X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fshared%2Futil.c;h=ba2456283962574753eaa1670c6f3373bfe1ee46;hp=73e0a290b82e5e0a1de303f5dd7f0623a5c6368c;hb=ab94af9201496ea3aa59bbf2a01eb750fbd1c08a;hpb=71ecc858fa91a686a050bee51804d43865ce1acc

diff --git a/src/shared/util.c b/src/shared/util.c
index 73e0a290b..ba2456283 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -6,16 +6,16 @@
   Copyright 2010 Lennart Poettering
 
   systemd is free software; you can redistribute it and/or modify it
-  under the terms of the GNU General Public License as published by
-  the Free Software Foundation; either version 2 of the License, or
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
   (at your option) any later version.
 
   systemd is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-  General Public License for more details.
+  Lesser General Public License for more details.
 
-  You should have received a copy of the GNU General Public License
+  You should have received a copy of the GNU Lesser General Public License
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
@@ -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) {
@@ -6035,3 +6048,185 @@ int fd_inc_rcvbuf(int fd, size_t n) {
 
         return 1;
 }
+
+int fork_agent(pid_t *pid, const int except[], unsigned n_except, const char *path, ...) {
+        pid_t parent_pid, agent_pid;
+        int fd;
+        bool stdout_is_tty, stderr_is_tty;
+        unsigned n, i;
+        va_list ap;
+        char **l;
+
+        assert(pid);
+        assert(path);
+
+        parent_pid = getpid();
+
+        /* Spawns a temporary TTY agent, making sure it goes away when
+         * we go away */
+
+        agent_pid = fork();
+        if (agent_pid < 0)
+                return -errno;
+
+        if (agent_pid != 0) {
+                *pid = agent_pid;
+                return 0;
+        }
+
+        /* In the child:
+         *
+         * Make sure the agent goes away when the parent dies */
+        if (prctl(PR_SET_PDEATHSIG, SIGTERM) < 0)
+                _exit(EXIT_FAILURE);
+
+        /* Check whether our parent died before we were able
+         * to set the death signal */
+        if (getppid() != parent_pid)
+                _exit(EXIT_SUCCESS);
+
+        /* Don't leak fds to the agent */
+        close_all_fds(except, n_except);
+
+        stdout_is_tty = isatty(STDOUT_FILENO);
+        stderr_is_tty = isatty(STDERR_FILENO);
+
+        if (!stdout_is_tty || !stderr_is_tty) {
+                /* Detach from stdout/stderr. and reopen
+                 * /dev/tty for them. This is important to
+                 * ensure that when systemctl is started via
+                 * popen() or a similar call that expects to
+                 * read EOF we actually do generate EOF and
+                 * not delay this indefinitely by because we
+                 * keep an unused copy of stdin around. */
+                fd = open("/dev/tty", O_WRONLY);
+                if (fd < 0) {
+                        log_error("Failed to open /dev/tty: %m");
+                        _exit(EXIT_FAILURE);
+                }
+
+                if (!stdout_is_tty)
+                        dup2(fd, STDOUT_FILENO);
+
+                if (!stderr_is_tty)
+                        dup2(fd, STDERR_FILENO);
+
+                if (fd > 2)
+                        close(fd);
+        }
+
+        /* Count arguments */
+        va_start(ap, path);
+        for (n = 0; va_arg(ap, char*); n++)
+                ;
+        va_end(ap);
+
+        /* Allocate strv */
+        l = alloca(sizeof(char *) * (n + 1));
+
+        /* Fill in arguments */
+        va_start(ap, path);
+        for (i = 0; i <= n; i++)
+                l[i] = va_arg(ap, char*);
+        va_end(ap);
+
+        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;
+}