sysklogd: Support systemd socket-based activation

Syslogd cannot open /dev/log directly but must receive syslog messages
from systemd (http://www.freedesktop.org/wiki/Software/systemd/syslog).
The patch adds support for that.

3 files changed, 866 insertions, 14 deletions

diff --git a/pkgs/os-specific/linux/sysklogd/builder.sh b/pkgs/os-specific/linux/sysklogd/builder.sh
deleted file mode 100644
index d466f075652..00000000000
--- a/pkgs/os-specific/linux/sysklogd/builder.sh
+++ /dev/null
@@ -1,13 +0,0 @@
-source $stdenv/setup
-
-prefix=$out
-export prefix
-
-installFlags="BINDIR=$out/sbin MANDIR=$out/share/man INSTALL=install"
-patchPhase="sed -e 's@-o \${MAN_USER} -g \${MAN_GROUP} -m \${MAN_PERMS} @@' -i Makefile"
-
-mkdir -p "$out/share/man/man8/"
-mkdir -p "$out/share/man/man5/"
-mkdir -p "$out/sbin"
-
-genericBuild
diff --git a/pkgs/os-specific/linux/sysklogd/default.nix b/pkgs/os-specific/linux/sysklogd/default.nix
index 2fe27add5bf..979bfa1d0bf 100644
--- a/pkgs/os-specific/linux/sysklogd/default.nix
+++ b/pkgs/os-specific/linux/sysklogd/default.nix
@@ -2,9 +2,24 @@
 
 stdenv.mkDerivation {
   name = "sysklogd-1.5";
-  builder = ./builder.sh;
+
   src = fetchurl {
     url = http://www.infodrom.org/projects/sysklogd/download/sysklogd-1.5.tar.gz;
     sha256 = "0wxpkrznqwz4dy11k90s2sqszwp7d4mlc0ag8288wa193plvhsb1";
   };
+
+  patches = [ ./systemd.patch ];
+
+  installFlags = "BINDIR=$(out)/sbin MANDIR=$(out)/share/man INSTALL=install";
+
+  preConfigure =
+    ''
+      sed -e 's@-o \''${MAN_USER} -g \''${MAN_GROUP} -m \''${MAN_PERMS} @@' -i Makefile
+    '';
+
+  preInstall = "mkdir -p $out/share/man/man5/ $out/share/man/man8/ $out/sbin";
+
+  meta = {
+    description = "A system logging daemon";
+  };
 }
diff --git a/pkgs/os-specific/linux/sysklogd/systemd.patch b/pkgs/os-specific/linux/sysklogd/systemd.patch
new file mode 100644
index 00000000000..ecdf2b57ebf
--- /dev/null
+++ b/pkgs/os-specific/linux/sysklogd/systemd.patch
@@ -0,0 +1,850 @@
+Based on http://ftp.free.org/mirrors/rsync.frugalware.org/frugalware-testing/source/apps-extra/sysklogd/sysklogd-1.5-systemd.diff
+
+diff --git a/Makefile b/Makefile
+index 9a114b8..aef1fd6 100644
+--- a/Makefile
++++ b/Makefile
+@@ -20,7 +20,7 @@
+ CC= gcc
+ #SKFLAGS= -g -DSYSV -Wall
+ #LDFLAGS= -g
+-SKFLAGS= $(RPM_OPT_FLAGS) -O3 -DSYSV -fomit-frame-pointer -Wall -fno-strength-reduce
++SKFLAGS= $(RPM_OPT_FLAGS) -O3 -DSYSV -fomit-frame-pointer -Wall -fno-strength-reduce -I.
