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-rw-r--r--INSTALL2
-rw-r--r--doc/index.html5
-rw-r--r--doc/s6-uevent-listener.html42
-rw-r--r--doc/upgrade.html6
-rw-r--r--package/deps.mak1
-rw-r--r--package/info2
-rw-r--r--src/minutils/s6-uevent-listener.c75
7 files changed, 55 insertions, 78 deletions
diff --git a/INSTALL b/INSTALL
index 656bbc8..2b310a8 100644
--- a/INSTALL
+++ b/INSTALL
@@ -9,7 +9,7 @@ Build Instructions
- skalibs version 2.5.0.0 or later: http://skarnet.org/software/skalibs/
This software is Linux-specific. It will run on a Linux kernel,
-version 2.6.32 or later.
+version 3.5 or later.
* Standard usage
diff --git a/doc/index.html b/doc/index.html
index 6627d5b..2e7897d 100644
--- a/doc/index.html
+++ b/doc/index.html
@@ -30,7 +30,8 @@
<h3> Requirements </h3>
<ul>
- <li> A Linux-based system with a standard C development environment </li>
+ <li> A Linux-based system with a standard C development environment.
+The Linux kernel must be 3.5 or later. </li>
<li> GNU make, version 3.81 or later </li>
<li> <a href="http://skarnet.org/software/skalibs/">skalibs</a> version
2.5.0.0 or later. It's a build-time requirement. It's also a run-time
@@ -49,7 +50,7 @@ library. </li>
<ul>
<li> The current released version of s6-linux-utils is
-<a href="s6-linux-utils-2.3.0.0.tar.gz">2.3.0.0</a>. </li>
+<a href="s6-linux-utils-2.4.0.0.tar.gz">2.4.0.0</a>. </li>
<li> Alternatively, you can checkout a copy of the
<a href="http://git.skarnet.org/cgi-bin/cgit.cgi/s6-linux-utils/">s6-linux-utils
git repository</a>:
diff --git a/doc/s6-uevent-listener.html b/doc/s6-uevent-listener.html
index 4db31d8..b1908a1 100644
--- a/doc/s6-uevent-listener.html
+++ b/doc/s6-uevent-listener.html
@@ -19,27 +19,29 @@
<h1> The <tt>s6-uevent-listener</tt> program </h1>
<p>
-<tt>s6-uevent-listener</tt> spawns a long-lived helper program.
-It then listens to the netlink interface for uevents (also called
-"hotplug" or "udev" events), and passes those events to the
-helper program's standard input, using a simple format.
+<tt>s6-uevent-listener</tt> listens to the netlink interface for uevents
+(also called "hotplug" or "udev" events), and writes those uevents to
+its standard output, using a simple format.
</p>
<h2> Interface </h2>
<pre>
- s6-uevent-listener [ -v <em>verbosity</em> ] [ -b kbufsz ] <em>prog...</em>
+ s6-uevent-listener [ -v <em>verbosity</em> ] [ -b kbufsz ]
</pre>
<ul>
- <li> s6-uevent-listener spawns <em>prog...</em> with a pipe writing to
-<em>prog</em>' stdin. </li>
<li> s6-uevent-listener binds to the netlink interface and listens for
hotplug events, as the <em>udev</em> program does. </li>
- <li> It transmits event information to <em>prog</em> via the pipe. </li>
- <li> s6-uevent-listener, like <em>prog</em>, is a long-lived program.
+ <li> It writes event information to its stdout. The output contains
+null characters, so a terminal will not display them correctly. To
+properly use s6-uevent-listener, it should be piped into a handler
+program such as
+<a href="s6-uevent-spawner.html">s6-uevent-spawner</a> or
+<a href="mdevd.html">mdevd</a>. </li>
+ <li> s6-uevent-listener is a long-lived program.
