[ltt-dev] [UST PATCH] libustctl: cleanup ustctl_get_online_pids functions

[Nils Carlson]

merged.

/Nils

On 04/04/2011 11:47 AM, Nils Carlson wrote:
> Cleanup the ustctl_get_online_pids functions, checking more errors
> and making the allocation strategy sane.
>
> Signed-off-by: Nils Carlson<nils.carlson at ericsson.com>
> ---
>   libustctl/libustctl.c |   91 +++++++++++++++++++++++++++++++++++++------------
>   1 files changed, 69 insertions(+), 22 deletions(-)
>
> diff --git a/libustctl/libustctl.c b/libustctl/libustctl.c
> index 356d5ef..c781283 100644
> --- 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;
>   }
>
>   /**