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74b3dd4630
Found and confirmed to work by albert chin (china@thewrittenword.com) Signed-off-by: Volker Lendecke <vl@samba.org> Reviewed-by: Jeremy Allison <jra@samba.org>
274 lines
5.6 KiB
C
274 lines
5.6 KiB
C
/*
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* Unix SMB/CIFS implementation.
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* Copyright (C) Volker Lendecke 2014
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "replace.h"
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#include "lib/util/msghdr.h"
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#include "lib/util/iov_buf.h"
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#include <sys/socket.h>
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#if defined(HAVE_STRUCT_MSGHDR_MSG_CONTROL)
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ssize_t msghdr_prep_fds(struct msghdr *msg, uint8_t *buf, size_t bufsize,
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const int *fds, size_t num_fds)
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{
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size_t fds_size = sizeof(int) * MIN(num_fds, INT8_MAX);
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size_t cmsg_len = CMSG_LEN(fds_size);
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size_t cmsg_space = CMSG_SPACE(fds_size);
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struct cmsghdr *cmsg;
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void *fdptr;
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if (num_fds == 0) {
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if (msg != NULL) {
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msg->msg_control = NULL;
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msg->msg_controllen = 0;
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}
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/*
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* C99 doesn't allow 0-length arrays
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*/
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return 1;
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}
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if (num_fds > INT8_MAX) {
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return -1;
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}
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if ((msg == NULL) || (cmsg_space > bufsize)) {
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/*
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* C99 doesn't allow 0-length arrays
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*/
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return MAX(cmsg_space, 1);
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}
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msg->msg_control = buf;
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msg->msg_controllen = cmsg_space;
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cmsg = CMSG_FIRSTHDR(msg);
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cmsg->cmsg_level = SOL_SOCKET;
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cmsg->cmsg_type = SCM_RIGHTS;
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cmsg->cmsg_len = cmsg_len;
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fdptr = CMSG_DATA(cmsg);
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memcpy(fdptr, fds, fds_size);
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msg->msg_controllen = cmsg->cmsg_len;
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return cmsg_space;
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}
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size_t msghdr_prep_recv_fds(struct msghdr *msg, uint8_t *buf, size_t bufsize,
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size_t num_fds)
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{
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size_t ret = CMSG_SPACE(sizeof(int) * num_fds);
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if (bufsize < ret) {
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return ret;
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}
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if (msg != NULL) {
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if (num_fds != 0) {
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msg->msg_control = buf;
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msg->msg_controllen = ret;
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} else {
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msg->msg_control = NULL;
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msg->msg_controllen = 0;
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}
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}
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return ret;
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}
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size_t msghdr_extract_fds(struct msghdr *msg, int *fds, size_t fds_size)
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{
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struct cmsghdr *cmsg;
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size_t num_fds;
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for(cmsg = CMSG_FIRSTHDR(msg);
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cmsg != NULL;
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cmsg = CMSG_NXTHDR(msg, cmsg))
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{
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if ((cmsg->cmsg_type == SCM_RIGHTS) &&
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(cmsg->cmsg_level == SOL_SOCKET)) {
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break;
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}
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}
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if (cmsg == NULL) {
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return 0;
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}
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num_fds = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int);
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if ((num_fds != 0) && (fds != NULL) && (fds_size >= num_fds)) {
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memcpy(fds, CMSG_DATA(cmsg), num_fds * sizeof(int));
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}
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return num_fds;
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}
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#elif defined(HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS)
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ssize_t msghdr_prep_fds(struct msghdr *msg, uint8_t *buf, size_t bufsize,
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const int *fds, size_t num_fds)
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{
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size_t needed;
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if (num_fds > INT8_MAX) {
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return -1;
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}
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needed = sizeof(int) * num_fds;
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if ((msg == NULL) || (needed > bufsize)) {
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return needed;
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}
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memcpy(buf, fds, needed);
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msg->msg_accrights = (caddr_t) buf;
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msg->msg_accrightslen = needed;
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return needed;
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}
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size_t msghdr_prep_recv_fds(struct msghdr *msg, uint8_t *buf, size_t bufsize,