+ # -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE
+ # -D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE
+ # $(shell getconf LFS_SKFLAGS)
+@@ -79,8 +79,8 @@ test: syslog_tst ksym oops.ko tsyslogd
+ 
+ install: install_man install_exec
+ 
+-syslogd: syslogd.o pidfile.o
+-	${CC} ${LDFLAGS} -o syslogd syslogd.o pidfile.o ${LIBS}
++syslogd: syslogd.o pidfile.o sd-daemon.o
++	${CC} ${LDFLAGS} -o syslogd syslogd.o pidfile.o sd-daemon.o ${LIBS}
+ 
+ klogd:	klogd.o syslog.o pidfile.o ksym.o ksym_mod.o
+ 	${CC} ${LDFLAGS} -o klogd klogd.o syslog.o pidfile.o ksym.o \
+@@ -101,6 +101,9 @@ syslogd.o: syslogd.c version.h
+ syslog.o: syslog.c
+ 	${CC} ${SKFLAGS} ${SYSLOG_FLAGS} -c syslog.c
+ 
++sd-daemon.o: sd-daemon.c sd-daemon.h
++	${CC} ${SKFLAGS} ${SYSLOG_FLAGS} -c sd-daemon.c
++
+ klogd.o: klogd.c klogd.h version.h
+ 	${CC} ${SKFLAGS} ${KLOGD_FLAGS} $(DEB) -c klogd.c
+ 
+diff --git a/sd-daemon.c b/sd-daemon.c
+new file mode 100644
+index 0000000..6d1eebf
+--- /dev/null
++++ b/sd-daemon.c
+@@ -0,0 +1,436 @@
++/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
++
++/***
++  Copyright 2010 Lennart Poettering
++
++  Permission is hereby granted, free of charge, to any person
++  obtaining a copy of this software and associated documentation files
++  (the "Software"), to deal in the Software without restriction,
++  including without limitation the rights to use, copy, modify, merge,
++  publish, distribute, sublicense, and/or sell copies of the Software,
++  and to permit persons to whom the Software is furnished to do so,
++  subject to the following conditions:
++
++  The above copyright notice and this permission notice shall be
++  included in all copies or substantial portions of the Software.
++
++  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
++  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
++  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
++  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
++  BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
++  ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
++  CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
++  SOFTWARE.
++***/
++
++#ifndef _GNU_SOURCE
++#define _GNU_SOURCE
++#endif
++
++#include <sys/types.h>
++#include <sys/stat.h>
++#include <sys/socket.h>
++#include <sys/un.h>
++#include <sys/fcntl.h>
++#include <netinet/in.h>
++#include <stdlib.h>
++#include <errno.h>
++#include <unistd.h>
++#include <string.h>
++#include <stdarg.h>
++#include <stdio.h>
++#include <stddef.h>
++
++#include "sd-daemon.h"
++
++int sd_listen_fds(int unset_environment) {
++
++#if defined(DISABLE_SYSTEMD) || !defined(__linux__)
++        return 0;
++#else
++        int r, fd;
++        const char *e;
++        char *p = NULL;
++        unsigned long l;
++
++        if (!(e = getenv("LISTEN_PID"))) {
++                r = 0;
++                goto finish;
++        }
++
++        errno = 0;
++        l = strtoul(e, &p, 10);
++
++        if (errno != 0) {
++                r = -errno;
++                goto finish;
++        }
++
++        if (!p || *p || l <= 0) {
++                r = -EINVAL;
++                goto finish;
++        }
++
++        /* Is this for us? */
++        if (getpid() != (pid_t) l) {
++                r = 0;
++                goto finish;
++        }
++
++        if (!(e = getenv("LISTEN_FDS"))) {
++                r = 0;
++                goto finish;
++        }
++
++        errno = 0;
++        l = strtoul(e, &p, 10);
++
++        if (errno != 0) {
++                r = -errno;
++                goto finish;
++        }
++
++        if (!p || *p) {
++                r = -EINVAL;
++                goto finish;
++        }
++
++        for (fd = SD_LISTEN_FDS_START; fd < SD_LISTEN_FDS_START + (int) l; fd ++) {
++                int flags;
++
++                if ((flags = fcntl(fd, F_GETFD)) < 0) {
++                        r = -errno;
