commit c8b8dc5c502e3b69cc28f29c0a9570a8378488c6
from: Omar Polo <op@omarpolo.com>
date: Fri Mar 28 16:58:08 2025 UTC

update imsg

commit - cfe4e15a08dd6e6a8bec9b9fdaa12358e52ee149
commit + c8b8dc5c502e3b69cc28f29c0a9570a8378488c6
blob - 51f90f8b2cf295a14f4590dbc498e143fd0e5a35
blob + 41e4f38a4f1d53afb30ce03de93feefd7d4934fb
--- compat/imsg-buffer.c
+++ compat/imsg-buffer.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: imsg-buffer.c,v 1.18 2023/12/12 15:47:41 claudio Exp $	*/
+/*	$OpenBSD: imsg-buffer.c,v 1.31 2024/11/26 13:57:31 claudio Exp $	*/
 
 /*
  * Copyright (c) 2023 Claudio Jeker <claudio@openbsd.org>
@@ -32,25 +32,37 @@
 
 #include "imsg.h"
 
-static int	ibuf_realloc(struct ibuf *, size_t);
-static void	ibuf_enqueue(struct msgbuf *, struct ibuf *);
-static void	ibuf_dequeue(struct msgbuf *, struct ibuf *);
+struct msgbuf {
+	TAILQ_HEAD(, ibuf)	 bufs;
+	TAILQ_HEAD(, ibuf)	 rbufs;
+	uint32_t		 queued;
+	char			*rbuf;
+	struct ibuf		*rpmsg;
+	struct ibuf		*(*readhdr)(struct ibuf *, void *, int *);
+	void			*rarg;
+	size_t			 roff;
+	size_t			 hdrsize;
+};
+
+static void	msgbuf_read_enqueue(struct msgbuf *, struct ibuf *);
+static void	msgbuf_enqueue(struct msgbuf *, struct ibuf *);
+static void	msgbuf_dequeue(struct msgbuf *, struct ibuf *);
 static void	msgbuf_drain(struct msgbuf *, size_t);
 
+#define	IBUF_FD_MARK_ON_STACK	-2
+
 struct ibuf *
 ibuf_open(size_t len)
 {
 	struct ibuf	*buf;
 
-	if (len == 0) {
-		errno = EINVAL;
-		return (NULL);
-	}
 	if ((buf = calloc(1, sizeof(struct ibuf))) == NULL)
 		return (NULL);
-	if ((buf->buf = calloc(len, 1)) == NULL) {
-		free(buf);
-		return (NULL);
+	if (len > 0) {
+		if ((buf->buf = calloc(len, 1)) == NULL) {
+			free(buf);
+			return (NULL);
+		}
 	}
 	buf->size = buf->max = len;
 	buf->fd = -1;
@@ -83,39 +95,36 @@ ibuf_dynamic(size_t len, size_t max)
 	return (buf);
 }
 
-static int
-ibuf_realloc(struct ibuf *buf, size_t len)
-{
-	unsigned char	*b;
-
-	/* on static buffers max is eq size and so the following fails */
-	if (len > SIZE_MAX - buf->wpos || buf->wpos + len > buf->max) {
-		errno = ERANGE;
-		return (-1);
-	}
-
-	b = recallocarray(buf->buf, buf->size, buf->wpos + len, 1);
-	if (b == NULL)
-		return (-1);
-	buf->buf = b;
-	buf->size = buf->wpos + len;
-
-	return (0);
-}
-
 void *
 ibuf_reserve(struct ibuf *buf, size_t len)
 {
 	void	*b;
 
-	if (len > SIZE_MAX - buf->wpos || buf->max == 0) {
+	if (len > SIZE_MAX - buf->wpos) {
 		errno = ERANGE;
 		return (NULL);
 	}
+	if (buf->fd == IBUF_FD_MARK_ON_STACK) {
+		/* can not grow stack buffers */
+		errno = EINVAL;
+		return (NULL);
+	}
 
