6 files changed, 84 insertions, 39 deletions

diff --git a/libbb/appletlib.c b/libbb/appletlib.c
index 3f51ecef6..683d10b20 100644
--- a/libbb/appletlib.c
+++ b/libbb/appletlib.c
@@ -635,7 +635,7 @@ static int busybox_main(char **argv)
                 full_write2_str(bb_banner); /* reuse const string */
                 full_write2_str(" multi-call binary.\n"); /* reuse */
                 full_write2_str(
-                        "BusyBox is copyrighted by many authors between 1998-2012.\n"
+                        "BusyBox is copyrighted by many authors between 1998-2015.\n"
                         "Licensed under GPLv2. See source distribution for detailed\n"
                         "copyright notices.\n"
                         "\n"
@@ -761,23 +761,25 @@ void FAST_FUNC run_applet_no_and_exit(int applet_no, char **argv)
         xfunc_error_retval = EXIT_FAILURE;
         applet_name = APPLET_NAME(applet_no);
 
-#if defined APPLET_NO_test
         /* Special case. POSIX says "test --help"
          * should be no different from e.g. "test --foo".
          * Thus for "test", we skip --help check.
+         * "true" and "false" are also special.
          */
-        if (applet_no != APPLET_NO_test)
+        if (1
+#if defined APPLET_NO_test
+         && applet_no != APPLET_NO_test
+#endif
+#if defined APPLET_NO_true
+         && applet_no != APPLET_NO_true
 #endif
-        {
-                if (argc == 2 && strcmp(argv[1], "--help") == 0) {
 #if defined APPLET_NO_false
-                        /* Someone insisted that "false --help" must exit 1. Sigh */
-                        if (applet_no != APPLET_NO_false)
+         && applet_no != APPLET_NO_false
 #endif
-                        {
-                                /* Make "foo --help" exit with 0: */
-                                xfunc_error_retval = 0;
-                        }
+        ) {
+                if (argc == 2 && strcmp(argv[1], "--help") == 0) {
+                        /* Make "foo --help" exit with 0: */
+                        xfunc_error_retval = 0;
                         bb_show_usage();
                 }
         }
diff --git a/libbb/change_identity.c b/libbb/change_identity.c
index 619db09a8..d48d86326 100644
--- a/libbb/change_identity.c
+++ b/libbb/change_identity.c
@@ -33,9 +33,28 @@
 /* Become the user and group(s) specified by PW.  */
 void FAST_FUNC change_identity(const struct passwd *pw)
 {
-        if (initgroups(pw->pw_name, pw->pw_gid) == -1)
-                bb_perror_msg_and_die("can't set groups");
+        int res;
+
+        res = initgroups(pw->pw_name, pw->pw_gid);
         endgrent(); /* helps to close a fd used internally by libc */
+
+        if (res != 0) {
+                /*
+                 * If initgroups() fails because a system call is unimplemented
+                 * then we are running on a Linux kernel compiled without multiuser
+                 * support (CONFIG_MULTIUSER is not defined).
+                 *
+                 * If we are running without multiuser support *and* the target uid
+                 * already matches the current uid then we can skip the change of
+                 * identity.
+                 */
+                if (errno == ENOSYS && pw->pw_uid == getuid()) {
+                        return;
+                }
+
+                bb_perror_msg_and_die("can't set groups");
+        }
+
         xsetgid(pw->pw_gid);
         xsetuid(pw->pw_uid);
 }
diff --git a/libbb/missing_syscalls.c b/libbb/missing_syscalls.c
index dd430e3e2..e3c1e924b 100644
--- a/libbb/missing_syscalls.c
+++ b/libbb/missing_syscalls.c
@@ -39,4 +39,9 @@ int pivot_root(const char *new_root, const char *put_old)
 {
         return syscall(__NR_pivot_root, new_root, put_old);
 }
+
+int tcdrain(int fd)
+{
+        return ioctl(fd, TCSBRK, 1);
+}
 #endif
diff --git a/libbb/platform.c b/libbb/platform.c
index 8d90ca4e9..03bbb798b 100644
--- a/libbb/platform.c
+++ b/libbb/platform.c
@@ -194,3 +194,22 @@ ssize_t FAST_FUNC getline(char **lineptr, size_t *n, FILE *stream)
         return len;
 }
 #endif
+
+#ifndef HAVE_TTYNAME_R
+int ttyname_r(int fd, char *buf, size_t buflen)
+{
+        int r;
+        char path[sizeof("/proc/self/fd/%d") + sizeof(int)*3];
+
+        if (!isatty(fd))
+                return errno == EINVAL ? ENOTTY : errno;
+        sprintf(path, "/proc/self/fd/%d", fd);
+        r = readlink(path, buf, buflen);
+        if (r < 0)
+                return errno;
+        if (r >= buflen)
+                return ERANGE;
+        buf[r] = '\0';
+        return 0;
+}
+#endif
diff --git a/libbb/read_printf.c b/libbb/read_printf.c
index ef4911cd5..e47ac7afe 100644
--- a/libbb/read_printf.c
+++ b/libbb/read_printf.c
@@ -45,20 +45,20 @@
  * which detects EAGAIN and uses poll() to wait on the fd.
  * Thankfully, poll() doesn't care about O_NONBLOCK flag.
  */
-ssize_t FAST_FUNC nonblock_immune_read(int fd, void *buf, size_t count, int loop_on_EINTR)
+ssize_t FAST_FUNC nonblock_immune_read(int fd, void *buf, size_t count)
 {
         struct pollfd pfd[1];
         ssize_t n;
 
         while (1) {
-                n = loop_on_EINTR ? safe_read(fd, buf, count) : read(fd, buf, count);
+                n = safe_read(fd, buf, count);
                 if (n >= 0 || errno != EAGAIN)
                         return n;
                 /* fd is in O_NONBLOCK mode. Wait using poll and repeat */
                 pfd[0].fd = fd;
                 pfd[0].events = POLLIN;
                 /* note: safe_poll pulls in printf */
-                loop_on_EINTR ? safe_poll(pfd, 1, -1) : poll(pfd, 1, -1);
+                safe_poll(pfd, 1, -1);
         }
 }
 