++                        goto finish;
++                }
++
++                if (flags & FD_CLOEXEC)
++                        continue;
++
++                if (fcntl(fd, F_SETFD, flags | FD_CLOEXEC) < 0) {
++                        r = -errno;
++                        goto finish;
++                }
++        }
++
++        r = (int) l;
++
++finish:
++        if (unset_environment) {
++                unsetenv("LISTEN_PID");
++                unsetenv("LISTEN_FDS");
++        }
++
++        return r;
++#endif
++}
++
++int sd_is_fifo(int fd, const char *path) {
++        struct stat st_fd;
++
++        if (fd < 0)
++                return -EINVAL;
++
++        memset(&st_fd, 0, sizeof(st_fd));
++        if (fstat(fd, &st_fd) < 0)
++                return -errno;
++
++        if (!S_ISFIFO(st_fd.st_mode))
++                return 0;
++
++        if (path) {
++                struct stat st_path;
++
++                memset(&st_path, 0, sizeof(st_path));
++                if (stat(path, &st_path) < 0) {
++
++                        if (errno == ENOENT || errno == ENOTDIR)
++                                return 0;
++
++                        return -errno;
++                }
++
++                return
++                        st_path.st_dev == st_fd.st_dev &&
++                        st_path.st_ino == st_fd.st_ino;
++        }
++
++        return 1;
++}
++
++static int sd_is_socket_internal(int fd, int type, int listening) {
++        struct stat st_fd;
++
++        if (fd < 0 || type < 0)
++                return -EINVAL;
++
++        if (fstat(fd, &st_fd) < 0)
++                return -errno;
++
++        if (!S_ISSOCK(st_fd.st_mode))
++                return 0;
++
++        if (type != 0) {
++                int other_type = 0;
++                socklen_t l = sizeof(other_type);
++
++                if (getsockopt(fd, SOL_SOCKET, SO_TYPE, &other_type, &l) < 0)
++                        return -errno;
++
++                if (l != sizeof(other_type))
++                        return -EINVAL;
++
++                if (other_type != type)
++                        return 0;
++        }
++
++        if (listening >= 0) {
++                int accepting = 0;
++                socklen_t l = sizeof(accepting);
++
++                if (getsockopt(fd, SOL_SOCKET, SO_ACCEPTCONN, &accepting, &l) < 0)
++                        return -errno;
++
++                if (l != sizeof(accepting))
++                        return -EINVAL;
++
++                if (!accepting != !listening)
++                        return 0;
++        }
++
++        return 1;
++}
++
++union sockaddr_union {
++        struct sockaddr sa;
++        struct sockaddr_in in4;
++        struct sockaddr_in6 in6;
++        struct sockaddr_un un;
++        struct sockaddr_storage storage;
++};
++
++int sd_is_socket(int fd, int family, int type, int listening) {
++        int r;
++
++        if (family < 0)
++                return -EINVAL;
++
++        if ((r = sd_is_socket_internal(fd, type, listening)) <= 0)
++                return r;
++
++        if (family > 0) {
++                union sockaddr_union sockaddr;
++                socklen_t l;
++
++                memset(&sockaddr, 0, sizeof(sockaddr));
++                l = sizeof(sockaddr);
++
++                if (getsockname(fd, &sockaddr.sa, &l) < 0)
++                        return -errno;
++
++                if (l < sizeof(sa_family_t))
++                        return -EINVAL;
++
++                return sockaddr.sa.sa_family == family;
++        }
++
++        return 1;
++}
++
++int sd_is_socket_inet(int fd, int family, int type, int listening, uint16_t port) {
++        union sockaddr_union sockaddr;
++        socklen_t l;
++        int r;
++
++        if (family != 0 && family != AF_INET && family != AF_INET6)
++                return -EINVAL;
++
++        if ((r = sd_is_socket_internal(fd, type, listening)) <= 0)