When it receives a SIGTERM, it stops listening; it will
-exit as soon as it has flushed its event queue to <em>prog</em>. </li>
+exit as soon as it has flushed its event queue to stdout. </li>
</ul>
<h2> Options </h2>
@@ -58,8 +60,6 @@ the large side). </li>
<h2> Protocol </h2>
<ul>
- <li> <em>prog</em> should read a series of events on its stdin, and exit
-on EOF. </li>
<li> An event is a series of null-terminated strings as they are sent by
the kernel to the netlink; s6-uevent-listener adds a final empty string
(i.e. an additional null character) to mark the end of the series. </li>
@@ -90,11 +90,19 @@ as <a href="http://skarnet.org/software/s6/">s6</a>. </li>
<li> If you are running s6-uevent-listener, <em>prog...</em> should be the
only program handling uevents, which means that
<tt>/proc/sys/kernel/hotplug</tt> should be empty. </li>
- <li> If you want the serialization benefit of the netlink, but still
-want to spawn a program such as <a href="http://busybox.net/">busybox</a>'s
-or <a href="http://landley.net/toybox/">toybox</a>'s <tt>mdev</tt>, use
-<tt><a href="s6-uevent-spawner.html">s6-uevent-spawner</a> mdev</tt> as
-s6-uevent-listener's <em>prog</em>. </li>
+ <li> Examples of valid uses of s6-uevent-listener:
+ <ul>
+ <li> <tt>s6-uevent-listener | s6-uevent-spawner mdev</tt> </li>
+ <li> <tt>s6-uevent-listener | mdevd</tt> </li>
+ <li> Those examples can be made safer by using a supervision system:
+under <a href="http://skarnet.org/software/s6/">s6</a> or
+<a href="http://skarnet.org/software/s6-rc/">s6-rc</a>, write a service
+pipeline where <tt>s6-uevent-listener</tt> is a producer and
+<tt>s6-uevent-spawner mdev</tt> or <tt>mdevd</tt> is a consumer. This
+setup has the advantage, among others, that you can restart the netlink
+listener and the event handler separately. </li>
+ </ul>
+ </li>
</ul>
</body>
diff --git a/doc/upgrade.html b/doc/upgrade.html
index f5c14b0..91a143a 100644
--- a/doc/upgrade.html
+++ b/doc/upgrade.html
@@ -18,6 +18,12 @@
<h1> What has changed in s6-linux-utils </h1>
+<h2> in 2.4.0.0 </h2>
+
+<ul>
+ <li> Linux dependency bumped to 3.5. </li>
+</ul>
+
<h2> in 2.3.0.0 </h2>
<ul>
diff --git a/package/deps.mak b/package/deps.mak
index 74e1ff2..7aaf8d0 100644
--- a/package/deps.mak
+++ b/package/deps.mak
@@ -2,6 +2,7 @@
# This file has been generated by tools/gen-deps.sh
#
+src/minutils/mdevd.o src/minutils/mdevd.lo: src/minutils/mdevd.c
src/minutils/s6-chroot.o src/minutils/s6-chroot.lo: src/minutils/s6-chroot.c
src/minutils/s6-devd.o src/minutils/s6-devd.lo: src/minutils/s6-devd.c src/include/s6-linux-utils/config.h
src/minutils/s6-fillurandompool.o src/minutils/s6-fillurandompool.lo: src/minutils/s6-fillurandompool.c
diff --git a/package/info b/package/info
index f39d9e7..65df44f 100644
--- a/package/info
+++ b/package/info
@@ -1,4 +1,4 @@
package=s6-linux-utils
-version=2.3.0.0
+version=2.4.0.0
category=admin
package_macro_name=S6_LINUX_UTILS
diff --git a/src/minutils/s6-uevent-listener.c b/src/minutils/s6-uevent-listener.c
index 29fbc38..e882821 100644
--- a/src/minutils/s6-uevent-listener.c
+++ b/src/minutils/s6-uevent-listener.c
@@ -9,32 +9,28 @@
#include <errno.h>
#include <signal.h>
#include <sys/socket.h>
-#include <sys/wait.h>
#include <linux/netlink.h>
#include <skalibs/types.h>
#include <skalibs/allreadwrite.h>
#include <skalibs/siovec.h>
#include <skalibs/buffer.h>
#include <skalibs/sgetopt.h>
+#include <skalibs/error.h>
#include <skalibs/strerr2.h>
#include <skalibs/iopause.h>
#include <skalibs/djbunix.h>
#include <skalibs/sig.h>
#include <skalibs/selfpipe.h>
-#define USAGE "s6-uevent-listener [ -v verbosity ] [ -b kbufsz ] helperprogram..."
