service: optionally call into PAM when dropping priviliges

[elogind.git] / src / util.c

diff --git a/src/util.c b/src/util.c
index 2bc90da3d2b20bf92ad239c265d42f924e968e77..ed0991a68b45d1a4b699f6de08ca54dcf81797e5 100644 (file)
--- a/src/util.c
+++ b/src/util.c
@@ -43,6 +43,7 @@
 #include <sys/poll.h>
 #include <libgen.h>
 #include <ctype.h>
+#include <sys/prctl.h>
 
 #include "macro.h"
 #include "util.h"
@@ -222,6 +223,13 @@ void close_nointr_nofail(int fd) {
         errno = saved_errno;
 }
 
+void close_many(const int fds[], unsigned n_fd) {
+        unsigned i;
+
+        for (i = 0; i < n_fd; i++)
+                close_nointr_nofail(fds[i]);
+}
+
 int parse_boolean(const char *v) {
         assert(v);
 
@@ -2141,6 +2149,39 @@ int dir_is_empty(const char *path) {
         return r;
 }
 
+unsigned long long random_ull(void) {
+        int fd;
+        uint64_t ull;
+        ssize_t r;
+
+        if ((fd = open("/dev/urandom", O_RDONLY|O_CLOEXEC|O_NOCTTY)) < 0)
+                goto fallback;
+
+        r = loop_read(fd, &ull, sizeof(ull));
+        close_nointr_nofail(fd);
+
+        if (r != sizeof(ull))
+                goto fallback;
+
+        return ull;
+
+fallback:
+        return random() * RAND_MAX + random();
+}
+
+void rename_process(const char name[8]) {
+        assert(name);
+
+        prctl(PR_SET_NAME, name);
+
+        /* This is a like a poor man's setproctitle(). The string
+         * passed should fit in 7 chars (i.e. the length of
+         * "systemd") */
+
+        if (program_invocation_name)
+                strncpy(program_invocation_name, name, strlen(program_invocation_name));
+}
+
 static const char *const ioprio_class_table[] = {
         [IOPRIO_CLASS_NONE] = "none",
         [IOPRIO_CLASS_RT] = "realtime",