++                return r;
++
++        memset(&sockaddr, 0, sizeof(sockaddr));
++        l = sizeof(sockaddr);
++
++        if (getsockname(fd, &sockaddr.sa, &l) < 0)
++                return -errno;
++
++        if (l < sizeof(sa_family_t))
++                return -EINVAL;
++
++        if (sockaddr.sa.sa_family != AF_INET &&
++            sockaddr.sa.sa_family != AF_INET6)
++                return 0;
++
++        if (family > 0)
++                if (sockaddr.sa.sa_family != family)
++                        return 0;
++
++        if (port > 0) {
++                if (sockaddr.sa.sa_family == AF_INET) {
++                        if (l < sizeof(struct sockaddr_in))
++                                return -EINVAL;
++
++                        return htons(port) == sockaddr.in4.sin_port;
++                } else {
++                        if (l < sizeof(struct sockaddr_in6))
++                                return -EINVAL;
++
++                        return htons(port) == sockaddr.in6.sin6_port;
++                }
++        }
++
++        return 1;
++}
++
++int sd_is_socket_unix(int fd, int type, int listening, const char *path, size_t length) {
++        union sockaddr_union sockaddr;
++        socklen_t l;
++        int r;
++
++        if ((r = sd_is_socket_internal(fd, type, listening)) <= 0)
++                return r;
++
++        memset(&sockaddr, 0, sizeof(sockaddr));
++        l = sizeof(sockaddr);
++
++        if (getsockname(fd, &sockaddr.sa, &l) < 0)
++                return -errno;
++
++        if (l < sizeof(sa_family_t))
++                return -EINVAL;
++
++        if (sockaddr.sa.sa_family != AF_UNIX)
++                return 0;
++
++        if (path) {
++                if (length <= 0)
++                        length = strlen(path);
++
++                if (length <= 0)
++                        /* Unnamed socket */
++                        return l == offsetof(struct sockaddr_un, sun_path);
++
++                if (path[0])
++                        /* Normal path socket */
++                        return
++                                (l >= offsetof(struct sockaddr_un, sun_path) + length + 1) &&
++                                memcmp(path, sockaddr.un.sun_path, length+1) == 0;
++                else
++                        /* Abstract namespace socket */
++                        return
++                                (l == offsetof(struct sockaddr_un, sun_path) + length) &&
++                                memcmp(path, sockaddr.un.sun_path, length) == 0;
++        }
++
++        return 1;
++}
++
++int sd_notify(int unset_environment, const char *state) {
++#if defined(DISABLE_SYSTEMD) || !defined(__linux__) || !defined(SOCK_CLOEXEC)
++        return 0;
++#else
++        int fd = -1, r;
++        struct msghdr msghdr;
++        struct iovec iovec;
++        union sockaddr_union sockaddr;
++        const char *e;
++
++        if (!state) {
++                r = -EINVAL;
++                goto finish;
++        }
++
++        if (!(e = getenv("NOTIFY_SOCKET")))
++                return 0;
++
++        /* Must be an abstract socket, or an absolute path */
++        if ((e[0] != '@' && e[0] != '/') || e[1] == 0) {
++                r = -EINVAL;
++                goto finish;
++        }
++
++        if ((fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0)) < 0) {
++                r = -errno;
++                goto finish;
++        }
++
++        memset(&sockaddr, 0, sizeof(sockaddr));
++        sockaddr.sa.sa_family = AF_UNIX;
++        strncpy(sockaddr.un.sun_path, e, sizeof(sockaddr.un.sun_path));
++
++        if (sockaddr.un.sun_path[0] == '@')
++                sockaddr.un.sun_path[0] = 0;
++
++        memset(&iovec, 0, sizeof(iovec));
++        iovec.iov_base = (char*) state;
++        iovec.iov_len = strlen(state);
++
++        memset(&msghdr, 0, sizeof(msghdr));
++        msghdr.msg_name = &sockaddr;