@@ -81,7 +81,7 @@ char* FAST_FUNC xmalloc_reads(int fd, size_t *maxsz_p)
                         p = buf + sz;
                         sz += 128;
                 }
-                if (nonblock_immune_read(fd, p, 1, /*loop_on_EINTR:*/ 1) != 1) {
+                if (nonblock_immune_read(fd, p, 1) != 1) {
                         /* EOF/error */
                         if (p == buf) { /* we read nothing */
                                 free(buf);
diff --git a/libbb/utmp.c b/libbb/utmp.c
index 8ad9ba27e..bd07670db 100644
--- a/libbb/utmp.c
+++ b/libbb/utmp.c
@@ -16,7 +16,7 @@ static void touch(const char *filename)
 
 void FAST_FUNC write_new_utmp(pid_t pid, int new_type, const char *tty_name, const char *username, const char *hostname)
 {
-        struct utmp utent;
+        struct utmpx utent;
         char *id;
         unsigned width;
 
@@ -45,17 +45,17 @@ void FAST_FUNC write_new_utmp(pid_t pid, int new_type, const char *tty_name, con
                 tty_name += 3;
         strncpy(id, tty_name, width);
 
-        touch(_PATH_UTMP);
-        //utmpname(_PATH_UTMP);
-        setutent();
+        touch(_PATH_UTMPX);
+        //utmpxname(_PATH_UTMPX);
+        setutxent();
         /* Append new one (hopefully, unless we collide on ut_id) */
-        pututline(&utent);
-        endutent();
+        pututxline(&utent);
+        endutxent();
 
 #if ENABLE_FEATURE_WTMP
         /* "man utmp" says wtmp file should *not* be created automagically */
         /*touch(bb_path_wtmp_file);*/
-        updwtmp(bb_path_wtmp_file, &utent);
+        updwtmpx(bb_path_wtmp_file, &utent);
 #endif
 }
 
@@ -64,17 +64,17 @@ void FAST_FUNC write_new_utmp(pid_t pid, int new_type, const char *tty_name, con
  */
 void FAST_FUNC update_utmp(pid_t pid, int new_type, const char *tty_name, const char *username, const char *hostname)
 {
-        struct utmp utent;
-        struct utmp *utp;
+        struct utmpx utent;
+        struct utmpx *utp;
 
-        touch(_PATH_UTMP);
-        //utmpname(_PATH_UTMP);
-        setutent();
+        touch(_PATH_UTMPX);
+        //utmpxname(_PATH_UTMPX);
+        setutxent();
 
         /* Did init/getty/telnetd/sshd/... create an entry for us?
          * It should be (new_type-1), but we'd also reuse
          * any other potentially stale xxx_PROCESS entry */
-        while ((utp = getutent()) != NULL) {
+        while ((utp = getutxent()) != NULL) {
                 if (utp->ut_pid == pid
                 // && ut->ut_line[0]
                  && utp->ut_id[0] /* must have nonzero id */
@@ -88,25 +88,25 @@ void FAST_FUNC update_utmp(pid_t pid, int new_type, const char *tty_name, const
                                 /* Stale record. Nuke hostname */
                                 memset(utp->ut_host, 0, sizeof(utp->ut_host));
                         }
-                        /* NB: pututline (see later) searches for matching utent
-                         * using getutid(utent) - we must not change ut_id
+                        /* NB: pututxline (see later) searches for matching utxent
+                         * using getutxid(utent) - we must not change ut_id
                          * if we want *exactly this* record to be overwritten!
                          */
                         break;
                 }
         }
-        //endutent(); - no need, pututline can deal with (and actually likes)
+        //endutxent(); - no need, pututxline can deal with (and actually likes)
         //the situation when utmp file is positioned on found record
 
         if (!utp) {
                 if (new_type != DEAD_PROCESS)
                         write_new_utmp(pid, new_type, tty_name, username, hostname);
                 else
-                        endutent();
+                        endutxent();
                 return;
         }
 
-        /* Make a copy. We can't use *utp, pututline's internal getutid
+        /* Make a copy. We can't use *utp, pututxline's internal getutxid
          * will overwrite it before it is used! */
         utent = *utp;
 
@@ -120,14 +120,14 @@ void FAST_FUNC update_utmp(pid_t pid, int new_type, const char *tty_name, const
         utent.ut_tv.tv_sec = time(NULL);
 
         /* Update, or append new one */
-        //setutent();
-        pututline(&utent);
-        endutent();
+        //setutxent();
+        pututxline(&utent);
+        endutxent();
 
 #if ENABLE_FEATURE_WTMP
         /* "man utmp" says wtmp file should *not* be created automagically */
         /*touch(bb_path_wtmp_file);*/
-        updwtmp(bb_path_wtmp_file, &utent);
+        updwtmpx(bb_path_wtmp_file, &utent);
 #endif
 }