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conmon: Don't use fixed size string buffers

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We build paths using g_build_filename and g_strdup_printf() instead
which means we don't have any arbitrary pathname lenght issue, and
the code becomes cleaner.

We also convert asprintf to g_strdup_printf so that we can use
the glib OOM checker instead of open coding it everywhere.

Signed-off-by: Alexander Larsson <alexl@redhat.com>
This commit is contained in:
Alexander Larsson 2017-06-22 11:57:47 +02:00
parent a7c61e4f9f
commit b269969216
1 changed files with 20 additions and 47 deletions
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65
conmon/conmon.c
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@ -352,14 +352,7 @@ next:
* Returns NULL on error. * Returns NULL on error.
*/ */
static char *process_cgroup_subsystem_path(int pid, const char *subsystem) { static char *process_cgroup_subsystem_path(int pid, const char *subsystem) {
_cleanup_free_ char *cgroups_file_path = NULL; _cleanup_free_ char *cgroups_file_path = g_strdup_printf("/proc/%d/cgroup", pid);
int rc;
rc = asprintf(&cgroups_file_path, "/proc/%d/cgroup", pid);
if (rc < 0) {
nwarn("Failed to allocate memory for cgroups file path");
return NULL;
}
_cleanup_fclose_ FILE *fp = NULL; _cleanup_fclose_ FILE *fp = NULL;
fp = fopen(cgroups_file_path, "re"); fp = fopen(cgroups_file_path, "re");
if (fp == NULL) { if (fp == NULL) {
@ -398,12 +391,7 @@ static char *process_cgroup_subsystem_path(int pid, const char *subsystem) {
*subpath = 0; *subpath = 0;
} }
rc = asprintf(&subsystem_path, "%s/%s%s", CGROUP_ROOT, subpath, path); subsystem_path = g_strdup_printf("%s/%s%s", CGROUP_ROOT, subpath, path);
if (rc < 0) {
nwarn("Failed to allocate memory for subsystemd path");
return NULL;
}
subsystem_path[strlen(subsystem_path) - 1] = '\0'; subsystem_path[strlen(subsystem_path) - 1] = '\0';
return subsystem_path; return subsystem_path;
} }
@ -800,11 +788,11 @@ int main(int argc, char *argv[])
{ {
int ret; int ret;
char cwd[PATH_MAX]; char cwd[PATH_MAX];
char default_pid_file[PATH_MAX]; _cleanup_free_ char *default_pid_file = NULL;
char attach_sock_path[PATH_MAX]; _cleanup_free_ char *attach_sock_path = NULL;
char ctl_fifo_path[PATH_MAX]; _cleanup_free_ char *ctl_fifo_path = NULL;
GError *err = NULL; GError *err = NULL;
_cleanup_free_ char *contents; _cleanup_free_ char *contents = NULL;
int cpid = -1; int cpid = -1;
int status; int status;
pid_t pid, main_pid, create_pid; pid_t pid, main_pid, create_pid;
@ -867,10 +855,7 @@ int main(int argc, char *argv[])
} }
if (opt_pid_file == NULL) { if (opt_pid_file == NULL) {
if (snprintf(default_pid_file, sizeof(default_pid_file), default_pid_file = g_strdup_printf ("%s/pidfile-%s", cwd, opt_cid);
"%s/pidfile-%s", cwd, opt_cid) < 0) {
nexit("Failed to generate the pidfile path");
}
opt_pid_file = default_pid_file; opt_pid_file = default_pid_file;
} }
@ -1119,7 +1104,7 @@ int main(int argc, char *argv[])
ninfo("container PID: %d", cpid); ninfo("container PID: %d", cpid);
/* Setup endpoint for attach */ /* Setup endpoint for attach */
char attach_symlink_dir_path[PATH_MAX] = { 0 }; _cleanup_free_ char *attach_symlink_dir_path = NULL;
struct sockaddr_un attach_addr = {0}; struct sockaddr_un attach_addr = {0};
if (!opt_exec) { if (!opt_exec) {
@ -1129,14 +1114,14 @@ int main(int argc, char *argv[])
* Create a symlink so we don't exceed unix domain socket * Create a symlink so we don't exceed unix domain socket
* path length limit. * path length limit.
*/ */
snprintf(attach_symlink_dir_path, PATH_MAX, "/var/run/crio/%s", opt_cuuid); attach_symlink_dir_path = g_build_filename("/var/run/crio", opt_cuuid, NULL);
if (unlink(attach_symlink_dir_path) == -1 && errno != ENOENT) { if (unlink(attach_symlink_dir_path) == -1 && errno != ENOENT) {
