diff options
Diffstat (limited to 'gnulib/lib/passfd.c')
| m--------- | gnulib | 0 | ||||
| -rw-r--r-- | gnulib/lib/passfd.c | 202 |
2 files changed, 202 insertions, 0 deletions
diff --git a/gnulib b/gnulib deleted file mode 160000 -Subproject 443bc5ffcf7429e557f4a371b0661abe98ddbc1 diff --git a/gnulib/lib/passfd.c b/gnulib/lib/passfd.c new file mode 100644 index 0000000..9458820 --- /dev/null +++ b/gnulib/lib/passfd.c @@ -0,0 +1,202 @@ +/* Copyright (C) 2011 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. */ + +#include <config.h> + +/* Specification. */ +#include "passfd.h" + +#include <errno.h> +#include <fcntl.h> +#include <stddef.h> +#include <stdlib.h> +#include <string.h> +#include <sys/types.h> +#include <unistd.h> + +#include <sys/socket.h> + +#include "cloexec.h" + +/* The code that uses CMSG_FIRSTHDR is enabled on + Linux, MacOS X, FreeBSD, OpenBSD, NetBSD, AIX, OSF/1, Cygwin. + The code that uses HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS is enabled on + HP-UX, IRIX, Solaris. */ + +/* MSG_CMSG_CLOEXEC is defined only on Linux, as of 2011. */ +#ifndef MSG_CMSG_CLOEXEC +# define MSG_CMSG_CLOEXEC 0 +#endif + +#if HAVE_SENDMSG +/* sendfd sends the file descriptor fd along the socket + to a process calling recvfd on the other end. + + Return 0 on success, or -1 with errno set in case of error. +*/ +int +sendfd (int sock, int fd) +{ + char byte = 0; + struct iovec iov; + struct msghdr msg; +# ifdef CMSG_FIRSTHDR + struct cmsghdr *cmsg; + char buf[CMSG_SPACE (sizeof fd)]; +# endif + + /* send at least one char */ + memset (&msg, 0, sizeof msg); + iov.iov_base = &byte; + iov.iov_len = 1; + msg.msg_iov = &iov; + msg.msg_iovlen = 1; + msg.msg_name = NULL; + msg.msg_namelen = 0; + +# ifdef CMSG_FIRSTHDR + msg.msg_control = buf; + msg.msg_controllen = sizeof buf; + cmsg = CMSG_FIRSTHDR (&msg); + cmsg->cmsg_level = SOL_SOCKET; + cmsg->cmsg_type = SCM_RIGHTS; + cmsg->cmsg_len = CMSG_LEN (sizeof fd); + /* Initialize the payload: */ + memcpy (CMSG_DATA (cmsg), &fd, sizeof fd); +# elif HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS + msg.msg_accrights = &fd; + msg.msg_accrightslen = sizeof fd; +# else + errno = ENOSYS; + return -1; +# endif + + if (sendmsg (sock, &msg, 0) != iov.iov_len) + return -1; + return 0; +} +#else +int +sendfd (int sock _GL_UNUSED, int fd _GL_UNUSED) +{ + errno = ENOSYS; + return -1; +} +#endif + + +#if HAVE_RECVMSG +/* 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, int flags) +{ + char byte = 0; + struct iovec iov; + struct msghdr msg; + int fd = -1; +# ifdef CMSG_FIRSTHDR + struct cmsghdr *cmsg; + char buf[CMSG_SPACE (sizeof fd)]; + int flags_recvmsg = flags & O_CLOEXEC ? MSG_CMSG_CLOEXEC : 0; +# endif + + if ((flags & ~O_CLOEXEC) != 0) + { + errno = EINVAL; + return -1; + } + + /* send at least one char */ + memset (&msg, 0, sizeof msg); + iov.iov_base = &byte; + iov.iov_len = 1; + msg.msg_iov = &iov; + msg.msg_iovlen = 1; + msg.msg_name = NULL; + msg.msg_namelen = 0; + +# ifdef CMSG_FIRSTHDR + msg.msg_control = buf; + msg.msg_controllen = sizeof buf; + cmsg = CMSG_FIRSTHDR (&msg); + cmsg->cmsg_level = SOL_SOCKET; + cmsg->cmsg_type = SCM_RIGHTS; + cmsg->cmsg_len = CMSG_LEN (sizeof fd); + /* Initialize the payload: */ + memcpy (CMSG_DATA (cmsg), &fd, sizeof fd); + msg.msg_controllen = cmsg->cmsg_len; + + if (recvmsg (sock, &msg, flags_recvmsg) < 0) + return -1; + + cmsg = CMSG_FIRSTHDR (&msg); + /* be paranoiac */ + if (cmsg == NULL || cmsg->cmsg_len != CMSG_LEN (sizeof fd) + || cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS) + { + /* fake errno: at end the file is not available */ + errno = EACCES; + return -1; + } + + memcpy (&fd, CMSG_DATA (cmsg), sizeof fd); + + /* set close-on-exec flag */ + if (!MSG_CMSG_CLOEXEC && (flags & O_CLOEXEC)) + { + if (set_cloexec_flag (fd, true) < 0) + { + int saved_errno = errno; + (void) close (fd); + errno = saved_errno; + return -1; + } + } + +# elif HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS + msg.msg_accrights = &fd; + 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; + close (fd); + errno = saved_errno; + return -1; + } + } +# else + errno = ENOSYS; +# endif + + return fd; +} +#else +int +recvfd (int sock _GL_UNUSED, int flags _GL_UNUSED) +{ + errno = ENOSYS; + return -1; +} +#endif |