util: unify getenv() logic for other PID

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

diff --git a/src/shared/util.c b/src/shared/util.c
index a3873a931818ec4595e5e1f538c629b5768c0439..ba2456283962574753eaa1670c6f3373bfe1ee46 100644 (file)
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -56,6 +56,7 @@
 #include <glob.h>
 #include <grp.h>
 #include <sys/mman.h>
+#include <sys/statvfs.h>
 
 #include "macro.h"
 #include "util.h"
@@ -1690,7 +1691,8 @@ char *cescape(const char *s) {
 
         /* Does C style string escaping. */
 
-        if (!(r = new(char, strlen(s)*4 + 1)))
+        r = new(char, strlen(s)*4 + 1);
+        if (!r)
                 return NULL;
 
         for (f = s, t = r; *f; f++)
@@ -4285,6 +4287,15 @@ bool tty_is_vc(const char *tty) {
         return vtnr_from_tty(tty) >= 0;
 }
 
+bool tty_is_console(const char *tty) {
+        assert(tty);
+
+        if (startswith(tty, "/dev/"))
+                tty += 5;
+
+        return streq(tty, "console");
+}
+
 int vtnr_from_tty(const char *tty) {
         int i, r;
 
@@ -4318,8 +4329,10 @@ bool tty_is_vc_resolve(const char *tty) {
         if (startswith(tty, "/dev/"))
                 tty += 5;
 
-        /* Resolve where /dev/console is pointing to */
-        if (streq(tty, "console"))
+        /* Resolve where /dev/console is pointing to, if /sys is
+         * actually ours (i.e. not read-only-mounted which is a sign
+         * for container setups) */
+        if (streq(tty, "console") && path_is_read_only_fs("/sys") <= 0)
                 if (read_one_line_file("/sys/class/tty/console/active", &active) >= 0) {
                         /* If multiple log outputs are configured the
                          * last one is what /dev/console points to */
@@ -4339,7 +4352,7 @@ bool tty_is_vc_resolve(const char *tty) {
 const char *default_term_for_tty(const char *tty) {
         assert(tty);
 
-        return tty_is_vc_resolve(tty) ? "TERM=linux" : "TERM=vt100";
+        return tty_is_vc_resolve(tty) ? "TERM=linux" : "TERM=vt102";
 }
 
 bool dirent_is_file(const struct dirent *de) {
@@ -6120,3 +6133,100 @@ int fork_agent(pid_t *pid, const int except[], unsigned n_except, const char *pa
         execv(path, l);
         _exit(EXIT_FAILURE);
 }
+
+int setrlimit_closest(int resource, const struct rlimit *rlim) {
+        struct rlimit highest, fixed;
+
+        assert(rlim);
+
+        if (setrlimit(resource, rlim) >= 0)
+                return 0;
+
+        if (errno != EPERM)
+                return -errno;
+
+        /* So we failed to set the desired setrlimit, then let's try
+         * to get as close as we can */
+        assert_se(getrlimit(resource, &highest) == 0);
+
+        fixed.rlim_cur = MIN(rlim->rlim_cur, highest.rlim_max);
+        fixed.rlim_max = MIN(rlim->rlim_max, highest.rlim_max);
+
+        if (setrlimit(resource, &fixed) < 0)
+                return -errno;
+
+        return 0;
+}
+
+int path_is_read_only_fs(const char *path) {
+        struct statvfs st;
+
+        assert(path);
+
+        if (statvfs(path, &st) < 0)
+                return -errno;
+
+        return !!(st.f_flag & ST_RDONLY);
+}
+
+int getenv_for_pid(pid_t pid, const char *field, char **_value) {
+        char path[sizeof("/proc/")-1+10+sizeof("/environ")], *value = NULL;
+        int r;
+        FILE *f;
+        bool done = false;
+        size_t l;
+
+        assert(field);
+        assert(_value);
+
+        if (pid == 0)
+                pid = getpid();
+
+        snprintf(path, sizeof(path), "/proc/%lu/environ", (unsigned long) pid);
+        char_array_0(path);
+
+        f = fopen(path, "re");
+        if (!f)
+                return -errno;
+
+        l = strlen(field);
+        r = 0;
+
+        do {
+                char line[LINE_MAX];
+                unsigned i;
+
+                for (i = 0; i < sizeof(line)-1; i++) {
+                        int c;
+
+                        c = getc(f);
+                        if (_unlikely_(c == EOF)) {
+                                done = true;
+                                break;
+                        } else if (c == 0)
+                                break;
+
+                        line[i] = c;
+                }
+                line[i] = 0;
+
+                if (memcmp(line, field, l) == 0 && line[l] == '=') {
+                        value = strdup(line + l + 1);
+                        if (!value) {
+                                r = -ENOMEM;
+                                break;
+                        }
+
+                        r = 1;
+                        break;
+                }
+
+        } while (!done);
+
+        fclose(f);
+
+        if (r >= 0)
+                *_value = value;
+
+        return r;
+}