X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fshared%2Futmp-wtmp.c;h=7fb6fe3a6751602718039b2a8da55772cbaca2e7;hp=0a0180979b0ae7492a6f2987dafcbecf3583b64d;hb=e777ddfd71f3b2d3217ffe74f287388832915d0b;hpb=f04c0bd6ed2632f2e91c725388fd2f70859bfde5

diff --git a/src/shared/utmp-wtmp.c b/src/shared/utmp-wtmp.c
index 0a0180979..7fb6fe3a6 100644
--- a/src/shared/utmp-wtmp.c
+++ b/src/shared/utmp-wtmp.c
@@ -21,19 +21,18 @@
 
 #include <utmpx.h>
 #include <errno.h>
-#include <assert.h>
 #include <string.h>
 #include <sys/utsname.h>
 #include <fcntl.h>
 #include <unistd.h>
-#include <sys/poll.h>
+#include <poll.h>
 
 #include "macro.h"
 #include "path-util.h"
 #include "utmp-wtmp.h"
 
 int utmp_get_runlevel(int *runlevel, int *previous) {
-        struct utmpx lookup, *found;
+        struct utmpx *found, lookup = { .ut_type = RUN_LVL };
         int r;
         const char *e;
 
@@ -46,13 +45,15 @@ int utmp_get_runlevel(int *runlevel, int *previous) {
          * very new and does not apply to the current script being
          * executed. */
 
-        if ((e = getenv("RUNLEVEL")) && e[0] > 0) {
+        e = getenv("RUNLEVEL");
+        if (e && e[0] > 0) {
                 *runlevel = e[0];
 
                 if (previous) {
                         /* $PREVLEVEL seems to be an Upstart thing */
 
-                        if ((e = getenv("PREVLEVEL")) && e[0] > 0)
+                        e = getenv("PREVLEVEL");
+                        if (e && e[0] > 0)
                                 *previous = e[0];
                         else
                                 *previous = 0;
@@ -66,10 +67,8 @@ int utmp_get_runlevel(int *runlevel, int *previous) {
 
         setutxent();
 
-        zero(lookup);
-        lookup.ut_type = RUN_LVL;
-
-        if (!(found = getutxid(&lookup)))
+        found = getutxid(&lookup);
+        if (!found)
                 r = -errno;
         else {
                 int a, b;
@@ -77,15 +76,11 @@ int utmp_get_runlevel(int *runlevel, int *previous) {
                 a = found->ut_pid & 0xFF;
                 b = (found->ut_pid >> 8) & 0xFF;
 
-                if (a < 0 || b < 0)
-                        r = -EIO;
-                else {
-                        *runlevel = a;
+                *runlevel = a;
+                if (previous)
+                        *previous = b;
 
-                        if (previous)
-                                *previous = b;
-                        r = 0;
-                }
+                r = 0;
         }
 
         endutxent();
@@ -96,8 +91,6 @@ int utmp_get_runlevel(int *runlevel, int *previous) {
 static void init_timestamp(struct utmpx *store, usec_t t) {
         assert(store);
 
-        zero(*store);
-
         if (t <= 0)
                 t = now(CLOCK_REALTIME);
 
@@ -106,14 +99,12 @@ static void init_timestamp(struct utmpx *store, usec_t t) {
 }
 
 static void init_entry(struct utmpx *store, usec_t t) {
-        struct utsname uts;
+        struct utsname uts = {};
 
         assert(store);
 
         init_timestamp(store, t);
 
-        zero(uts);
-
         if (uname(&uts) >= 0)
                 strncpy(store->ut_host, uts.release, sizeof(store->ut_host));
 
@@ -149,7 +140,7 @@ static int write_entry_wtmp(const struct utmpx *store) {
         assert(store);
 
         /* wtmp is a simple append-only file where each entry is
-        simply appended to * the end; i.e. basically a log. */
+        simply appended to the end; i.e. basically a log. */
 
         errno = 0;
         updwtmpx(_PATH_WTMPX, store);
@@ -178,7 +169,7 @@ static int write_entry_both(const struct utmpx *store) {
 }
 
 int utmp_put_shutdown(void) {
-        struct utmpx store;
+        struct utmpx store = {};
 
         init_entry(&store, 0);
 