++        msghdr.msg_namelen = offsetof(struct sockaddr_un, sun_path) + strlen(e);
++
++        if (msghdr.msg_namelen > sizeof(struct sockaddr_un))
++                msghdr.msg_namelen = sizeof(struct sockaddr_un);
++
++        msghdr.msg_iov = &iovec;
++        msghdr.msg_iovlen = 1;
++
++        if (sendmsg(fd, &msghdr, MSG_NOSIGNAL) < 0) {
++                r = -errno;
++                goto finish;
++        }
++
++        r = 1;
++
++finish:
++        if (unset_environment)
++                unsetenv("NOTIFY_SOCKET");
++
++        if (fd >= 0)
++                close(fd);
++
++        return r;
++#endif
++}
++
++int sd_notifyf(int unset_environment, const char *format, ...) {
++#if defined(DISABLE_SYSTEMD) || !defined(__linux__)
++        return 0;
++#else
++        va_list ap;
++        char *p = NULL;
++        int r;
++
++        va_start(ap, format);
++        r = vasprintf(&p, format, ap);
++        va_end(ap);
++
++        if (r < 0 || !p)
++                return -ENOMEM;
++
++        r = sd_notify(unset_environment, p);
++        free(p);
++
++        return r;
++#endif
++}
++
++int sd_booted(void) {
++#if defined(DISABLE_SYSTEMD) || !defined(__linux__)
++        return 0;
++#else
++
++        struct stat a, b;
++
++        /* We simply test whether the systemd cgroup hierarchy is
++         * mounted */
++
++        if (lstat("/sys/fs/cgroup", &a) < 0)
++                return 0;
++
++        if (lstat("/sys/fs/cgroup/systemd", &b) < 0)
++                return 0;
++
++        return a.st_dev != b.st_dev;
++#endif
++}
+diff --git a/sd-daemon.h b/sd-daemon.h
+new file mode 100644
+index 0000000..d0a0a94
+--- /dev/null
++++ b/sd-daemon.h
+@@ -0,0 +1,265 @@
++/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
++
++#ifndef foosddaemonhfoo
++#define foosddaemonhfoo
++
++/***
++  Copyright 2010 Lennart Poettering
++
++  Permission is hereby granted, free of charge, to any person
++  obtaining a copy of this software and associated documentation files
++  (the "Software"), to deal in the Software without restriction,
++  including without limitation the rights to use, copy, modify, merge,
++  publish, distribute, sublicense, and/or sell copies of the Software,
++  and to permit persons to whom the Software is furnished to do so,
++  subject to the following conditions:
++
++  The above copyright notice and this permission notice shall be
++  included in all copies or substantial portions of the Software.
++
++  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
++  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
++  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
++  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
++  BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
++  ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
++  CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
++  SOFTWARE.
++***/
++
++#include <sys/types.h>
++#include <inttypes.h>
++
++#ifdef __cplusplus
++extern "C" {
++#endif
++
++/*
++  Reference implementation of a few systemd related interfaces for
++  writing daemons. These interfaces are trivial to implement. To
++  simplify porting we provide this reference implementation.
++  Applications are welcome to reimplement the algorithms described
++  here if they do not want to include these two source files.
++
++  The following functionality is provided:
++
++  - Support for logging with log levels on stderr
++  - File descriptor passing for socket-based activation
++  - Daemon startup and status notification
++  - Detection of systemd boots
++
++  You may compile this with -DDISABLE_SYSTEMD to disable systemd
++  support. This makes all those calls NOPs that are directly related to
++  systemd (i.e. only sd_is_xxx() will stay useful).
++
++  Since this is drop-in code we don't want any of our symbols to be
++  exported in any case. Hence we declare hidden visibility for all of
++  them.
