/src/lib/libutil/imsg.c
C | 306 lines | 227 code | 56 blank | 23 comment | 55 complexity | aad2b2f439a2576609715b9cb88e8843 MD5 | raw file
- /* $OpenBSD: imsg.c,v 1.6 2014/06/30 00:26:22 deraadt Exp $ */
- /*
- * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
- *
- * Permission to use, copy, modify, and distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
- * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
- * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- */
- #include <sys/types.h>
- #include <sys/queue.h>
- #include <sys/socket.h>
- #include <sys/uio.h>
- #include <errno.h>
- #include <stdlib.h>
- #include <string.h>
- #include <unistd.h>
- #include "imsg.h"
- int imsg_fd_overhead = 0;
- int imsg_get_fd(struct imsgbuf *);
- void
- imsg_init(struct imsgbuf *ibuf, int fd)
- {
- msgbuf_init(&ibuf->w);
- bzero(&ibuf->r, sizeof(ibuf->r));
- ibuf->fd = fd;
- ibuf->w.fd = fd;
- ibuf->pid = getpid();
- TAILQ_INIT(&ibuf->fds);
- }
- ssize_t
- imsg_read(struct imsgbuf *ibuf)
- {
- struct msghdr msg;
- struct cmsghdr *cmsg;
- union {
- struct cmsghdr hdr;
- char buf[CMSG_SPACE(sizeof(int) * 1)];
- } cmsgbuf;
- struct iovec iov;
- ssize_t n = -1;
- int fd;
- struct imsg_fd *ifd;
- bzero(&msg, sizeof(msg));
- iov.iov_base = ibuf->r.buf + ibuf->r.wpos;
- iov.iov_len = sizeof(ibuf->r.buf) - ibuf->r.wpos;
- msg.msg_iov = &iov;
- msg.msg_iovlen = 1;
- msg.msg_control = &cmsgbuf.buf;
- msg.msg_controllen = sizeof(cmsgbuf.buf);
- if ((ifd = calloc(1, sizeof(struct imsg_fd))) == NULL)
- return (-1);
- #ifndef __FreeBSD__ /* no getdtablecount() */
- again:
- if (getdtablecount() + imsg_fd_overhead +
- (CMSG_SPACE(sizeof(int))-CMSG_SPACE(0))/sizeof(int)
- >= getdtablesize()) {
- errno = EAGAIN;
- free(ifd);
- return (-1);
- }
- #endif
-
- if ((n = recvmsg(ibuf->fd, &msg, 0)) == -1) {
- if (errno == EMSGSIZE)
- goto fail;
- if (errno != EINTR && errno != EAGAIN)
- goto fail;
- #ifndef __FreeBSD__
- goto again;
- #endif
- }
- ibuf->r.wpos += n;
- for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL;
- cmsg = CMSG_NXTHDR(&msg, cmsg)) {
- if (cmsg->cmsg_level == SOL_SOCKET &&
- cmsg->cmsg_type == SCM_RIGHTS) {
- int i;
- int j;
- /*
- * We only accept one file descriptor. Due to C
- * padding rules, our control buffer might contain
- * more than one fd, and we must close them.
