pam: use /proc/self/loginuid only if we have CAP_AUDIT_CONTROL

[elogind.git] / src / util.c

diff --git a/src/util.c b/src/util.c
index 5daafdf7c2088d78d19fe93b05629bc83d22e87e..75ad56fecf2f3e45d0bd193b59bde6746b74e365 100644 (file)
--- a/src/util.c
+++ b/src/util.c
@@ -50,6 +50,7 @@
 #include <linux/kd.h>
 #include <dlfcn.h>
 #include <sys/wait.h>
+#include <sys/capability.h>
 
 #include "macro.h"
 #include "util.h"
@@ -452,7 +453,7 @@ char **split_path_and_make_absolute(const char *p) {
 int get_parent_of_pid(pid_t pid, pid_t *_ppid) {
         int r;
         FILE *f;
-        char fn[132], line[256], *p;
+        char fn[PATH_MAX], line[LINE_MAX], *p;
         long unsigned ppid;
 
         assert(pid >= 0);
@@ -2063,7 +2064,7 @@ int chvt(int vt) {
 int read_one_char(FILE *f, char *ret, bool *need_nl) {
         struct termios old_termios, new_termios;
         char c;
-        char line[1024];
+        char line[LINE_MAX];
 
         assert(f);
         assert(ret);
@@ -2271,7 +2272,7 @@ int flush_fd(int fd) {
         pollfd.events = POLLIN;
 
         for (;;) {
-                char buf[1024];
+                char buf[LINE_MAX];
                 ssize_t l;
                 int r;
 
@@ -2897,7 +2898,7 @@ int getttyname_harder(int fd, char **r) {
 
 int get_ctty_devnr(dev_t *d) {
         int k;
-        char line[256], *p;
+        char line[LINE_MAX], *p;
         unsigned long ttynr;
         FILE *f;
 
@@ -2932,7 +2933,7 @@ int get_ctty_devnr(dev_t *d) {
 
 int get_ctty(char **r, dev_t *_devnr) {
         int k;
-        char fn[128], *s, *b, *p;
+        char fn[PATH_MAX], *s, *b, *p;
         dev_t devnr;
 
         assert(r);
@@ -4236,6 +4237,23 @@ void parse_syslog_priority(char **p, int *priority) {
         *p += k;
 }
 
+int have_effective_cap(int value) {
+        cap_t cap;
+        cap_flag_value_t fv;
+        int r;
+
+        if (!(cap = cap_get_proc()))
+                return -errno;
+
+        if (cap_get_flag(cap, value, CAP_EFFECTIVE, &fv) < 0)
+                r = -errno;
+        else
+                r = fv == CAP_SET;
+
+        cap_free(cap);
+        return r;
+}
+
 static const char *const ioprio_class_table[] = {
         [IOPRIO_CLASS_NONE] = "none",
         [IOPRIO_CLASS_RT] = "realtime",