++
++  You may find an up-to-date version of these source files online:
++
++  http://cgit.freedesktop.org/systemd/plain/src/sd-daemon.h
++  http://cgit.freedesktop.org/systemd/plain/src/sd-daemon.c
++
++  This should compile on non-Linux systems, too, but with the
++  exception of the sd_is_xxx() calls all functions will become NOPs.
++
++  See sd-daemon(7) for more information.
++*/
++
++#ifndef _sd_printf_attr_
++#if __GNUC__ >= 4
++#define _sd_printf_attr_(a,b) __attribute__ ((format (printf, a, b)))
++#else
++#define _sd_printf_attr_(a,b)
++#endif
++#endif
++
++#ifndef _sd_hidden_
++#if (__GNUC__ >= 4) && !defined(SD_EXPORT_SYMBOLS)
++#define _sd_hidden_ __attribute__ ((visibility("hidden")))
++#else
++#define _sd_hidden_
++#endif
++#endif
++
++/*
++  Log levels for usage on stderr:
++
++          fprintf(stderr, SD_NOTICE "Hello World!\n");
++
++  This is similar to printk() usage in the kernel.
++*/
++#define SD_EMERG   "<0>"  /* system is unusable */
++#define SD_ALERT   "<1>"  /* action must be taken immediately */
++#define SD_CRIT    "<2>"  /* critical conditions */
++#define SD_ERR     "<3>"  /* error conditions */
++#define SD_WARNING "<4>"  /* warning conditions */
++#define SD_NOTICE  "<5>"  /* normal but significant condition */
++#define SD_INFO    "<6>"  /* informational */
++#define SD_DEBUG   "<7>"  /* debug-level messages */
++
++/* The first passed file descriptor is fd 3 */
++#define SD_LISTEN_FDS_START 3
++
++/*
++  Returns how many file descriptors have been passed, or a negative
++  errno code on failure. Optionally, removes the $LISTEN_FDS and
++  $LISTEN_PID file descriptors from the environment (recommended, but
++  problematic in threaded environments). If r is the return value of
++  this function you'll find the file descriptors passed as fds
++  SD_LISTEN_FDS_START to SD_LISTEN_FDS_START+r-1. Returns a negative
++  errno style error code on failure. This function call ensures that
++  the FD_CLOEXEC flag is set for the passed file descriptors, to make
++  sure they are not passed on to child processes. If FD_CLOEXEC shall
++  not be set, the caller needs to unset it after this call for all file
++  descriptors that are used.
++
++  See sd_listen_fds(3) for more information.
++*/
++int sd_listen_fds(int unset_environment) _sd_hidden_;
++
++/*
++  Helper call for identifying a passed file descriptor. Returns 1 if
++  the file descriptor is a FIFO in the file system stored under the
++  specified path, 0 otherwise. If path is NULL a path name check will
++  not be done and the call only verifies if the file descriptor
++  refers to a FIFO. Returns a negative errno style error code on
++  failure.
++
++  See sd_is_fifo(3) for more information.
++*/
++int sd_is_fifo(int fd, const char *path) _sd_hidden_;
++
++/*
++  Helper call for identifying a passed file descriptor. Returns 1 if
++  the file descriptor is a socket of the specified family (AF_INET,
++  ...) and type (SOCK_DGRAM, SOCK_STREAM, ...), 0 otherwise. If
++  family is 0 a socket family check will not be done. If type is 0 a
++  socket type check will not be done and the call only verifies if
++  the file descriptor refers to a socket. If listening is > 0 it is
++  verified that the socket is in listening mode. (i.e. listen() has
++  been called) If listening is == 0 it is verified that the socket is
++  not in listening mode. If listening is < 0 no listening mode check
++  is done. Returns a negative errno style error code on failure.
++
++  See sd_is_socket(3) for more information.
