* [Qemu-devel] [PATCH] readconfig: add emulation of /dev/fd/ to platforms that that lacks this API @ 2012-03-03 7:57 Ronnie Sahlberg 2012-03-03 7:57 ` [Qemu-devel] [PATCH] READCONFIG: allow /dev/fd/ the file to use for --readconfig Ronnie Sahlberg 0 siblings, 1 reply; 5+ messages in thread From: Ronnie Sahlberg @ 2012-03-03 7:57 UTC (permalink / raw) To: qemu-devel, kwolf Resending the patch with the strncmp() bug fixed. Its been a long long week when you mess up something as simple as this. regards ronnie sahlberg ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Qemu-devel] [PATCH] READCONFIG: allow /dev/fd/ the file to use for --readconfig 2012-03-03 7:57 [Qemu-devel] [PATCH] readconfig: add emulation of /dev/fd/ to platforms that that lacks this API Ronnie Sahlberg @ 2012-03-03 7:57 ` Ronnie Sahlberg 0 siblings, 0 replies; 5+ messages in thread From: Ronnie Sahlberg @ 2012-03-03 7:57 UTC (permalink / raw) To: qemu-devel, kwolf; +Cc: Ronnie Sahlberg On many platforms /dev/fd/<n> is used to refer to open filedescriptor <n> of the running process. If we fail to open the provided filename and if the filename starts with '/dev/fd/' then assume this is a platform which do not support these special files. In that case read out the descriptor value from the provided string and fdopen it. This allows to use /dev/fd/<n> syntax on all platforms, those that do provide this indeface in /dev and an emulation of this for the platforms that do not provide /dev/fd Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com> --- qemu-config.c | 16 +++++++++++++++- qemu-options.hx | 3 ++- 2 files changed, 17 insertions(+), 2 deletions(-) diff --git a/qemu-config.c b/qemu-config.c index 7d9da78..96e7497 100644 --- a/qemu-config.c +++ b/qemu-config.c @@ -814,9 +814,23 @@ out: int qemu_read_config_file(const char *filename) { - FILE *f = fopen(filename, "r"); + FILE *f; int ret; + f = fopen(filename, "r"); + + if (f == NULL && !strncmp(filename, "/dev/fd/", 8)) { + int fd; + char *ptr = NULL; + + errno = 0; + fd = strtol(filename + 8, &ptr, 10); + if (errno != 0 || ptr == filename + 8 || *ptr != '\0') { + return -EINVAL; + } + f = fdopen(fd, "r"); + } + if (f == NULL) { return -errno; } diff --git a/qemu-options.hx b/qemu-options.hx index b129996..c70c6e7 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -2650,7 +2650,8 @@ DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, STEXI @item -readconfig @var{file} @findex -readconfig -Read device configuration from @var{file}. +Read device configuration from @var{file}. Use '/dev/fd/<n>' as filename +to read from an existing, inherited, filedesriptor. ETEXI DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig, "-writeconfig <file>\n" -- 1.7.3.1 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* [Qemu-devel] [PATCH] readconfig: add emulation of /dev/fd/ to platforms that that lacks this API @ 2012-03-03 7:49 Ronnie Sahlberg 2012-03-19 16:43 ` Anthony Liguori 0 siblings, 1 reply; 5+ messages in thread From: Ronnie Sahlberg @ 2012-03-03 7:49 UTC (permalink / raw) To: qemu-devel, kwolf Please find a patch to -readconfig. On many platforms -readconfig /dev/fd/<n> can be used to read from an already opened and inherited filedescriptor <n>. On platforms that do not natively provide /dev/fd/<n> add emulation of this by checking if the ofiginal fopen(path) failed, then IF the path starts with /dev/fd/ then try to read the descriptorvalue and fdopen() it. It means that we can use -readconfig /dev/fd/<n> on all platforms. On those that provide a /dev/fd we just open that file. On those that do not we emulate it. regards ronnie sahlberg ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH] readconfig: add emulation of /dev/fd/ to platforms that that lacks this API 2012-03-03 7:49 [Qemu-devel] [PATCH] readconfig: add emulation of /dev/fd/ to platforms that that lacks this API Ronnie Sahlberg @ 2012-03-19 16:43 ` Anthony Liguori 2012-03-20 8:02 ` ronnie sahlberg 0 siblings, 1 reply; 5+ messages in thread From: Anthony Liguori @ 2012-03-19 16:43 UTC (permalink / raw) To: Ronnie Sahlberg; +Cc: kwolf, qemu-devel On 03/03/2012 01:49 AM, Ronnie Sahlberg wrote: > Please find a patch to -readconfig. > > On many platforms -readconfig /dev/fd/<n> can be used to read from an already opened and inherited filedescriptor<n>. > > On platforms that do not natively provide /dev/fd/<n> What platforms don't provide /dev/fd/<n> where fd passing makes sense? Regards, Anthony Liguori > add emulation of this by checking if the ofiginal fopen(path) failed, then IF > the path starts with /dev/fd/ then try to read the descriptorvalue and fdopen() it. > > > It means that we can use -readconfig /dev/fd/<n> on all platforms. On those that provide a /dev/fd we just open that file. On those that do not we emulate it. > > > regards > ronnie sahlberg > > ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH] readconfig: add emulation of /dev/fd/ to platforms that that lacks this API 2012-03-19 16:43 ` Anthony Liguori @ 2012-03-20 8:02 ` ronnie sahlberg 0 siblings, 0 replies; 5+ messages in thread From: ronnie sahlberg @ 2012-03-20 8:02 UTC (permalink / raw) To: Anthony Liguori; +Cc: kwolf, qemu-devel None. No platforms that I care about. On Tue, Mar 20, 2012 at 3:43 AM, Anthony Liguori <anthony@codemonkey.ws> wrote: > On 03/03/2012 01:49 AM, Ronnie Sahlberg wrote: >> >> Please find a patch to -readconfig. >> >> On many platforms -readconfig /dev/fd/<n> can be used to read from an >> already opened and inherited filedescriptor<n>. >> >> On platforms that do not natively provide /dev/fd/<n> > > > What platforms don't provide /dev/fd/<n> where fd passing makes sense? > > Regards, > > Anthony Liguori > > >> add emulation of this by checking if the ofiginal fopen(path) failed, then >> IF >> the path starts with /dev/fd/ then try to read the descriptorvalue and >> fdopen() it. >> >> >> It means that we can use -readconfig /dev/fd/<n> on all platforms. On >> those that provide a /dev/fd we just open that file. On those that do not we >> emulate it. >> >> >> regards >> ronnie sahlberg >> >> > ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2012-03-20 8:02 UTC | newest] Thread overview: 5+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2012-03-03 7:57 [Qemu-devel] [PATCH] readconfig: add emulation of /dev/fd/ to platforms that that lacks this API Ronnie Sahlberg 2012-03-03 7:57 ` [Qemu-devel] [PATCH] READCONFIG: allow /dev/fd/ the file to use for --readconfig Ronnie Sahlberg -- strict thread matches above, loose matches on Subject: below -- 2012-03-03 7:49 [Qemu-devel] [PATCH] readconfig: add emulation of /dev/fd/ to platforms that that lacks this API Ronnie Sahlberg 2012-03-19 16:43 ` Anthony Liguori 2012-03-20 8:02 ` ronnie sahlberg
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