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size_t num_fds)
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{
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size_t ret = num_fds * sizeof(int);
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if (bufsize < ret) {
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return ret;
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}
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if (msg != NULL) {
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if (num_fds != 0) {
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msg->msg_accrights = (caddr_t) buf;
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msg->msg_accrightslen = ret;
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} else {
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msg->msg_accrights = NULL;
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msg->msg_accrightslen = 0;
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}
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}
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return ret;
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}
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size_t msghdr_extract_fds(struct msghdr *msg, int *fds, size_t fds_size)
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{
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size_t num_fds = msg->msg_accrightslen / sizeof(int);
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if ((fds != 0) && (num_fds <= fds_size)) {
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memcpy(fds, msg->msg_accrights, msg->msg_accrightslen);
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}
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return num_fds;
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}
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#else
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ssize_t msghdr_prep_fds(struct msghdr *msg, uint8_t *buf, size_t bufsize,
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const int *fds, size_t num_fds)
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{
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return -1;
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}
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size_t msghdr_prep_recv_fds(struct msghdr *msg, uint8_t *buf, size_t bufsize,
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size_t num_fds)
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{
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return 0;
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}
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size_t msghdr_extract_fds(struct msghdr *msg, int *fds, size_t fds_size)
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{
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return 0;
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}
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#endif
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struct msghdr_buf {
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struct msghdr msg;
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struct sockaddr_storage addr;
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struct iovec iov;
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uint8_t buf[];
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};
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ssize_t msghdr_copy(struct msghdr_buf *msg, size_t msgsize,
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const void *addr, socklen_t addrlen,
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const struct iovec *iov, int iovcnt,
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const int *fds, size_t num_fds)
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{
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ssize_t fd_len;
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size_t iov_len, needed, bufsize;
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bufsize = (msgsize > offsetof(struct msghdr_buf, buf)) ?
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msgsize - offsetof(struct msghdr_buf, buf) : 0;
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if (msg != NULL) {
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msg->msg = (struct msghdr) { 0 };
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fd_len = msghdr_prep_fds(&msg->msg, msg->buf, bufsize,
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fds, num_fds);
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} else {
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fd_len = msghdr_prep_fds(NULL, NULL, bufsize, fds, num_fds);
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}
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if (fd_len == -1) {
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return -1;
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}
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if (bufsize >= fd_len) {
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bufsize -= fd_len;
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} else {
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bufsize = 0;
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}
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if (msg != NULL) {
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if (addr != NULL) {
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if (addrlen > sizeof(struct sockaddr_storage)) {
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errno = EMSGSIZE;
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return -1;
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}
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memcpy(&msg->addr, addr, addrlen);
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msg->msg.msg_name = &msg->addr;
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msg->msg.msg_namelen = addrlen;
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} else {
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msg->msg.msg_name = NULL;
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msg->msg.msg_namelen = 0;
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}
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msg->iov.iov_base = msg->buf + fd_len;
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msg->iov.iov_len = iov_buf(
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iov, iovcnt, msg->iov.iov_base, bufsize);
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iov_len = msg->iov.iov_len;
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msg->msg.msg_iov = &msg->iov;
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msg->msg.msg_iovlen = 1;
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} else {
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iov_len = iov_buflen(iov, iovcnt);
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}
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needed = offsetof(struct msghdr_buf, buf) + fd_len;
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if (needed < fd_len) {
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return -1;
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}
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needed += iov_len;
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if (needed < iov_len) {
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return -1;
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}
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return needed;
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}
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struct msghdr *msghdr_buf_msghdr(struct msghdr_buf *msg)
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{
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return &msg->msg;
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}
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