shared: procfs_file_alloca: handle pid==0

[elogind.git] / src / shared / util.c

diff --git a/src/shared/util.c b/src/shared/util.c
index 8d7cf5398f981e248bf0301f32b60260c9307d5e..50dac708040973e95afc0ef8c1cb6f3be1ce9405 100644 (file)
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -495,10 +495,7 @@ int get_starttime_of_pid(pid_t pid, unsigned long long *st) {
         assert(pid >= 0);
         assert(st);
 
-        if (pid == 0)
-                p = "/proc/self/stat";
-        else
-                p = procfs_file_alloca(pid, "stat");
+        p = procfs_file_alloca(pid, "stat");
 
         f = fopen(p, "re");
         if (!f)
@@ -573,10 +570,7 @@ int get_process_comm(pid_t pid, char **name) {
         assert(name);
         assert(pid >= 0);
 
-        if (pid == 0)
-                p = "/proc/self/comm";
-        else
-                p = procfs_file_alloca(pid, "comm");
+        p = procfs_file_alloca(pid, "comm");
 
         r = read_one_line_file(p, name);
         if (r == -ENOENT)
@@ -594,10 +588,7 @@ int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char *
         assert(line);
         assert(pid >= 0);
 
-        if (pid == 0)
-                p = "/proc/self/cmdline";
-        else
-                p = procfs_file_alloca(pid, "cmdline");
+        p = procfs_file_alloca(pid, "cmdline");
 
         f = fopen(p, "re");
         if (!f)
@@ -716,10 +707,7 @@ int get_process_capeff(pid_t pid, char **capeff) {
         assert(capeff);
         assert(pid >= 0);
 
-        if (pid == 0)
-                p = "/proc/self/status";
-        else
-                p = procfs_file_alloca(pid, "status");
+        p = procfs_file_alloca(pid, "status");
 
         return get_status_field(p, "\nCapEff:", capeff);
 }
@@ -732,10 +720,7 @@ int get_process_exe(pid_t pid, char **name) {
         assert(pid >= 0);
         assert(name);
 
-        if (pid == 0)
-                p = "/proc/self/exe";
-        else
-                p = procfs_file_alloca(pid, "exe");
+        p = procfs_file_alloca(pid, "exe");
 
         r = readlink_malloc(p, name);
         if (r < 0)
@@ -2549,10 +2534,7 @@ int get_ctty_devnr(pid_t pid, dev_t *d) {
 
         assert(pid >= 0);
 
-        if (pid == 0)
-                fn = "/proc/self/stat";
-        else
-                fn = procfs_file_alloca(pid, "stat");
+        fn = procfs_file_alloca(pid, "stat");
 
         f = fopen(fn, "re");
         if (!f)
@@ -5095,10 +5077,7 @@ int getenv_for_pid(pid_t pid, const char *field, char **_value) {
         assert(field);
         assert(_value);
 
-        if (pid == 0)
-                path = "/proc/self/environ";
-        else
-                path = procfs_file_alloca(pid, "environ");
+        path = procfs_file_alloca(pid, "environ");
 
         f = fopen(path, "re");
         if (!f)
@@ -6117,3 +6096,66 @@ bool pid_valid(pid_t pid) {
 
         return errno != ESRCH;
 }
+
+int getpeercred(int fd, struct ucred *ucred) {
+        socklen_t n = sizeof(struct ucred);
+        struct ucred u;
+        int r;
+
+        assert(fd >= 0);
+        assert(ucred);
+
+        r = getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &u, &n);
+        if (r < 0)
+                return -errno;
+
+        if (n != sizeof(struct ucred))
+                return -EIO;
+
+        /* Check if the data is actually useful and not suppressed due
+         * to namespacing issues */
+        if (u.pid <= 0)
+                return -ENODATA;
+
+        *ucred = u;
+        return 0;
+}
+
+int getpeersec(int fd, char **ret) {
+        socklen_t n = 64;
+        char *s;
+        int r;
+
+        assert(fd >= 0);
+        assert(ret);
+
+        s = new0(char, n);
+        if (!s)
+                return -ENOMEM;
+
+        r = getsockopt(fd, SOL_SOCKET, SO_PEERSEC, s, &n);
+        if (r < 0) {
+                free(s);
+
+                if (errno != ERANGE)
+                        return -errno;
+
+                s = new0(char, n);
+                if (!s)
+                        return -ENOMEM;
+
+                r = getsockopt(fd, SOL_SOCKET, SO_PEERSEC, s, &n);
+                if (r < 0) {
+                        free(s);
+                        return -errno;
+                }
+        }
+
+        if (isempty(s)) {
+                free(s);
+                return -ENOTSUP;
+        }
+
+        *ret = s;
+        return 0;
+}