++*/
++int sd_is_socket(int fd, int family, int type, int listening) _sd_hidden_;
++
++/*
++  Helper call for identifying a passed file descriptor. Returns 1 if
++  the file descriptor is an Internet socket, of the specified family
++  (either AF_INET or AF_INET6) and the specified type (SOCK_DGRAM,
++  SOCK_STREAM, ...), 0 otherwise. If version is 0 a protocol version
++  check is not done. If type is 0 a socket type check will not be
++  done. If port is 0 a socket port check will not be done. The
++  listening flag is used the same way as in sd_is_socket(). Returns a
++  negative errno style error code on failure.
++
++  See sd_is_socket_inet(3) for more information.
++*/
++int sd_is_socket_inet(int fd, int family, int type, int listening, uint16_t port) _sd_hidden_;
++
++/*
++  Helper call for identifying a passed file descriptor. Returns 1 if
++  the file descriptor is an AF_UNIX socket of the specified type
++  (SOCK_DGRAM, SOCK_STREAM, ...) and path, 0 otherwise. If type is 0
++  a socket type check will not be done. If path is NULL a socket path
++  check will not be done. For normal AF_UNIX sockets set length to
++  0. For abstract namespace sockets set length to the length of the
++  socket name (including the initial 0 byte), and pass the full
++  socket path in path (including the initial 0 byte). The listening
++  flag is used the same way as in sd_is_socket(). Returns a negative
++  errno style error code on failure.
++
++  See sd_is_socket_unix(3) for more information.
++*/
++int sd_is_socket_unix(int fd, int type, int listening, const char *path, size_t length) _sd_hidden_;
++
++/*
++  Informs systemd about changed daemon state. This takes a number of
++  newline separated environment-style variable assignments in a
++  string. The following variables are known:
++
++     READY=1      Tells systemd that daemon startup is finished (only
++                  relevant for services of Type=notify). The passed
++                  argument is a boolean "1" or "0". Since there is
++                  little value in signalling non-readiness the only
++                  value daemons should send is "READY=1".
++
++     STATUS=...   Passes a single-line status string back to systemd
++                  that describes the daemon state. This is free-from
++                  and can be used for various purposes: general state
++                  feedback, fsck-like programs could pass completion
++                  percentages and failing programs could pass a human
++                  readable error message. Example: "STATUS=Completed
++                  66% of file system check..."
++
++     ERRNO=...    If a daemon fails, the errno-style error code,
++                  formatted as string. Example: "ERRNO=2" for ENOENT.
++
++     BUSERROR=... If a daemon fails, the D-Bus error-style error
++                  code. Example: "BUSERROR=org.freedesktop.DBus.Error.TimedOut"
++
++     MAINPID=...  The main pid of a daemon, in case systemd did not
++                  fork off the process itself. Example: "MAINPID=4711"
++
++  Daemons can choose to send additional variables. However, it is
++  recommened to prefix variable names not listed above with X_.
++
++  Returns a negative errno-style error code on failure. Returns > 0
++  if systemd could be notified, 0 if it couldn't possibly because
++  systemd is not running.
++
++  Example: When a daemon finished starting up, it could issue this
++  call to notify systemd about it:
++
++     sd_notify(0, "READY=1");
++
++  See sd_notifyf() for more complete examples.
++
++  See sd_notify(3) for more information.
++*/
++int sd_notify(int unset_environment, const char *state) _sd_hidden_;
++
++/*
++  Similar to sd_notify() but takes a format string.
++
++  Example 1: A daemon could send the following after initialization:
++
++     sd_notifyf(0, "READY=1\n"
++                   "STATUS=Processing requests...\n"
++                   "MAINPID=%lu",
++                   (unsigned long) getpid());
++
++  Example 2: A daemon could send the following shortly before
++  exiting, on failure:
++
++     sd_notifyf(0, "STATUS=Failed to start up: %s\n"
++                   "ERRNO=%i",
++                   strerror(errno),
++                   errno);
++
++  See sd_notifyf(3) for more information.
