[systemd-commits] 2 commits - man/tmpfiles.d.xml src/core src/tmpfiles

[Zbigniew Jędrzejewski-Szmek]

 man/tmpfiles.d.xml      |    5 ++++-
 src/core/socket.c       |    2 +-
 src/tmpfiles/tmpfiles.c |   22 +++++++---------------
 3 files changed, 12 insertions(+), 17 deletions(-)

New commits:
commit 54693d9bfa855841e8097d7a6b8c8d7acc068004
Author: Dave Reisner <dreisner at archlinux.org>
Date:   Sat Sep 15 12:58:49 2012 -0400

    tmpfiles: use write(2) for the 'w' action
    
    This resolves problems with filesystems which do not implement the
    aio_write file operation. In this case, the kernel will fall back using
    a loop writing technique for each pointer in a received iovec. The
    result is strange errors in dmesg such as:
    
    [   31.855871] elevator: type  not found
    [   31.856262] elevator: switch to
    [   31.856262]  failed
    
    It does not make sense to implement a synchronous aio_write method for
    sysfs as this isn't a real filesystem where a reasonable use case for
    using writev exists, nor is there an expectation that tmpfiles will be
    used to write more data than can be reasonably written in a single write
    syscall.
    
    In addition, some sysfs attrs are currently buggy and will NOT reject
    the second write with the newline, causing the sysfs value to be zeroed
    out. This of course should be fixed in the kernel regardless of any
    wrongdoing in userspace, but this simple change makes us immune to such
    a bug.
    
    This change means that we do not write a trailing newline by default, as
    the expected use case of 'w' is for sysfs and procfs. In exchange, honor
    C-style backslash escapes so that if the newline is really needed, the
    user can add it.

diff --git a/man/tmpfiles.d.xml b/man/tmpfiles.d.xml
index c6325a4..a86ef33 100644
--- a/man/tmpfiles.d.xml
+++ b/man/tmpfiles.d.xml
@@ -114,7 +114,10 @@ L    /tmp/foobar -    -    -    -   /dev/null</programlisting>
 
                                 <varlistentry>
                                         <term><varname>w</varname></term>
-                                        <listitem><para>Write the argument parameter to a file, if it exists. Lines of this type accept shell-style globs in place of normal path names.</para></listitem>
+                                        <listitem><para>Write the argument parameter to a file, if the file exists.
+                                            Lines of this type accept shell-style globs in place of normal path
+                                            names. The argument parameter will be written without a trailing
+                                            newline. C-style backslash escapes are interpreted.</para></listitem>
                                 </varlistentry>
 
                                 <varlistentry>
diff --git a/src/tmpfiles/tmpfiles.c b/src/tmpfiles/tmpfiles.c
index ed51ec8..5d0f571 100644
--- a/src/tmpfiles/tmpfiles.c
+++ b/src/tmpfiles/tmpfiles.c
@@ -42,6 +42,7 @@
 
 #include "log.h"
 #include "util.h"
+#include "macro.h"
 #include "mkdir.h"
 #include "path-util.h"
 #include "strv.h"
@@ -503,24 +504,15 @@ static int write_one_file(Item *i, const char *path) {
         if (i->argument) {
                 ssize_t n;
                 size_t l;
-                struct iovec iovec[2];
-                static const char new_line = '\n';
+                _cleanup_free_ char *unescaped;
 
-                l = strlen(i->argument);
+                unescaped = cunescape(i->argument);
+                if (unescaped == NULL)
+                        return log_oom();
 
-                zero(iovec);
-                iovec[0].iov_base = i->argument;
-                iovec[0].iov_len = l;
+                l = strlen(unescaped);
+                n = write(fd, unescaped, l);
 
-                iovec[1].iov_base = (void*) &new_line;
-                iovec[1].iov_len = 1;
-
-                n = writev(fd, iovec, 2);
-
-                /* It's OK if we don't write the trailing
-                 * newline, hence we check for l, instead of
-                 * l+1 here. Files in /sys often refuse
-                 * writing of the trailing newline. */
                 if (n < 0 || (size_t) n < l) {
                         log_error("Failed to write file %s: %s", path, n < 0 ? strerror(-n) : "Short write");
                         close_nointr_nofail(fd);

commit c65a0b146652cac52fe3c43f7cb8fe6a2ac3e063
Author: Dave Reisner <dreisner at archlinux.org>
Date:   Sat Sep 15 12:58:48 2012 -0400

    socket: prevent signed integer overflow
    
    src/core/socket.c:588:25: error: overflow in implicit constant conversion
    src/core/socket.c:589:17: error: overflow in implicit constant conversion

diff --git a/src/core/socket.c b/src/core/socket.c
index cbbfb0c..f975a43 100644
--- a/src/core/socket.c
+++ b/src/core/socket.c
@@ -584,7 +584,7 @@ static int instance_from_socket(int fd, unsigned nr, char **instance) {
         }
 
         case AF_INET6: {
-                static const char ipv4_prefix[] = {
+                static const unsigned char ipv4_prefix[] = {
                         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF
                 };