-	if (buf->wpos + len > buf->size)
-		if (ibuf_realloc(buf, len) == -1)
+	if (buf->wpos + len > buf->size) {
+		unsigned char	*nb;
+
+		/* check if buffer is allowed to grow */
+		if (buf->wpos + len > buf->max) {
+			errno = ERANGE;
 			return (NULL);
+		}
+		nb = realloc(buf->buf, buf->wpos + len);
+		if (nb == NULL)
+			return (NULL);
+		memset(nb + buf->size, 0, buf->wpos + len - buf->size);
+		buf->buf = nb;
+		buf->size = buf->wpos + len;
+	}
 
 	b = buf->buf + buf->wpos;
 	buf->wpos += len;
@@ -140,14 +149,7 @@ ibuf_add_ibuf(struct ibuf *buf, const struct ibuf *fro
 	return ibuf_add(buf, ibuf_data(from), ibuf_size(from));
 }
 
-/* remove after tree is converted */
 int
-ibuf_add_buf(struct ibuf *buf, const struct ibuf *from)
-{
-	return ibuf_add_ibuf(buf, from);
-}
-
-int
 ibuf_add_n8(struct ibuf *buf, uint64_t value)
 {
 	uint8_t v;
@@ -354,7 +356,8 @@ ibuf_size(const struct ibuf *buf)
 size_t
 ibuf_left(const struct ibuf *buf)
 {
-	if (buf->max == 0)
+	/* on stack buffers have no space left */
+	if (buf->fd == IBUF_FD_MARK_ON_STACK)
 		return (0);
 	return (buf->max - buf->wpos);
 }
@@ -366,8 +369,8 @@ ibuf_truncate(struct ibuf *buf, size_t len)
 		buf->wpos = buf->rpos + len;
 		return (0);
 	}
-	if (buf->max == 0) {
-		/* only allow to truncate down */
+	if (buf->fd == IBUF_FD_MARK_ON_STACK) {
+		/* only allow to truncate down for stack buffers */
 		errno = ERANGE;
 		return (-1);
 	}
@@ -383,7 +386,7 @@ ibuf_rewind(struct ibuf *buf)
 void
 ibuf_close(struct msgbuf *msgbuf, struct ibuf *buf)
 {
-	ibuf_enqueue(msgbuf, buf);
+	msgbuf_enqueue(msgbuf, buf);
 }
 
 void
@@ -392,7 +395,7 @@ ibuf_from_buffer(struct ibuf *buf, void *data, size_t 
 	memset(buf, 0, sizeof(*buf));
 	buf->buf = data;
 	buf->size = buf->wpos = len;
-	buf->fd = -1;
+	buf->fd = IBUF_FD_MARK_ON_STACK;
 }
 
 void
@@ -425,9 +428,27 @@ ibuf_get_ibuf(struct ibuf *buf, size_t len, struct ibu
 	ibuf_from_buffer(new, ibuf_data(buf), len);
 	buf->rpos += len;
 	return (0);
+}
+
+int
+ibuf_get_h16(struct ibuf *buf, uint16_t *value)
+{
+	return ibuf_get(buf, value, sizeof(*value));
 }
 
 int
+ibuf_get_h32(struct ibuf *buf, uint32_t *value)
+{
+	return ibuf_get(buf, value, sizeof(*value));
+}
+
+int
+ibuf_get_h64(struct ibuf *buf, uint64_t *value)
+{
+	return ibuf_get(buf, value, sizeof(*value));
+}
+
+int
 ibuf_get_n8(struct ibuf *buf, uint8_t *value)
 {
 	return ibuf_get(buf, value, sizeof(*value));
@@ -463,22 +484,21 @@ ibuf_get_n64(struct ibuf *buf, uint64_t *value)
 	return (rv);
 }
 
-int
-ibuf_get_h16(struct ibuf *buf, uint16_t *value)
+char *
+ibuf_get_string(struct ibuf *buf, size_t len)
 {
-	return ibuf_get(buf, value, sizeof(*value));
-}
+	char *str;
 
-int
-ibuf_get_h32(struct ibuf *buf, uint32_t *value)
-{
-	return ibuf_get(buf, value, sizeof(*value));
-}
+	if (ibuf_size(buf) < len) {
+		errno = EBADMSG;
+		return (NULL);
+	}
 
