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/* $OpenBSD: imsg.c,v 1.15 2017/04/11 09:57:19 reyk Exp $ */ |
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/* |
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* Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org> |
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* |
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* Permission to use, copy, modify, and distribute this software for any |
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* purpose with or without fee is hereby granted, provided that the above |
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* copyright notice and this permission notice appear in all copies. |
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* |
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
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*/ |
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#include <sys/types.h> |
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#include <sys/queue.h> |
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#include <sys/socket.h> |
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#include <sys/uio.h> |
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#include <errno.h> |
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#include <stdlib.h> |
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#include <string.h> |
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#include <unistd.h> |
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#include "imsg.h" |
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int imsg_fd_overhead = 0; |
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int imsg_get_fd(struct imsgbuf *); |
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void |
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imsg_init(struct imsgbuf *ibuf, int fd) |
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{ |
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msgbuf_init(&ibuf->w); |
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memset(&ibuf->r, 0, sizeof(ibuf->r)); |
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ibuf->fd = fd; |
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ibuf->w.fd = fd; |
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ibuf->pid = getpid(); |
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TAILQ_INIT(&ibuf->fds); |
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} |
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ssize_t |
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imsg_read(struct imsgbuf *ibuf) |
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{ |
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struct msghdr msg; |
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struct cmsghdr *cmsg; |
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union { |
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struct cmsghdr hdr; |
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char buf[CMSG_SPACE(sizeof(int) * 1)]; |
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} cmsgbuf; |
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struct iovec iov; |
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ssize_t n = -1; |
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int fd; |
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struct imsg_fd *ifd; |
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memset(&msg, 0, sizeof(msg)); |
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memset(&cmsgbuf, 0, sizeof(cmsgbuf)); |
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iov.iov_base = ibuf->r.buf + ibuf->r.wpos; |
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iov.iov_len = sizeof(ibuf->r.buf) - ibuf->r.wpos; |
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msg.msg_iov = &iov; |
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msg.msg_iovlen = 1; |
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msg.msg_control = &cmsgbuf.buf; |
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msg.msg_controllen = sizeof(cmsgbuf.buf); |
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if ((ifd = calloc(1, sizeof(struct imsg_fd))) == NULL) |
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return (-1); |
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again: |
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if (getdtablecount() + imsg_fd_overhead + |
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(int)((CMSG_SPACE(sizeof(int))-CMSG_SPACE(0))/sizeof(int)) |
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>= getdtablesize()) { |
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errno = EAGAIN; |
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free(ifd); |
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return (-1); |
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} |
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if ((n = recvmsg(ibuf->fd, &msg, 0)) == -1) { |
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if (errno == EINTR) |
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goto again; |
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goto fail; |
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} |
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ibuf->r.wpos += n; |
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for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; |
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cmsg = CMSG_NXTHDR(&msg, cmsg)) { |
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if (cmsg->cmsg_level == SOL_SOCKET && |
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cmsg->cmsg_type == SCM_RIGHTS) { |
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int i; |
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int j; |
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/* |
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* We only accept one file descriptor. Due to C |
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* padding rules, our control buffer might contain |
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* more than one fd, and we must close them. |
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*/ |
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j = ((char *)cmsg + cmsg->cmsg_len - |
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(char *)CMSG_DATA(cmsg)) / sizeof(int); |
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for (i = 0; i < j; i++) { |
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fd = ((int *)CMSG_DATA(cmsg))[i]; |
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if (ifd != NULL) { |
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ifd->fd = fd; |
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TAILQ_INSERT_TAIL(&ibuf->fds, ifd, |
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entry); |
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ifd = NULL; |
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} else |
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close(fd); |
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} |
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} |
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/* we do not handle other ctl data level */ |
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} |
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fail: |
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free(ifd); |
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return (n); |
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} |
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ssize_t |
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imsg_get(struct imsgbuf *ibuf, struct imsg *imsg) |
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{ |
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size_t av, left, datalen; |
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av = ibuf->r.wpos; |
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if (IMSG_HEADER_SIZE > av) |
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return (0); |
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memcpy(&imsg->hdr, ibuf->r.buf, sizeof(imsg->hdr)); |
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if (imsg->hdr.len < IMSG_HEADER_SIZE || |
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imsg->hdr.len > MAX_IMSGSIZE) { |
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errno = ERANGE; |
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return (-1); |
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} |
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if (imsg->hdr.len > av) |
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return (0); |
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datalen = imsg->hdr.len - IMSG_HEADER_SIZE; |
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ibuf->r.rptr = ibuf->r.buf + IMSG_HEADER_SIZE; |
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if (datalen == 0) |
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imsg->data = NULL; |
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else if ((imsg->data = malloc(datalen)) == NULL) |