+#define USAGE "s6-uevent-listener [ -v verbosity ] [ -b kbufsz ]"
#define dieusage() strerr_dieusage(100, USAGE)
#define dienomem() strerr_diefu1sys(111, "build string") ;
#define MAXNLSIZE 4096
-#define BUFSIZE 8191
-static char buf1[BUFSIZE + 1] ;
-static buffer b1 = BUFFER_INIT(&buffer_write, 1, buf1, BUFSIZE + 1) ;
static unsigned int cont = 1, verbosity = 1 ;
-static pid_t pid ;
-static inline int fd_recvmsg (int fd, struct msghdr *hdr)
+static inline ssize_t fd_recvmsg (int fd, struct msghdr *hdr)
{
ssize_t r ;
do r = recvmsg(fd, hdr, MSG_DONTWAIT) ;
@@ -64,26 +60,6 @@ static inline void handle_signals (void)
cont = 0 ;
fd_close(0) ;
break ;
- case SIGCHLD :
- {
- char fmt[UINT_FMT] ;
- int wstat ;
- int r = wait_pid_nohang(pid, &wstat) ;
- if (r < 0)
- if (errno != ECHILD) strerr_diefu1sys(111, "wait_pid_nohang") ;
- else break ;
- else if (!r) break ;
- if (WIFSIGNALED(wstat))
- {
- fmt[uint_fmt(fmt, WTERMSIG(wstat))] = 0 ;
- strerr_dief2x(1, "child crashed with signal ", fmt) ;
- }
- else
- {
- fmt[uint_fmt(fmt, WEXITSTATUS(wstat))] = 0 ;
- strerr_dief2x(1, "child exited ", fmt) ;
- }
- }
default :
strerr_dief1x(101, "internal error: inconsistent signal state. Please submit a bug-report.") ;
}
@@ -92,7 +68,8 @@ static inline void handle_signals (void)
static inline void handle_stdout (void)
{
- if (!buffer_flush(&b1)) strerr_diefu1sys(111, "flush stdout") ;
+ if (!buffer_flush(buffer_1) && !error_isagain(errno))
+ strerr_diefu1sys(111, "flush stdout") ;
}
static inline void handle_netlink (void)
@@ -110,7 +87,7 @@ static inline void handle_netlink (void)
.msg_flags = 0
} ;
ssize_t r ;
- buffer_wpeek(&b1, v) ;
+ buffer_wpeek(buffer_1, v) ;
siovec_trunc(v, 2, siovec_len(v, 2) - 1) ;
r = sanitize_read(fd_recvmsg(0, &msg)) ;
if (r < 0)
@@ -131,14 +108,14 @@ static inline void handle_netlink (void)
{
if (verbosity >= 3)
{
- char fmt[UINT_FMT] ;
- fmt[uint_fmt(fmt, nl.nl_pid)] = 0 ;
+ char fmt[PID_FMT] ;
+ fmt[pid_fmt(fmt, nl.nl_pid)] = 0 ;
strerr_warnw3x("netlink message", " from userspace process ", fmt) ;
}
return ;
}
- buffer_wseek(&b1, r) ;
- buffer_putnoflush(&b1, "", 1) ;
+ buffer_wseek(buffer_1, r) ;
+ buffer_putnoflush(buffer_1, "", 1) ;
}
@@ -161,45 +138,29 @@ int main (int argc, char const *const *argv, char const *const *envp)
}
}
argc -= l.ind ; argv += l.ind ;
- if (!argc) strerr_dieusage(100, USAGE) ;
if (!netlink_init_stdin(kbufsz)) strerr_diefu1sys(111, "init netlink") ;
}
x[0].fd = selfpipe_init() ;
if (x[0].fd < 0) strerr_diefu1sys(111, "init selfpipe") ;
if (sig_ignore(SIGPIPE) < 0) strerr_diefu1sys(111, "ignore SIGPIPE") ;
- {
- sigset_t set ;
- sigemptyset(&set) ;
- sigaddset(&set, SIGTERM) ;
- sigaddset(&set, SIGCHLD) ;
- if (selfpipe_trapset(&set) < 0) strerr_diefu1sys(111, "trap signals") ;
- }
-
- {
- int fd ;
- pid = child_spawn1_pipe(argv[0], argv, envp, &fd, 0) ;
- if (!pid) strerr_diefu2sys(111, "spawn ", argv[0]) ;
- if (fd_move(1, fd) < 0) strerr_diefu1sys(111, "move pipe to stdout") ;
- if (ndelay_on(1) < 0) strerr_diefu1sys(111, "make stdout nonblocking") ;
- }
+ if (selfpipe_trap(SIGTERM) < 0) strerr_diefu1sys(111, "trap SIGTERM") ;
if (verbosity >= 2) strerr_warni1x("starting") ;
while (cont || buffer_len(buffer_1))
{
int r ;
- x[1].events = buffer_len(&b1) ? IOPAUSE_WRITE : 0 ;
- x[2].events = buffer_available(&b1) >= MAXNLSIZE + 1 ? IOPAUSE_READ : 0 ;
+ x[1].events = buffer_len(buffer_1) ? IOPAUSE_WRITE : 0 ;
+ x[2].events = buffer_available(buffer_1) >= MAXNLSIZE + 1 ? IOPAUSE_READ : 0 ;
r = iopause(x, 2 + cont, 0, 0) ;
if (r < 0) strerr_diefu1sys(111, "iopause") ;
if (!r) continue ;
- if (x[0].revents & IOPAUSE_EXCEPT)
- strerr_diefu1x(111, "iopause: trouble with selfpipe") ;
- if (x[0].revents & IOPAUSE_READ)
- handle_signals() ;
- if (x[1].revents & IOPAUSE_WRITE)
- handle_stdout() ;
+ for (r = 0 ; r < 2 ; r++)
+ if (x[r].revents & IOPAUSE_EXCEPT)
+ x[r].revents |= IOPAUSE_READ | IOPAUSE_WRITE ;
+ if (x[0].revents & IOPAUSE_READ) handle_signals() ;
+ if (x[1].revents & IOPAUSE_WRITE) handle_stdout() ;
if (cont && x[2].events & IOPAUSE_READ && x[2].revents & IOPAUSE_READ)
handle_netlink() ;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-25 06:46:59 +0000