pexit("Failed to remove existing symlink for attach socket directory"); pexit("Failed to remove existing symlink for attach socket directory");
} }
if (symlink(opt_bundle_path, attach_symlink_dir_path) == -1) if (symlink(opt_bundle_path, attach_symlink_dir_path) == -1)
pexit("Failed to create symlink for attach socket"); pexit("Failed to create symlink for attach socket");
snprintf(attach_sock_path, PATH_MAX, "/var/run/crio/%s/attach", opt_cuuid); attach_sock_path = g_build_filename("/var/run/crio", opt_cuuid, "attach", NULL);
ninfo("attach sock path: %s", attach_sock_path); ninfo("attach sock path: %s", attach_sock_path);
strncpy(attach_addr.sun_path, attach_sock_path, sizeof(attach_addr.sun_path) - 1); strncpy(attach_addr.sun_path, attach_sock_path, sizeof(attach_addr.sun_path) - 1);
@ -1165,7 +1150,7 @@ int main(int argc, char *argv[])
_cleanup_close_ int ctlfd = -1; _cleanup_close_ int ctlfd = -1;
_cleanup_close_ int dummyfd = -1; _cleanup_close_ int dummyfd = -1;
if (!opt_exec) { if (!opt_exec) {
snprintf(ctl_fifo_path, PATH_MAX, "%s/ctl", opt_bundle_path); ctl_fifo_path = g_build_filename(opt_bundle_path, "ctl", NULL);
ninfo("ctl fifo path: %s", ctl_fifo_path); ninfo("ctl fifo path: %s", ctl_fifo_path);
if (mkfifo(ctl_fifo_path, 0666) == -1) if (mkfifo(ctl_fifo_path, 0666) == -1)
@ -1198,17 +1183,16 @@ int main(int argc, char *argv[])
} }
bool oom_handling_enabled = true; bool oom_handling_enabled = true;
char memory_cgroup_file_path[PATH_MAX]; _cleanup_free_ char *memory_cgroup_file_path = g_build_filename(memory_cgroup_path, "cgroup.event_control", NULL);
snprintf(memory_cgroup_file_path, PATH_MAX, "%s/cgroup.event_control", memory_cgroup_path);
if ((cfd = open(memory_cgroup_file_path, O_WRONLY | O_CLOEXEC)) == -1) { if ((cfd = open(memory_cgroup_file_path, O_WRONLY | O_CLOEXEC)) == -1) {
nwarn("Failed to open %s", memory_cgroup_file_path); nwarn("Failed to open %s", memory_cgroup_file_path);
oom_handling_enabled = false; oom_handling_enabled = false;
} }
if (oom_handling_enabled) { if (oom_handling_enabled) {
snprintf(memory_cgroup_file_path, PATH_MAX, "%s/memory.oom_control", memory_cgroup_path); _cleanup_free_ char *memory_cgroup_file_oom_path = g_build_filename(memory_cgroup_path, "memory.oom_control", NULL);
if ((ofd = open(memory_cgroup_file_path, O_RDONLY | O_CLOEXEC)) == -1) if ((ofd = open(memory_cgroup_file_oom_path, O_RDONLY | O_CLOEXEC)) == -1)
pexit("Failed to open %s", memory_cgroup_file_path); pexit("Failed to open %s", memory_cgroup_file_oom_path);
if ((oom_efd = eventfd(0, EFD_CLOEXEC)) == -1) if ((oom_efd = eventfd(0, EFD_CLOEXEC)) == -1)
pexit("Failed to create eventfd"); pexit("Failed to create eventfd");
@ -1270,27 +1254,16 @@ int main(int argc, char *argv[])
} }
if (!opt_exec) { if (!opt_exec) {
_cleanup_free_ char *status_str = NULL; _cleanup_free_ char *status_str = g_strdup_printf("%d", exit_status);
ret = asprintf(&status_str, "%d", exit_status); if (!g_file_set_contents("exit", status_str, -1, &err))
if (ret < 0) { nexit("Failed to write %s to exit file: %s\n",
pexit("Failed to allocate memory for status");
}
g_file_set_contents("exit", status_str,
strlen(status_str), &err);
if (err) {
fprintf(stderr,
"Failed to write %s to exit file: %s\n",
status_str, err->message); status_str, err->message);
g_error_free(err);
exit(1);
}
} else { } else {
/* Send the command exec exit code back to the parent */ /* Send the command exec exit code back to the parent */
write_sync_fd(sync_pipe_fd, exit_status, exit_message); write_sync_fd(sync_pipe_fd, exit_status, exit_message);
} }
if (attach_symlink_dir_path[0] != 0 && if (attach_symlink_dir_path != NULL &&
unlink(attach_symlink_dir_path) == -1 && errno != ENOENT) { unlink(attach_symlink_dir_path) == -1 && errno != ENOENT) {
pexit("Failed to remove symlink for attach socket directory"); pexit("Failed to remove symlink for attach socket directory");
} }