]> git.proxmox.com Git - mirror_frr.git/blobdiff - lib/imsg-buffer.c
ldpd: copy original sources from OpenBSD (14/09/2016)
[mirror_frr.git] / lib / imsg-buffer.c
diff --git a/lib/imsg-buffer.c b/lib/imsg-buffer.c
new file mode 100644 (file)
index 0000000..61b2c09
--- /dev/null
@@ -0,0 +1,309 @@
+/*     $OpenBSD$       */
+
+/*
+ * 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 <limits.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#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 = ERANGE;
+               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;
+
+       memset(&iov, 0, 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 == 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)
+{
+       if (buf == NULL)
+               return;
+       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;
+
+       memset(&iov, 0, sizeof(iov));
+       memset(&msg, 0, sizeof(msg));
+       memset(&cmsgbuf, 0, sizeof(cmsgbuf));
+       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 == 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);
+}