-int
-ibuf_get_h64(struct ibuf *buf, uint64_t *value)
-{
-	return ibuf_get(buf, value, sizeof(*value));
+	str = strndup(ibuf_data(buf), len);
+	if (str == NULL)
+		return (NULL);
+	buf->rpos += len;
+	return (str);
 }
 
 int
@@ -498,9 +518,10 @@ ibuf_free(struct ibuf *buf)
 {
 	if (buf == NULL)
 		return;
-	if (buf->max == 0)	/* if buf lives on the stack */
-		abort();	/* abort before causing more harm */
-	if (buf->fd != -1)
+	/* if buf lives on the stack abort before causing more harm */
+	if (buf->fd == IBUF_FD_MARK_ON_STACK)
+		abort();
+	if (buf->fd >= 0)
 		close(buf->fd);
 	freezero(buf->buf, buf->size);
 	free(buf);
@@ -509,7 +530,7 @@ ibuf_free(struct ibuf *buf)
 int
 ibuf_fd_avail(struct ibuf *buf)
 {
-	return (buf->fd != -1);
+	return (buf->fd >= 0);
 }
 
 int
@@ -517,6 +538,9 @@ ibuf_fd_get(struct ibuf *buf)
 {
 	int fd;
 
+	/* negative fds are internal use and equivalent to -1 */
+	if (buf->fd < 0)
+		return (-1);
 	fd = buf->fd;
 	buf->fd = -1;
 	return (fd);
@@ -525,73 +549,73 @@ ibuf_fd_get(struct ibuf *buf)
 void
 ibuf_fd_set(struct ibuf *buf, int fd)
 {
-	if (buf->max == 0)	/* if buf lives on the stack */
-		abort();	/* abort before causing more harm */
-	if (buf->fd != -1)
+	/* if buf lives on the stack abort before causing more harm */
+	if (buf->fd == IBUF_FD_MARK_ON_STACK)
+		abort();
+	if (buf->fd >= 0)
 		close(buf->fd);
-	buf->fd = fd;
+	buf->fd = -1;
+	if (fd >= 0)
+		buf->fd = fd;
 }
 
-int
-ibuf_write(struct msgbuf *msgbuf)
+struct msgbuf *
+msgbuf_new(void)
 {
-	struct iovec	 iov[IOV_MAX];
-	struct ibuf	*buf;
-	unsigned int	 i = 0;
-	ssize_t	n;
+	struct msgbuf *msgbuf;
 
-	memset(&iov, 0, sizeof(iov));
-	TAILQ_FOREACH(buf, &msgbuf->bufs, entry) {
-		if (i >= IOV_MAX)
-			break;
-		iov[i].iov_base = ibuf_data(buf);
-		iov[i].iov_len = ibuf_size(buf);
-		i++;
-	}
+	if ((msgbuf = calloc(1, sizeof(*msgbuf))) == NULL)
+		return (NULL);
+	msgbuf->queued = 0;
+	TAILQ_INIT(&msgbuf->bufs);
+	TAILQ_INIT(&msgbuf->rbufs);
 
-again:
-	if ((n = writev(msgbuf->fd, iov, i)) == -1) {
-		if (errno == EINTR)
-			goto again;
-		if (errno == ENOBUFS)
-			errno = EAGAIN;
-		return (-1);
+	return msgbuf;
+}
+
+struct msgbuf *
+msgbuf_new_reader(size_t hdrsz,
+    struct ibuf *(*readhdr)(struct ibuf *, void *, int *), void *arg)
+{
+	struct msgbuf *msgbuf;
+	char *buf;
+
+	if (hdrsz == 0 || hdrsz > IBUF_READ_SIZE / 2) {
+		errno = EINVAL;
+		return (NULL);
 	}
 
-	if (n == 0) {			/* connection closed */
-		errno = 0;
-		return (0);
+	if ((buf = malloc(IBUF_READ_SIZE)) == NULL)
+		return (NULL);
+
+	msgbuf = msgbuf_new();
+	if (msgbuf == NULL) {
+		free(buf);
+		return (NULL);
 	}
 
-	msgbuf_drain(msgbuf, n);
+	msgbuf->rbuf = buf;
+	msgbuf->hdrsize = hdrsz;
+	msgbuf->readhdr = readhdr;
+	msgbuf->rarg = arg;
 
-	return (1);
+	return (msgbuf);
 }
 
 void
-msgbuf_init(struct msgbuf *msgbuf)
+msgbuf_free(struct msgbuf *msgbuf)
 {
-	msgbuf->queued = 0;
-	msgbuf->fd = -1;
-	TAILQ_INIT(&msgbuf->bufs);
+	if (msgbuf == NULL)
+		return;
+	msgbuf_clear(msgbuf);
+	free(msgbuf->rbuf);
+	free(msgbuf);
 }
 
