Index: openbsd-compat/imsg-buffer.c =================================================================== RCS file: openbsd-compat/imsg-buffer.c diff -N openbsd-compat/imsg-buffer.c --- /dev/null 1 Jan 1970 00:00:00 -0000 +++ openbsd-compat/imsg-buffer.c 8 Dec 2012 20:17:59 -0000 1.2 @@ -0,0 +1,305 @@ +/* $OpenBSD: imsg-buffer.c,v 1.1 2010/05/26 16:44:32 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 ibuf_realloc(struct ibuf *, size_t); +void ibuf_enqueue(struct msgbuf *, struct ibuf *); +void ibuf_dequeue(struct msgbuf *, struct ibuf *); + +struct ibuf * +ibuf_open(size_t len) +{ + struct ibuf *buf; + + if ((buf = calloc(1, sizeof(struct ibuf))) == NULL) + return (NULL); + if ((buf->buf = malloc(len)) == NULL) { + free(buf); + return (NULL); + } + buf->size = buf->max = len; + buf->fd = -1; + + return (buf); +} + +struct ibuf * +ibuf_dynamic(size_t len, size_t max) +{ + struct ibuf *buf; + + if (max < len) + return (NULL); + + if ((buf = ibuf_open(len)) == NULL) + return (NULL); + + if (max > 0) + buf->max = max; + + return (buf); +} + +int +ibuf_realloc(struct ibuf *buf, size_t len) +{ + u_char *b; + + /* on static buffers max is eq size and so the following fails */ + if (buf->wpos + len > buf->max) { + errno = ENOMEM; + return (-1); + } + + b = realloc(buf->buf, buf->wpos + len); + if (b == NULL) + return (-1); + buf->buf = b; + buf->size = buf->wpos + len; + + return (0); +} + +int +ibuf_add(struct ibuf *buf, const void *data, size_t len) +{ + if (buf->wpos + len > buf->size) + if (ibuf_realloc(buf, len) == -1) + return (-1); + + memcpy(buf->buf + buf->wpos, data, len); + buf->wpos += len; + return (0); +} + +void * +ibuf_reserve(struct ibuf *buf, size_t len) +{ + void *b; + + if (buf->wpos + len > buf->size) + if (ibuf_realloc(buf, len) == -1) + return (NULL); + + b = buf->buf + buf->wpos; + buf->wpos += len; + return (b); +} + +void * +ibuf_seek(struct ibuf *buf, size_t pos, size_t len) +{ + /* only allowed to seek in already written parts */ + if (pos + len > buf->wpos) + return (NULL); + + return (buf->buf + pos); +} + +size_t +ibuf_size(struct ibuf *buf) +{ + return (buf->wpos); +} + +size_t +ibuf_left(struct ibuf *buf) +{ + return (buf->max - buf->wpos); +} + +void +ibuf_close(struct msgbuf *msgbuf, struct ibuf *buf) +{ + ibuf_enqueue(msgbuf, buf); +} + +int +ibuf_write(struct msgbuf *msgbuf) +{ + struct iovec iov[IOV_MAX]; + struct ibuf *buf; + unsigned int i = 0; + ssize_t n; + + bzero(&iov, sizeof(iov)); + TAILQ_FOREACH(buf, &msgbuf->bufs, entry) { + if (i >= IOV_MAX) + break; + iov[i].iov_base = buf->buf + buf->rpos; + iov[i].iov_len = buf->wpos - buf->rpos; + i++; + } + +again: + if ((n = writev(msgbuf->fd, iov, i)) == -1) { + if (errno == EAGAIN || errno == EINTR) + goto again; + if (errno == ENOBUFS) + errno = EAGAIN; + return (-1); + } + + if (n == 0) { /* connection closed */ + errno = 0; + return (0); + } + + msgbuf_drain(msgbuf, n); + + return (1); +} + +void +ibuf_free(struct ibuf *buf) +{ + free(buf->buf); + free(buf); +} + +void +msgbuf_init(struct msgbuf *msgbuf) +{ + msgbuf->queued = 0; + msgbuf->fd = -1; + TAILQ_INIT(&msgbuf->bufs); +} + +void +msgbuf_drain(struct msgbuf *msgbuf, size_t n) +{ + struct ibuf *buf, *next; + + for (buf = TAILQ_FIRST(&msgbuf->bufs); buf != NULL && n > 0; + buf = next) { + next = TAILQ_NEXT(buf, entry); + if (buf->rpos + n >= buf->wpos) { + n -= buf->wpos - buf->rpos; + ibuf_dequeue(msgbuf, buf); + } else { + buf->rpos += n; + n = 0; + } + } +} + +void +msgbuf_clear(struct msgbuf *msgbuf) +{ + struct ibuf *buf; + + while ((buf = TAILQ_FIRST(&msgbuf->bufs)) != NULL) + ibuf_dequeue(msgbuf, buf); +} + +int +msgbuf_write(struct msgbuf *msgbuf) +{ + struct iovec iov[IOV_MAX]; + struct ibuf *buf; + unsigned int i = 0; + ssize_t n; + struct msghdr msg; + struct cmsghdr *cmsg; + union { + struct cmsghdr hdr; + char buf[CMSG_SPACE(sizeof(int))]; + } cmsgbuf; + + bzero(&iov, sizeof(iov)); + bzero(&msg, sizeof(msg)); + TAILQ_FOREACH(buf, &msgbuf->bufs, entry) { + if (i >= IOV_MAX) + break; + iov[i].iov_base = buf->buf + buf->rpos; + iov[i].iov_len = buf->wpos - buf->rpos; + i++; + if (buf->fd != -1) + break; + } + + msg.msg_iov = iov; + msg.msg_iovlen = i; + + if (buf != NULL && buf->fd != -1) { + msg.msg_control = (caddr_t)&cmsgbuf.buf; + msg.msg_controllen = sizeof(cmsgbuf.buf); + cmsg = CMSG_FIRSTHDR(&msg); + cmsg->cmsg_len = CMSG_LEN(sizeof(int)); + cmsg->cmsg_level = SOL_SOCKET; + cmsg->cmsg_type = SCM_RIGHTS; + *(int *)CMSG_DATA(cmsg) = buf->fd; + } + +again: + if ((n = sendmsg(msgbuf->fd, &msg, 0)) == -1) { + if (errno == EAGAIN || errno == EINTR) + goto again; + if (errno == ENOBUFS) + errno = EAGAIN; + return (-1); + } + + if (n == 0) { /* connection closed */ + errno = 0; + return (0); + } + + /* + * assumption: fd got sent if sendmsg sent anything + * this works because fds are passed one at a time + */ + if (buf != NULL && buf->fd != -1) { + close(buf->fd); + buf->fd = -1; + } + + msgbuf_drain(msgbuf, n); + + return (1); +} + +void +ibuf_enqueue(struct msgbuf *msgbuf, struct ibuf *buf) +{ + TAILQ_INSERT_TAIL(&msgbuf->bufs, buf, entry); + msgbuf->queued++; +} + +void +ibuf_dequeue(struct msgbuf *msgbuf, struct ibuf *buf) +{ + TAILQ_REMOVE(&msgbuf->bufs, buf, entry); + + if (buf->fd != -1) + close(buf->fd); + + msgbuf->queued--; + ibuf_free(buf); +}