diff options
Diffstat (limited to 'compat/imsg.c')
| -rw-r--r-- | compat/imsg.c | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/compat/imsg.c b/compat/imsg.c new file mode 100644 index 0000000..54ac7e5 --- /dev/null +++ b/compat/imsg.c @@ -0,0 +1,302 @@ +/* $OpenBSD: imsg.c,v 1.16 2017/12/14 09:27:44 kettenis 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/socket.h> +#include <sys/uio.h> + +#include <errno.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include "compat.h" +#include "imsg.h" + +int imsg_fd_overhead = 0; + +static int imsg_get_fd(struct imsgbuf *); + +void +imsg_init(struct imsgbuf *ibuf, int fd) +{ + msgbuf_init(&ibuf->w); + memset(&ibuf->r, 0, 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; + + memset(&msg, 0, sizeof(msg)); + memset(&cmsgbuf, 0, sizeof(cmsgbuf)); + + 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); + +again: + if (getdtablecount() + imsg_fd_overhead + + (int)((CMSG_SPACE(sizeof(int))-CMSG_SPACE(0))/sizeof(int)) + >= getdtablesize()) { + errno = EAGAIN; + free(ifd); + return (-1); + } + + if ((n = recvmsg(ibuf->fd, &msg, 0)) == -1) { + if (errno == EINTR) + goto again; + goto fail; + } + + 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: + 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 (datalen == 0) + imsg->data = NULL; + else 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, uint32_t type, uint32_t peerid, pid_t pid, + int fd, const void *data, uint16_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, uint32_t type, uint32_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, uint32_t type, uint32_t peerid, pid_t pid, + uint16_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, uint16_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 = (uint16_t)msg->wpos; + + ibuf_close(&ibuf->w, msg); +} + +void +imsg_free(struct imsg *imsg) +{ + freezero(imsg->data, imsg->hdr.len - IMSG_HEADER_SIZE); +} + +static 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); +} |