- */
- j = ((char *)cmsg + cmsg->cmsg_len -
- (char *)CMSG_DATA(cmsg)) / sizeof(int);
- for (i = 0; i < j; i++) {
- fd = ((int *)CMSG_DATA(cmsg))[i];
- if (ifd != NULL) {
- ifd->fd = fd;
- TAILQ_INSERT_TAIL(&ibuf->fds, ifd,
- entry);
- ifd = NULL;
- } else
- close(fd);
- }
- }
- /* we do not handle other ctl data level */
- }
- fail:
- if (ifd)
- free(ifd);
- return (n);
- }
- ssize_t
- imsg_get(struct imsgbuf *ibuf, struct imsg *imsg)
- {
- size_t av, left, datalen;
- av = ibuf->r.wpos;
- if (IMSG_HEADER_SIZE > av)
- return (0);
- memcpy(&imsg->hdr, ibuf->r.buf, sizeof(imsg->hdr));
- if (imsg->hdr.len < IMSG_HEADER_SIZE ||
- imsg->hdr.len > MAX_IMSGSIZE) {
- errno = ERANGE;
- return (-1);
- }
- if (imsg->hdr.len > av)
- return (0);
- datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
- ibuf->r.rptr = ibuf->r.buf + IMSG_HEADER_SIZE;
- if ((imsg->data = malloc(datalen)) == NULL)
- return (-1);
- if (imsg->hdr.flags & IMSGF_HASFD)
- imsg->fd = imsg_get_fd(ibuf);
- else
- imsg->fd = -1;
- memcpy(imsg->data, ibuf->r.rptr, datalen);
- if (imsg->hdr.len < av) {
- left = av - imsg->hdr.len;
- memmove(&ibuf->r.buf, ibuf->r.buf + imsg->hdr.len, left);
- ibuf->r.wpos = left;
- } else
- ibuf->r.wpos = 0;
- return (datalen + IMSG_HEADER_SIZE);
- }
- int
- imsg_compose(struct imsgbuf *ibuf, u_int32_t type, u_int32_t peerid,
- pid_t pid, int fd, const void *data, u_int16_t datalen)
- {
- struct ibuf *wbuf;
- if ((wbuf = imsg_create(ibuf, type, peerid, pid, datalen)) == NULL)
- return (-1);
- if (imsg_add(wbuf, data, datalen) == -1)
- return (-1);
- wbuf->fd = fd;
- imsg_close(ibuf, wbuf);
- return (1);
- }
- int
- imsg_composev(struct imsgbuf *ibuf, u_int32_t type, u_int32_t peerid,
- pid_t pid, int fd, const struct iovec *iov, int iovcnt)
- {
- struct ibuf *wbuf;
- int i, datalen = 0;
- for (i = 0; i < iovcnt; i++)
- datalen += iov[i].iov_len;
- if ((wbuf = imsg_create(ibuf, type, peerid, pid, datalen)) == NULL)
- return (-1);
- for (i = 0; i < iovcnt; i++)
- if (imsg_add(wbuf, iov[i].iov_base, iov[i].iov_len) == -1)
- return (-1);
- wbuf->fd = fd;
- imsg_close(ibuf, wbuf);
- return (1);
- }
- /* ARGSUSED */
- struct ibuf *
- imsg_create(struct imsgbuf *ibuf, u_int32_t type, u_int32_t peerid,
- pid_t pid, u_int16_t datalen)
- {
- struct ibuf *wbuf;
- struct imsg_hdr hdr;
- datalen += IMSG_HEADER_SIZE;
- if (datalen > MAX_IMSGSIZE) {
- errno = ERANGE;
- return (NULL);
- }
- hdr.type = type;
- hdr.flags = 0;
- hdr.peerid = peerid;
- if ((hdr.pid = pid) == 0)
- hdr.pid = ibuf->pid;
- if ((wbuf = ibuf_dynamic(datalen, MAX_IMSGSIZE)) == NULL) {
- return (NULL);
- }
- if (imsg_add(wbuf, &hdr, sizeof(hdr)) == -1)
- return (NULL);
- return (wbuf);
- }
- int
- imsg_add(struct ibuf *msg, const void *data, u_int16_t datalen)
- {
- if (datalen)
- if (ibuf_add(msg, data, datalen) == -1) {
- ibuf_free(msg);
- return (-1);
- }
- return (datalen);
- }
- void
- imsg_close(struct imsgbuf *ibuf, struct ibuf *msg)
- {
- struct imsg_hdr *hdr;
- hdr = (struct imsg_hdr *)msg->buf;
- hdr->flags &= ~IMSGF_HASFD;
- if (msg->fd != -1)
- hdr->flags |= IMSGF_HASFD;
- hdr->len = (u_int16_t)msg->wpos;
- ibuf_close(&ibuf->w, msg);
- }
- void
- imsg_free(struct imsg *imsg)
- {
- free(imsg->data);
- }
- int
- imsg_get_fd(struct imsgbuf *ibuf)
- {
- int fd;
- struct imsg_fd *ifd;
- if ((ifd = TAILQ_FIRST(&ibuf->fds)) == NULL)
- return (-1);
- fd = ifd->fd;
- TAILQ_REMOVE(&ibuf->fds, ifd, entry);
- free(ifd);
- return (fd);
- }
- int
- imsg_flush(struct imsgbuf *ibuf)
- {
- while (ibuf->w.queued)
- if (msgbuf_write(&ibuf->w) < 0)
- return (-1);
- return (0);
- }
- void
- imsg_clear(struct imsgbuf *ibuf)
- {
- int fd;
- msgbuf_clear(&ibuf->w);
- while ((fd = imsg_get_fd(ibuf)) != -1)
- close(fd);
- }