++*/
++int sd_notifyf(int unset_environment, const char *format, ...) _sd_printf_attr_(2,3) _sd_hidden_;
++
++/*
++  Returns > 0 if the system was booted with systemd. Returns < 0 on
++  error. Returns 0 if the system was not booted with systemd. Note
++  that all of the functions above handle non-systemd boots just
++  fine. You should NOT protect them with a call to this function. Also
++  note that this function checks whether the system, not the user
++  session is controlled by systemd. However the functions above work
++  for both user and system services.
++
++  See sd_booted(3) for more information.
++*/
++int sd_booted(void) _sd_hidden_;
++
++#ifdef __cplusplus
++}
++#endif
++
++#endif
+diff --git a/syslogd.c b/syslogd.c
+index acfd8f1..9bfa8c7 100644
+--- a/syslogd.c
++++ b/syslogd.c
+@@ -551,6 +551,7 @@ static char sccsid[] = "@(#)syslogd.c	5.27 (Berkeley) 10/10/88";
+ 
+ #if defined(__linux__)
+ #include <paths.h>
++#include <sd-daemon.h>
+ #endif
+ 
+ #ifndef UTMP_FILE
+@@ -965,8 +966,11 @@ int main(argc, argv)
+ 			}
+ 			signal (SIGTERM, SIG_DFL);
+ 			num_fds = getdtablesize();
+-			for (i= 0; i < num_fds; i++)
+-				(void) close(i);
++#if defined(__linux__)
++			if (sd_listen_fds(0) <= 0)
++#endif
++				for (i = 0; i < num_fds; i++)
++					(void) close(i);
+ 			untty();
+ 		}
+ 		else
+@@ -1253,6 +1257,60 @@ static int create_unix_socket(const char *path)
+ 	if (path[0] == '\0')
+ 		return -1;
+ 
++#if defined(__linux__)
++	if (strcmp(path, _PATH_LOG) == 0) {
++		int r;
++ 
++		/* Check whether an FD was passed in from systemd. If
++		 * so, it's the /dev/log socket, so use it. */
++ 
++		r = sd_listen_fds(0);
++		if (r < 0) {
++			logerror("Failed to acquire systemd socket");
++#ifndef SYSV
++			dienow();
++#else
++			return -1;
++#endif
++		}
++
++ 
++		if (r > 1) {
++			logerror("Wrong number of systemd sockets passed");
++#ifndef SYSV
++			dienow();
++#else
++			return -1;
++#endif
++		}
++ 
++		if (r == 1) {
++			fd = SD_LISTEN_FDS_START;
++			r = sd_is_socket_unix(fd, SOCK_DGRAM, -1, "/run/systemd/journal/syslog", 0);
++			if (r < 0) {
++				logerror("Failed to verify systemd socket type");
++#ifndef SYSV
++				dienow();
++#else
++				return -1;
++#endif
++			}
++ 
++			if (!r) {
++				logerror("Passed systemd socket of wrong type");
++#ifndef SYSV
++				dienow();
++#else
++				return -1;
++#endif
++			}
++ 
++		        dprintf("Using systemd socket (%d).\n", fd);
++			return fd;
++		}
++	}
++#endif
++
+ 	(void) unlink(path);
+ 
+ 	memset(&sunx, 0, sizeof(sunx));
+@@ -2254,7 +2311,12 @@ void die(sig)
+ 	if (InetInuse) close(inetm);
+ 
+ 	/* Clean-up files. */
+-        for (i = 0; i < nfunix; i++)
++	i = 0;
++#if defined(__linux__)
++	if (sd_listen_fds(0) > 0)
++		i = 1;
++#endif
++	for (; i < nfunix; i++)
+ 		if (funixn[i] && funix[i] != -1)
+ 			(void)unlink(funixn[i]);
+ #ifndef TESTING