-static void
-msgbuf_drain(struct msgbuf *msgbuf, size_t n)
+uint32_t
+msgbuf_queuelen(struct msgbuf *msgbuf)
 {
-	struct ibuf	*buf, *next;
-
-	for (buf = TAILQ_FIRST(&msgbuf->bufs); buf != NULL && n > 0;
-	    buf = next) {
-		next = TAILQ_NEXT(buf, entry);
-		if (n >= ibuf_size(buf)) {
-			n -= ibuf_size(buf);
-			ibuf_dequeue(msgbuf, buf);
-		} else {
-			buf->rpos += n;
-			n = 0;
-		}
-	}
+	return (msgbuf->queued);
 }
 
 void
@@ -599,14 +623,68 @@ msgbuf_clear(struct msgbuf *msgbuf)
 {
 	struct ibuf	*buf;
 
+	/* write side */
 	while ((buf = TAILQ_FIRST(&msgbuf->bufs)) != NULL)
-		ibuf_dequeue(msgbuf, buf);
+		msgbuf_dequeue(msgbuf, buf);
+	msgbuf->queued = 0;
+
+	/* read side */
+	while ((buf = TAILQ_FIRST(&msgbuf->rbufs)) != NULL) {
+		TAILQ_REMOVE(&msgbuf->rbufs, buf, entry);
+		ibuf_free(buf);
+	}
+	msgbuf->roff = 0;
+	ibuf_free(msgbuf->rpmsg);
+	msgbuf->rpmsg = NULL;
+}
+
+struct ibuf *
+msgbuf_get(struct msgbuf *msgbuf)
+{
+	struct ibuf	*buf;
+
+	if ((buf = TAILQ_FIRST(&msgbuf->rbufs)) != NULL)
+		TAILQ_REMOVE(&msgbuf->rbufs, buf, entry);
+	return buf;
 }
 
 int
-msgbuf_write(struct msgbuf *msgbuf)
+ibuf_write(int fd, 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 = ibuf_data(buf);
+		iov[i].iov_len = ibuf_size(buf);
+		i++;
+	}
+	if (i == 0)
+		return (0);	/* nothing queued */
+
+ again:
+	if ((n = writev(fd, iov, i)) == -1) {
+		if (errno == EINTR)
+			goto again;
+		if (errno == EAGAIN || errno == ENOBUFS)
+			/* lets retry later again */
+			return (0);
+		return (-1);
+	}
+
+	msgbuf_drain(msgbuf, n);
+	return (0);
+}
+
+int
+msgbuf_write(int fd, struct msgbuf *msgbuf)
+{
+	struct iovec	 iov[IOV_MAX];
 	struct ibuf	*buf, *buf0 = NULL;
 	unsigned int	 i = 0;
 	ssize_t		 n;
@@ -632,6 +710,9 @@ msgbuf_write(struct msgbuf *msgbuf)
 			buf0 = buf;
 	}
 
+	if (i == 0)
+		return (0);	/* nothing queued */
+
 	msg.msg_iov = iov;
 	msg.msg_iovlen = i;
 
@@ -645,20 +726,16 @@ msgbuf_write(struct msgbuf *msgbuf)
 		*(int *)CMSG_DATA(cmsg) = buf0->fd;
 	}
 
-again:
-	if ((n = sendmsg(msgbuf->fd, &msg, 0)) == -1) {
+ again:
+	if ((n = sendmsg(fd, &msg, 0)) == -1) {
 		if (errno == EINTR)
 			goto again;
-		if (errno == ENOBUFS)
-			errno = EAGAIN;
+		if (errno == EAGAIN || errno == ENOBUFS)
+			/* lets retry later again */
+			return (0);
 		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
@@ -670,28 +747,209 @@ again:
 
 	msgbuf_drain(msgbuf, n);
 