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return (-1); |
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if (imsg->hdr.flags & IMSGF_HASFD) |
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imsg->fd = imsg_get_fd(ibuf); |
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else |
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imsg->fd = -1; |
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memcpy(imsg->data, ibuf->r.rptr, datalen); |
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if (imsg->hdr.len < av) { |
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left = av - imsg->hdr.len; |
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memmove(&ibuf->r.buf, ibuf->r.buf + imsg->hdr.len, left); |
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ibuf->r.wpos = left; |
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} else |
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ibuf->r.wpos = 0; |
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return (datalen + IMSG_HEADER_SIZE); |
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} |
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int |
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imsg_compose(struct imsgbuf *ibuf, uint32_t type, uint32_t peerid, pid_t pid, |
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int fd, const void *data, uint16_t datalen) |
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{ |
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struct ibuf *wbuf; |
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if ((wbuf = imsg_create(ibuf, type, peerid, pid, datalen)) == NULL) |
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return (-1); |
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if (imsg_add(wbuf, data, datalen) == -1) |
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return (-1); |
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wbuf->fd = fd; |
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imsg_close(ibuf, wbuf); |
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return (1); |
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} |
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int |
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imsg_composev(struct imsgbuf *ibuf, uint32_t type, uint32_t peerid, pid_t pid, |
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int fd, const struct iovec *iov, int iovcnt) |
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{ |
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struct ibuf *wbuf; |
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int i, datalen = 0; |
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for (i = 0; i < iovcnt; i++) |
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datalen += iov[i].iov_len; |
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if ((wbuf = imsg_create(ibuf, type, peerid, pid, datalen)) == NULL) |
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return (-1); |
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for (i = 0; i < iovcnt; i++) |
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if (imsg_add(wbuf, iov[i].iov_base, iov[i].iov_len) == -1) |
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return (-1); |
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wbuf->fd = fd; |
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imsg_close(ibuf, wbuf); |
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return (1); |
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} |
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/* ARGSUSED */ |
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struct ibuf * |
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imsg_create(struct imsgbuf *ibuf, uint32_t type, uint32_t peerid, pid_t pid, |
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uint16_t datalen) |
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{ |
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struct ibuf *wbuf; |
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struct imsg_hdr hdr; |
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datalen += IMSG_HEADER_SIZE; |
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if (datalen > MAX_IMSGSIZE) { |
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errno = ERANGE; |
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return (NULL); |
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} |
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hdr.type = type; |
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hdr.flags = 0; |
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hdr.peerid = peerid; |
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if ((hdr.pid = pid) == 0) |
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hdr.pid = ibuf->pid; |
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if ((wbuf = ibuf_dynamic(datalen, MAX_IMSGSIZE)) == NULL) { |
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return (NULL); |
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} |
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if (imsg_add(wbuf, &hdr, sizeof(hdr)) == -1) |
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return (NULL); |
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return (wbuf); |
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} |
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int |
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imsg_add(struct ibuf *msg, const void *data, uint16_t datalen) |
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{ |
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if (datalen) |
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if (ibuf_add(msg, data, datalen) == -1) { |
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ibuf_free(msg); |
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return (-1); |
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} |
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return (datalen); |
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} |
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void |
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imsg_close(struct imsgbuf *ibuf, struct ibuf *msg) |
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{ |
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struct imsg_hdr *hdr; |
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hdr = (struct imsg_hdr *)msg->buf; |
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hdr->flags &= ~IMSGF_HASFD; |
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if (msg->fd != -1) |
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hdr->flags |= IMSGF_HASFD; |
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hdr->len = (uint16_t)msg->wpos; |
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ibuf_close(&ibuf->w, msg); |
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} |
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void |
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imsg_free(struct imsg *imsg) |
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{ |
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freezero(imsg->data, imsg->hdr.len - IMSG_HEADER_SIZE); |
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} |
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int |
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imsg_get_fd(struct imsgbuf *ibuf) |
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{ |
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int fd; |
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struct imsg_fd *ifd; |
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if ((ifd = TAILQ_FIRST(&ibuf->fds)) == NULL) |
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return (-1); |
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fd = ifd->fd; |
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TAILQ_REMOVE(&ibuf->fds, ifd, entry); |
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free(ifd); |
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return (fd); |
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} |
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int |
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imsg_flush(struct imsgbuf *ibuf) |
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{ |
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while (ibuf->w.queued) |
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if (msgbuf_write(&ibuf->w) <= 0) |
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return (-1); |
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return (0); |
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} |
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void |
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imsg_clear(struct imsgbuf *ibuf) |
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{ |
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int fd; |
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msgbuf_clear(&ibuf->w); |
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while ((fd = imsg_get_fd(ibuf)) != -1) |
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close(fd); |
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} |