diff options
| -rw-r--r-- | ChangeLog | 12 | ||||
| -rw-r--r-- | lib/passfd.c | 49 | ||||
| -rw-r--r-- | lib/passfd.h | 2 | ||||
| -rw-r--r-- | m4/afunix.m4 | 29 | ||||
| -rw-r--r-- | modules/passfd | 1 |
5 files changed, 89 insertions, 4 deletions
@@ -1,3 +1,15 @@ +2011-03-13 Bastien Roucariès <roucaries.bastien@gmail.com> + Bruno Haible <bruno@clisp.org> + + passfd module, part 3. + * lib/passfd.h (recvfd): Add a flags argument. + * lib/passfd.c: Include <fcntl.h>, cloexec.h. + (recvfd): Add a flags argument. + * m4/afunix.m4 (gl_SOCKET_AFUNIX): Test whether MSG_CMSG_CLOEXEC + exists. + * modules/passfd (Depends-on): Add cloexec. + Suggested by Eric Blake. + 2011-03-13 Bruno Haible <bruno@clisp.org> passfd module, part 2, tweaks. diff --git a/lib/passfd.c b/lib/passfd.c index 127fc42cda..d694ba6e0c 100644 --- a/lib/passfd.c +++ b/lib/passfd.c @@ -19,6 +19,7 @@ #include "passfd.h" #include <errno.h> +#include <fcntl.h> #include <stddef.h> #include <stdlib.h> #include <string.h> @@ -30,6 +31,8 @@ # include <sys/un.h> #endif +#include "cloexec.h" + /* sendfd sends the file descriptor fd along the socket to a process calling recvfd on the other end. @@ -79,16 +82,23 @@ sendfd (int sock, int fd) } /* recvfd receives a file descriptor through the socket. + The flags are a bitmask, possibly including O_CLOEXEC (defined in <fcntl.h>). Return 0 on success, or -1 with errno set in case of error. */ int -recvfd (int sock) +recvfd (int sock, int flags) { char recv = 0; struct iovec iov[1]; struct msghdr msg; + if ((flags & ~O_CLOEXEC) != 0) + { + errno = EINVAL; + return -1; + } + /* send at least one char */ iov[0].iov_base = &recv; iov[0].iov_len = 1; @@ -103,6 +113,11 @@ recvfd (int sock) struct cmsghdr *cmsg; char buf[CMSG_SPACE (sizeof (fd))]; const int mone = -1; +# if HAVE_MSG_CMSG_CLOEXEC + int flags_recvmsg = (flags & O_CLOEXEC ? MSG_CMSG_CLOEXEC : 0); +# else + int flags_recvmsg = 0; +# endif msg.msg_control = buf; msg.msg_controllen = sizeof (buf); @@ -114,7 +129,7 @@ recvfd (int sock) memcpy (CMSG_DATA (cmsg), &mone, sizeof (mone)); msg.msg_controllen = cmsg->cmsg_len; - if (recvmsg (sock, &msg, 0) < 0) + if (recvmsg (sock, &msg, flags_recvmsg) < 0) return -1; cmsg = CMSG_FIRSTHDR (&msg); @@ -128,7 +143,23 @@ recvfd (int sock) } memcpy (&fd, CMSG_DATA (cmsg), sizeof (fd)); + +# if !HAVE_MSG_CMSG_CLOEXEC + /* set close-on-exec flag */ + if (flags & O_CLOEXEC) + { + if (set_cloexec_flag (fd, true) < 0) + { + int saved_errno = errno; + (void) close (fd); + errno = saved_errno; + return -1; + } + } +# endif + return fd; + #elif HAVE_UNIXSOCKET_SCM_RIGHTS_BSD43_WAY int fd; @@ -136,7 +167,21 @@ recvfd (int sock) msg.msg_accrightslen = sizeof (fd); if (recvmsg (sock, &msg, 0) < 0) return -1; + + /* set close-on-exec flag */ + if (flags & O_CLOEXEC) + { + if (set_cloexec_flag (fd, true) < 0) + { + int saved_errno = errno; + (void) close (fd); + errno = saved_errno; + return -1; + } + } + return fd; + #else errno = ENOSYS; return -1; diff --git a/lib/passfd.h b/lib/passfd.h index 1fef2ddf23..048d9c8fc3 100644 --- a/lib/passfd.h +++ b/lib/passfd.h @@ -23,7 +23,7 @@ extern "C" { #endif extern int sendfd (int sock, int fd); -extern int recvfd (int sock); +extern int recvfd (int sock, int flags); #ifdef __cplusplus } diff --git a/m4/afunix.m4 b/m4/afunix.m4 index 8095ae921d..fdedeba673 100644 --- a/m4/afunix.m4 +++ b/m4/afunix.m4 @@ -1,4 +1,4 @@ -# afunix.m4 serial 2 +# afunix.m4 serial 3 dnl Copyright (C) 2011 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -109,4 +109,31 @@ AC_DEFUN([gl_SOCKET_AFUNIX], AC_DEFINE([HAVE_UNIXSOCKET_SCM_RIGHTS_BSD43_WAY], [1], [Define to 1 if fd can be sent/received in the BSD4.3 way.]) fi + + AC_MSG_CHECKING([for UNIX domain sockets recvmsg() MSG_CMSG_CLOEXEC flag]) + AC_CACHE_VAL([gl_cv_socket_unix_msg_cmsg_cloexec], + [AC_COMPILE_IFELSE( + [AC_LANG_PROGRAM( + [[#include <sys/types.h> + #ifdef HAVE_SYS_SOCKET_H + #include <sys/socket.h> + #endif + #ifdef HAVE_SYS_UN_H + #include <sys/un.h> + #endif + #ifdef HAVE_WINSOCK2_H + #include <winsock2.h> + #endif + ]], + [[int flags = MSG_CMSG_CLOEXEC; + if (&flags) return 0; + ]])], + [gl_cv_socket_unix_msg_cmsg_cloexec=yes], + [gl_cv_socket_unix_msg_cmsg_cloexec=no]) + ]) + AC_MSG_RESULT([$gl_cv_socket_unix_msg_cmsg_cloexec]) + if test $gl_cv_socket_unix_msg_cmsg_cloexec = yes; then + AC_DEFINE([HAVE_MSG_CMSG_CLOEXEC], [1], + [Define to 1 if recvmsg could be specified with MSG_CMSG_CLOEXEC.]) + fi ]) diff --git a/modules/passfd b/modules/passfd index dc1e68cf01..bdcd9c5c68 100644 --- a/modules/passfd +++ b/modules/passfd @@ -8,6 +8,7 @@ m4/afunix.m4 m4/sockpfaf.m4 Depends-on: +cloexec sys_socket extensions |