+	return (0);
+}
+
+static int
+ibuf_read_process(struct msgbuf *msgbuf, int fd)
+{
+	struct ibuf rbuf, msg;
+	ssize_t sz;
+
+	ibuf_from_buffer(&rbuf, msgbuf->rbuf, msgbuf->roff);
+
+	do {
+		if (msgbuf->rpmsg == NULL) {
+			if (ibuf_size(&rbuf) < msgbuf->hdrsize)
+				break;
+			/* get size from header */
+			ibuf_from_buffer(&msg, ibuf_data(&rbuf),
+			    msgbuf->hdrsize);
+			if ((msgbuf->rpmsg = msgbuf->readhdr(&msg,
+			    msgbuf->rarg, &fd)) == NULL)
+				goto fail;
+		}
+
+		if (ibuf_left(msgbuf->rpmsg) <= ibuf_size(&rbuf))
+			sz = ibuf_left(msgbuf->rpmsg);
+		else
+			sz = ibuf_size(&rbuf);
+
+		/* neither call below can fail */
+		if (ibuf_get_ibuf(&rbuf, sz, &msg) == -1 ||
+		    ibuf_add_ibuf(msgbuf->rpmsg, &msg) == -1)
+			goto fail;
+
+		if (ibuf_left(msgbuf->rpmsg) == 0) {
+			msgbuf_read_enqueue(msgbuf, msgbuf->rpmsg);
+			msgbuf->rpmsg = NULL;
+		}
+	} while (ibuf_size(&rbuf) > 0);
+
+	if (ibuf_size(&rbuf) > 0)
+		memmove(msgbuf->rbuf, ibuf_data(&rbuf), ibuf_size(&rbuf));
+	msgbuf->roff = ibuf_size(&rbuf);
+
+	if (fd != -1)
+		close(fd);
 	return (1);
+
+ fail:
+	/* XXX how to properly clean up is unclear */
+	if (fd != -1)
+		close(fd);
+	return (-1);
 }
 
-uint32_t
-msgbuf_queuelen(struct msgbuf *msgbuf)
+int
+ibuf_read(int fd, struct msgbuf *msgbuf)
 {
-	return (msgbuf->queued);
+	struct iovec	iov;
+	ssize_t		n;
+
+	if (msgbuf->rbuf == NULL) {
+		errno = EINVAL;
+		return (-1);
+	}
+
+	iov.iov_base = msgbuf->rbuf + msgbuf->roff;
+	iov.iov_len = IBUF_READ_SIZE - msgbuf->roff;
+
+ again:
+	if ((n = readv(fd, &iov, 1)) == -1) {
+		if (errno == EINTR)
+			goto again;
+		if (errno == EAGAIN)
+			/* lets retry later again */
+			return (1);
+		return (-1);
+	}
+	if (n == 0)	/* connection closed */
+		return (0);
+
+	msgbuf->roff += n;
+	/* new data arrived, try to process it */
+	return (ibuf_read_process(msgbuf, -1));
 }
 
+int
+msgbuf_read(int fd, struct msgbuf *msgbuf)
+{
+	struct msghdr		 msg;
+	struct cmsghdr		*cmsg;
+	union {
+		struct cmsghdr hdr;
+		char	buf[CMSG_SPACE(sizeof(int) * 1)];
+	} cmsgbuf;
+	struct iovec		 iov;
+	ssize_t			 n;
+	int			 fdpass = -1;
+
+	if (msgbuf->rbuf == NULL) {
+		errno = EINVAL;
+		return (-1);
+	}
+
+	memset(&msg, 0, sizeof(msg));
+	memset(&cmsgbuf, 0, sizeof(cmsgbuf));
+
+	iov.iov_base = msgbuf->rbuf + msgbuf->roff;
+	iov.iov_len = IBUF_READ_SIZE - msgbuf->roff;
+	msg.msg_iov = &iov;
+	msg.msg_iovlen = 1;
+	msg.msg_control = &cmsgbuf.buf;
+	msg.msg_controllen = sizeof(cmsgbuf.buf);
+
+again:
+	if ((n = recvmsg(fd, &msg, 0)) == -1) {
+		if (errno == EINTR)
+			goto again;
+		if (errno == EMSGSIZE)
+			/*
+			 * Not enough fd slots: fd passing failed, retry
+			 * to receive the message without fd.
+			 * imsg_get_fd() will return -1 in that case.
+			 */
+			goto again;
+		if (errno == EAGAIN)
+			/* lets retry later again */
+			return (1);
+		return (-1);
+	}
+	if (n == 0)	/* connection closed */
+		return (0);
+
+	msgbuf->roff += 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, j, f;
+
+			/*
+			 * 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++) {
+				f = ((int *)CMSG_DATA(cmsg))[i];
+				if (i == 0)
+					fdpass = f;
+				else
+					close(f);
+			}
+		}
+		/* we do not handle other ctl data level */
+	}
+
+	/* new data arrived, try to process it */
+	return (ibuf_read_process(msgbuf, fdpass));
+}
+
 static void
-ibuf_enqueue(struct msgbuf *msgbuf, struct ibuf *buf)
+msgbuf_read_enqueue(struct msgbuf *msgbuf, struct ibuf *buf)
 {
-	if (buf->max == 0)	/* if buf lives on the stack */
-		abort();	/* abort before causing more harm */
+	/* if buf lives on the stack abort before causing more harm */
+	if (buf->fd == IBUF_FD_MARK_ON_STACK)
+		abort();
+	TAILQ_INSERT_TAIL(&msgbuf->rbufs, buf, entry);
+}
+
+static void
+msgbuf_enqueue(struct msgbuf *msgbuf, struct ibuf *buf)
+{
+	/* if buf lives on the stack abort before causing more harm */
+	if (buf->fd == IBUF_FD_MARK_ON_STACK)
+		abort();
 	TAILQ_INSERT_TAIL(&msgbuf->bufs, buf, entry);
 	msgbuf->queued++;
 }
 