@@ -189,7 +180,7 @@ int utmp_put_shutdown(void) {
 }
 
 int utmp_put_reboot(usec_t t) {
-        struct utmpx store;
+        struct utmpx store = {};
 
         init_entry(&store, t);
 
@@ -199,7 +190,7 @@ int utmp_put_reboot(usec_t t) {
         return write_entry_both(&store);
 }
 
-static const char *sanitize_id(const char *id) {
+_pure_ static const char *sanitize_id(const char *id) {
         size_t l;
 
         assert(id);
@@ -212,36 +203,39 @@ static const char *sanitize_id(const char *id) {
 }
 
 int utmp_put_init_process(const char *id, pid_t pid, pid_t sid, const char *line) {
-        struct utmpx store;
+        struct utmpx store = {
+                .ut_type = INIT_PROCESS,
+                .ut_pid = pid,
+                .ut_session = sid,
+        };
 
         assert(id);
 
         init_timestamp(&store, 0);
 
-        store.ut_type = INIT_PROCESS;
-        store.ut_pid = pid;
-        store.ut_session = sid;
-
+        /* ut_id needs only be nul-terminated if it is shorter than sizeof(ut_id) */
         strncpy(store.ut_id, sanitize_id(id), sizeof(store.ut_id));
 
         if (line)
-                strncpy(store.ut_line, path_get_file_name(line), sizeof(store.ut_line));
+                strncpy(store.ut_line, basename(line), sizeof(store.ut_line));
 
         return write_entry_both(&store);
 }
 
 int utmp_put_dead_process(const char *id, pid_t pid, int code, int status) {
-        struct utmpx lookup, store, store_wtmp, *found;
+        struct utmpx lookup = {
+                .ut_type = INIT_PROCESS /* looks for DEAD_PROCESS, LOGIN_PROCESS, USER_PROCESS, too */
+        }, store, store_wtmp, *found;
 
         assert(id);
 
         setutxent();
 
-        zero(lookup);
-        lookup.ut_type = INIT_PROCESS; /* looks for DEAD_PROCESS, LOGIN_PROCESS, USER_PROCESS, too */
+        /* ut_id needs only be nul-terminated if it is shorter than sizeof(ut_id) */
         strncpy(lookup.ut_id, sanitize_id(id), sizeof(lookup.ut_id));
 
-        if (!(found = getutxid(&lookup)))
+        found = getutxid(&lookup);
+        if (!found)
                 return 0;
 
         if (found->ut_pid != pid)
@@ -265,7 +259,7 @@ int utmp_put_dead_process(const char *id, pid_t pid, int code, int status) {
 
 
 int utmp_put_runlevel(int runlevel, int previous) {
-        struct utmpx store;
+        struct utmpx store = {};
         int r;
 
         assert(runlevel > 0);
@@ -273,7 +267,8 @@ int utmp_put_runlevel(int runlevel, int previous) {
         if (previous <= 0) {
                 /* Find the old runlevel automatically */
 
-                if ((r = utmp_get_runlevel(&previous, NULL)) < 0) {
+                r = utmp_get_runlevel(&previous, NULL);
+                if (r < 0) {
                         if (r != -ESRCH)
                                 return r;
 
@@ -296,7 +291,7 @@ int utmp_put_runlevel(int runlevel, int previous) {
 #define TIMEOUT_MSEC 50
 
 static int write_to_terminal(const char *tty, const char *message) {
-        int fd, r;
+        _cleanup_close_ int fd = -1;
         const char *p;
         size_t left;
         usec_t end;
@@ -304,14 +299,10 @@ static int write_to_terminal(const char *tty, const char *message) {
         assert(tty);
         assert(message);
 
-        if ((fd = open(tty, O_WRONLY|O_NDELAY|O_NOCTTY|O_CLOEXEC)) < 0)
+        fd = open(tty, O_WRONLY|O_NDELAY|O_NOCTTY|O_CLOEXEC);
+        if (fd < 0 || !isatty(fd))
                 return -errno;
 
-        if (!isatty(fd)) {
-                r = -errno;
-                goto finish;
-        }
-
         p = message;
         left = strlen(message);
 
@@ -319,36 +310,31 @@ static int write_to_terminal(const char *tty, const char *message) {
 
         while (left > 0) {
                 ssize_t n;
-                struct pollfd pollfd;
+                struct pollfd pollfd = {
+                        .fd = fd,
+                        .events = POLLOUT,
+                };
                 usec_t t;
                 int k;
 
                 t = now(CLOCK_MONOTONIC);
 
