/* $OpenBSD: imsg.c,v 1.8 2010/04/07 18:09:39 nicm Exp $ */ /* * Copyright (c) 2003, 2004 Henning Brauer * * 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 #include #include #include #include #include #include #include #include "imsg.h" 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) * 16)]; } cmsgbuf; struct iovec iov; ssize_t n; 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 ((n = recvmsg(ibuf->fd, &msg, 0)) == -1) { if (errno != EINTR && errno != EAGAIN) { return (-1); } return (-2); } 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) { fd = (*(int *)CMSG_DATA(cmsg)); if ((ifd = calloc(1, sizeof(struct imsg_fd))) == NULL) { close(fd); return (-1); } ifd->fd = fd; TAILQ_INSERT_TAIL(&ibuf->fds, ifd, entry); } /* we do not handle other ctl data level */ } 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, void *data, u_int16_t datalen) { struct buf *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 buf *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 buf * imsg_create(struct imsgbuf *ibuf, u_int32_t type, u_int32_t peerid, pid_t pid, u_int16_t datalen) { struct buf *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 = buf_dynamic(datalen, MAX_IMSGSIZE)) == NULL) { return (NULL); } if (imsg_add(wbuf, &hdr, sizeof(hdr)) == -1) return (NULL); return (wbuf); } int imsg_add(struct buf *msg, void *data, u_int16_t datalen) { if (datalen) if (buf_add(msg, data, datalen) == -1) { buf_free(msg); return (-1); } return (datalen); } void imsg_close(struct imsgbuf *ibuf, struct buf *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; buf_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); }