From 1cde6c1b67cd2750ee47f01325271b4188c3d166 Mon Sep 17 00:00:00 2001 From: Yann Droneaud Date: Tue, 16 Jul 2013 23:59:52 +0200 Subject: [PATCH] [librdmacm,8/8] Open files with "close on exec" flag File opened by librdmacm are not supposed to be inherited across exec*(), most of the files are of no use for another program, and others cannot be used without the associated memory mapping. This patch changes fopen() open() and socket() to always set close on exec flag. This patch also add checks to configure to guess if fopen() supports "e" flag. If O_CLOEXEC and SOCK_CLOEXEC are supported, fopen() should support "e". If not supported, its discarded according to POSIX. Many operating systems have support for fopen("e"). You might find more information about close on exec in the following articles: - "Excuse me son, but your code is leaking !!!" by Dan Walsh http://danwalsh.livejournal.com/53603.html - "Secure File Descriptor Handling" by Ulrich Drepper http://udrepper.livejournal.com/20407.html Note: this patch won't set close on exec flag on file descriptors created by the kernel for completion channel and such. This is addressed by another kernel patch. Signed-off-by: Yann Droneaud Signed-off-by: Sean Hefty --- configure.ac | 24 ++++++++++++++++++++++++ src/acm.c | 4 ++-- src/cma.c | 2 +- 3 files changed, 27 insertions(+), 3 deletions(-) diff --git a/configure.ac b/configure.ac index 9fd9e9e6..6163f564 100644 --- a/configure.ac +++ b/configure.ac @@ -75,6 +75,30 @@ AC_CHECK_HEADER(infiniband/acm.h, AC_DEFINE(DEFINE_ACM_MSG, 1, [adding ACM message definition]), [#include ]), []) +dnl Checks close on exec support +AC_CHECK_HEADERS([fcntl.h sys/socket.h]) + +AC_CHECK_DECLS([O_CLOEXEC],,[AC_DEFINE([O_CLOEXEC],[0], [Defined to 0 if not provided])], +[[ +#ifdef HAVE_FCNTL_H +# include +#endif +]]) +AC_CHECK_DECLS([SOCK_CLOEXEC],,[AC_DEFINE([SOCK_CLOEXEC],[0],[Defined to 0 if not provided])], +[[ +#ifdef HAVE_SYS_SOCKET_H +# include +#endif +]]) + +AC_CACHE_CHECK(for close on exec modifier for fopen(), ac_cv_feature_stream_cloexec_flag, + [if test $ac_cv_have_decl_O_CLOEXEC = yes ; then + if test $ac_cv_have_decl_SOCK_CLOEXEC = yes ; then + ac_cv_feature_stream_cloexec_flag="e" + fi + fi]) +AC_DEFINE_UNQUOTED([STREAM_CLOEXEC], "$ac_cv_feature_stream_cloexec_flag", [fopen() modifier for setting close on exec flag]) + AC_CACHE_CHECK(whether ld accepts --version-script, ac_cv_version_script, if test -n "`$LD --help < /dev/null 2>/dev/null | grep version-script`"; then ac_cv_version_script=yes diff --git a/src/acm.c b/src/acm.c index c423bb72..dfc49599 100755 --- a/src/acm.c +++ b/src/acm.c @@ -79,7 +79,7 @@ static int ucma_set_server_port(void) { FILE *f; - if ((f = fopen("/var/run/ibacm.port", "r"))) { + if ((f = fopen("/var/run/ibacm.port", "r" STREAM_CLOEXEC))) { fscanf(f, "%hu", (unsigned short *) &server_port); fclose(f); } @@ -99,7 +99,7 @@ void ucma_ib_init(void) if (!ucma_set_server_port()) goto out; - sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); + sock = socket(AF_INET, SOCK_STREAM | SOCK_CLOEXEC, IPPROTO_TCP); if (sock < 0) goto out; diff --git a/src/cma.c b/src/cma.c index 2fb9913a..baebecdd 100755 --- a/src/cma.c +++ b/src/cma.c @@ -328,7 +328,7 @@ struct rdma_event_channel *rdma_create_event_channel(void) if (!channel) return NULL; - channel->fd = open("/dev/infiniband/rdma_cm", O_RDWR); + channel->fd = open("/dev/infiniband/rdma_cm", O_RDWR | O_CLOEXEC); if (channel->fd < 0) { fprintf(stderr, PFX "Fatal: unable to open /dev/infiniband/rdma_cm\n"); goto err; -- 2.41.0