-                if (t >= end) {
-                        r = -ETIME;
-                        goto finish;
-                }
+                if (t >= end)
+                        return -ETIME;
 
-                zero(pollfd);
-                pollfd.fd = fd;
-                pollfd.events = POLLOUT;
-
-                if ((k = poll(&pollfd, 1, (end - t) / USEC_PER_MSEC)) < 0)
+                k = poll(&pollfd, 1, (end - t) / USEC_PER_MSEC);
+                if (k < 0)
                         return -errno;
 
-                if (k <= 0) {
-                        r = -ETIME;
-                        goto finish;
-                }
-
-                if ((n = write(fd, p, left)) < 0) {
+                if (k == 0)
+                        return -ETIME;
 
+                n = write(fd, p, left);
+                if (n < 0) {
                         if (errno == EAGAIN)
                                 continue;
 
-                        r = -errno;
-                        goto finish;
+                        return -errno;
                 }
 
                 assert((size_t) n <= left);
@@ -357,24 +343,22 @@ static int write_to_terminal(const char *tty, const char *message) {
                 left -= n;
         }
 
-        r = 0;
-
-finish:
-        close_nointr_nofail(fd);
-
-        return r;
+        return 0;
 }
 
-int utmp_wall(const char *message, bool (*match_tty)(const char *tty)) {
-        struct utmpx *u;
+int utmp_wall(const char *message, const char *username, bool (*match_tty)(const char *tty)) {
+        _cleanup_free_ char *text = NULL, *hn = NULL, *un = NULL, *tty = NULL;
         char date[FORMAT_TIMESTAMP_MAX];
-        char *text = NULL, *hn = NULL, *un = NULL, *tty = NULL;
+        struct utmpx *u;
         int r;
 
-        if (!(hn = gethostname_malloc()) ||
-            !(un = getlogname_malloc())) {
-                r = -ENOMEM;
-                goto finish;
+        hn = gethostname_malloc();
+        if (!hn)
+                return -ENOMEM;
+        if (!username) {
+                un = getlogname_malloc();
+                if (!un)
+                        return -ENOMEM;
         }
 
         getttyname_harder(STDIN_FILENO, &tty);
@@ -383,22 +367,20 @@ int utmp_wall(const char *message, bool (*match_tty)(const char *tty)) {
                      "\a\r\n"
                      "Broadcast message from %s@%s%s%s (%s):\r\n\r\n"
                      "%s\r\n\r\n",
-                     un, hn,
+                     un ?: username, hn,
                      tty ? " on " : "", strempty(tty),
                      format_timestamp(date, sizeof(date), now(CLOCK_REALTIME)),
-                     message) < 0) {
-                r = -ENOMEM;
-                goto finish;
-        }
+                     message) < 0)
+                return -ENOMEM;
 
         setutxent();
 
         r = 0;
 
         while ((u = getutxent())) {
-                int q;
+                _cleanup_free_ char *buf = NULL;
                 const char *path;
-                char *buf = NULL;
+                int q;
 
                 if (u->ut_type != USER_PROCESS || u->ut_user[0] == 0)
                         continue;
@@ -407,27 +389,18 @@ int utmp_wall(const char *message, bool (*match_tty)(const char *tty)) {
                 if (path_startswith(u->ut_line, "/dev/"))
                         path = u->ut_line;
                 else {
-                        if (asprintf(&buf, "/dev/%.*s",
-                                     (int) sizeof(u->ut_line), u->ut_line) < 0) {
-                                r = -ENOMEM;
-                                goto finish;
-                        }
+                        if (asprintf(&buf, "/dev/%.*s", (int) sizeof(u->ut_line), u->ut_line) < 0)
+                                return -ENOMEM;
 
                         path = buf;
                 }
 
-                if (!match_tty || match_tty(path))
-                        if ((q = write_to_terminal(path, text)) < 0)
+                if (!match_tty || match_tty(path)) {
+                        q = write_to_terminal(path, text);
+                        if (q < 0)
                                 r = q;
-
-                free(buf);
+                }
         }
 
-finish:
-        free(hn);
-        free(un);
-        free(tty);
-        free(text);
-
         return r;
 }