0) {
+                       if (asprintf(&dir_name, USER_TMP_DIR "/%s",
+                                    dirent->d_name) < 0) {
                                goto close_tmp_dir;
                        }
 
@@ -196,9 +223,19 @@ static pid_t *get_pids_root(void)
                                continue;
                        }
 
-                       get_pids_in_dir(dir, &pid_list, &pid_list_size);
+                       result = get_pids_in_dir(dir, &pid_list, &pid_list_index,
+                                                &pid_list_size);
 
                        closedir(dir);
+
+                       if (result) {
+                               /*
+                                * if any errors are encountered,
+                                * force freeing of the list
+                                */
+                               pid_list[0] = 0;
+                               break;
+                       }
                }
        }
 
@@ -210,11 +247,21 @@ close_tmp_dir:
 
 pid_t *ustctl_get_online_pids(void)
 {
+       pid_t *pid_list;
+
        if (geteuid()) {
-               return get_pids_non_root();
+               pid_list = get_pids_non_root();
        } else {
-               return get_pids_root();
+               pid_list = get_pids_root();
+       }
+
+       if (pid_list && pid_list[0] == 0) {
+               /* No PID at all */
+               free(pid_list);
+               pid_list = NULL;
        }
+
+       return pid_list;
 }
 
 /**