cgroups: convert to strnprintf()

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

diff --git a/src/lxc/cgroups/cgfsng.c b/src/lxc/cgroups/cgfsng.c
index 5e1b3e632c5a2781e2918e3ce7d60060abd8c878..44b9d7c0080728567954bb2bf92297bed11bddfc 100644 (file)
--- a/src/lxc/cgroups/cgfsng.c
+++ b/src/lxc/cgroups/cgfsng.c
@@ -266,8 +266,8 @@ static char *lxc_cpumask_to_cpulist(uint32_t *bitarr, size_t nbits)
                if (!is_set(i, bitarr))
                        continue;
 
-               ret = snprintf(numstr, sizeof(numstr), "%zu", i);
-               if (ret < 0 || (size_t)ret >= sizeof(numstr))
+               ret = strnprintf(numstr, sizeof(numstr), "%zu", i);
+               if (ret < 0)
                        return NULL;
 
                ret = lxc_append_string(&cpulist, numstr);
@@ -1053,8 +1053,8 @@ __cgfsng_ops static void cgfsng_monitor_destroy(struct cgroup_ops *ops,
        }
        conf = handler->conf;
 
-       len = snprintf(pidstr, sizeof(pidstr), "%d", handler->monitor_pid);
-       if (len < 0 || (size_t)len >= sizeof(pidstr))
+       len = strnprintf(pidstr, sizeof(pidstr), "%d", handler->monitor_pid);
+       if (len < 0)
                return;
 
        for (int i = 0; ops->hierarchies[i]; i++) {
@@ -1471,9 +1471,15 @@ __cgfsng_ops static bool cgfsng_monitor_enter(struct cgroup_ops *ops,
        if (!handler || !handler->conf)
                return ret_set_errno(false, EINVAL);
 
-       monitor_len = snprintf(monitor, sizeof(monitor), "%d", handler->monitor_pid);
-       if (handler->transient_pid > 0)
-               transient_len = snprintf(transient, sizeof(transient), "%d", handler->transient_pid);
+       monitor_len = strnprintf(monitor, sizeof(monitor), "%d", handler->monitor_pid);
+       if (monitor_len < 0)
+               return false;
+
+       if (handler->transient_pid > 0) {
+               transient_len = strnprintf(transient, sizeof(transient), "%d", handler->transient_pid);
+               if (transient_len < 0)
+                       return false;
+       }
 
        for (int i = 0; ops->hierarchies[i]; i++) {
                struct hierarchy *h = ops->hierarchies[i];
@@ -1526,7 +1532,9 @@ __cgfsng_ops static bool cgfsng_payload_enter(struct cgroup_ops *ops,
        if (!handler || !handler->conf)
                return ret_set_errno(false, EINVAL);
 
-       len = snprintf(pidstr, sizeof(pidstr), "%d", handler->pid);
+       len = strnprintf(pidstr, sizeof(pidstr), "%d", handler->pid);
+       if (len < 0)
+               return false;
 
        for (int i = 0; ops->hierarchies[i]; i++) {
                struct hierarchy *h = ops->hierarchies[i];
@@ -2283,9 +2291,9 @@ static int cgroup_attach_leaf(const struct lxc_conf *conf, int unified_fd, pid_t
        if (ret < 0 && errno != EEXIST)
                return log_error_errno(-errno, errno, "Failed to create leaf cgroup \".lxc\"");
 
-       pidstr_len = snprintf(pidstr, sizeof(pidstr), INT64_FMT, (int64_t)pid);
-       if (pidstr_len < 0 || (size_t)pidstr_len >= sizeof(pidstr))
-               return ret_errno(EIO);
+       pidstr_len = strnprintf(pidstr, sizeof(pidstr), INT64_FMT, (int64_t)pid);
+       if (pidstr_len < 0)
+               return pidstr_len;
 
        ret = lxc_writeat(unified_fd, ".lxc/cgroup.procs", pidstr, pidstr_len);
        if (ret < 0)
@@ -2302,9 +2310,9 @@ static int cgroup_attach_leaf(const struct lxc_conf *conf, int unified_fd, pid_t
                char attach_cgroup[STRLITERALLEN(".lxc-/cgroup.procs") + INTTYPE_TO_STRLEN(int) + 1];
                char *slash = attach_cgroup;
 
-               ret = snprintf(attach_cgroup, sizeof(attach_cgroup), ".lxc-%d/cgroup.procs", idx);
-               if (ret < 0 || (size_t)ret >= sizeof(attach_cgroup))
-                       return ret_errno(EIO);
+               ret = strnprintf(attach_cgroup, sizeof(attach_cgroup), ".lxc-%d/cgroup.procs", idx);
+               if (ret < 0)
+                       return ret;
 
                /*
                 * This shouldn't really happen but the compiler might complain
@@ -2510,8 +2518,8 @@ __cgfsng_ops static bool cgfsng_attach(struct cgroup_ops *ops,
        if (!ops->hierarchies)
                return true;
 
-       len = snprintf(pidstr, sizeof(pidstr), "%d", pid);
-       if (len < 0 || (size_t)len >= sizeof(pidstr))
+       len = strnprintf(pidstr, sizeof(pidstr), "%d", pid);
+       if (len < 0)
                return false;
 
        for (int i = 0; ops->hierarchies[i]; i++) {
@@ -2827,11 +2835,13 @@ static int convert_devpath(const char *invalue, char *dest)
        if (ret < 0)
                return -1;
 
-       ret = snprintf(dest, 50, "%c %d:%d %s", device.type, device.major,
-                      device.minor, device.access);
-       if (ret < 0 || ret >= 50)
-               return log_error_errno(-1, ENAMETOOLONG, "Error on configuration value \"%c %d:%d %s\" (max 50 chars)",
-                                      device.type, device.major, device.minor, device.access);
+       ret = strnprintf(dest, 50, "%c %d:%d %s", device.type, device.major,
+                        device.minor, device.access);
+       if (ret < 0)
+               return log_error_errno(ret, -ret,
+                                      "Error on configuration value \"%c %d:%d %s\" (max 50 chars)",
+                                      device.type, device.major, device.minor,
+                                      device.access);
 
        return 0;
 }