 static void
-ibuf_dequeue(struct msgbuf *msgbuf, struct ibuf *buf)
+msgbuf_dequeue(struct msgbuf *msgbuf, struct ibuf *buf)
 {
 	TAILQ_REMOVE(&msgbuf->bufs, buf, entry);
 	msgbuf->queued--;
 	ibuf_free(buf);
 }
+
+static 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 (n >= ibuf_size(buf)) {
+			n -= ibuf_size(buf);
+			msgbuf_dequeue(msgbuf, buf);
+		} else {
+			buf->rpos += n;
+			n = 0;
+		}
+	}
+}
blob - c3eef13191d6fbcd0c647e47c1950afc53aa1619
blob + 43b5bd81cfb1257af33854e7a4e4a62c1a4d7cbf
--- compat/imsg.c
+++ compat/imsg.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: imsg.c,v 1.23 2023/12/12 15:47:41 claudio Exp $	*/
+/*	$OpenBSD: imsg.c,v 1.38 2024/11/29 04:35:13 tb Exp $	*/
 
 /*
  * Copyright (c) 2023 Claudio Jeker <claudio@openbsd.org>
@@ -24,164 +24,117 @@
 #include <sys/uio.h>
 
 #include <errno.h>
+#include <stddef.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
 #include "imsg.h"
 
-struct imsg_fd {
-	TAILQ_ENTRY(imsg_fd)	entry;
-	int			fd;
-};
+#define IMSG_ALLOW_FDPASS	0x01
+#define IMSG_FD_MARK		0x80000000U
 
-int	 imsg_fd_overhead = 0;
+static struct ibuf	*imsg_parse_hdr(struct ibuf *, void *, int *);
 
-static int	 imsg_dequeue_fd(struct imsgbuf *);
-
-void
-imsg_init(struct imsgbuf *imsgbuf, int fd)
+int
+imsgbuf_init(struct imsgbuf *imsgbuf, int fd)
 {
-	msgbuf_init(&imsgbuf->w);
-	memset(&imsgbuf->r, 0, sizeof(imsgbuf->r));
-	imsgbuf->fd = fd;
-	imsgbuf->w.fd = fd;
+	imsgbuf->w = msgbuf_new_reader(IMSG_HEADER_SIZE, imsg_parse_hdr,
+	    imsgbuf);
+	if (imsgbuf->w == NULL)
+		return (-1);
 	imsgbuf->pid = getpid();
-	TAILQ_INIT(&imsgbuf->fds);
+	imsgbuf->maxsize = MAX_IMSGSIZE;
+	imsgbuf->fd = fd;
+	imsgbuf->flags = 0;
+	return (0);
 }
 
-ssize_t
-imsg_read(struct imsgbuf *imsgbuf)
+void
+imsgbuf_allow_fdpass(struct imsgbuf *imsgbuf)
 {
-	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;
+	imsgbuf->flags |= IMSG_ALLOW_FDPASS;
+}
 
-	memset(&msg, 0, sizeof(msg));
-	memset(&cmsgbuf, 0, sizeof(cmsgbuf));
-
-	iov.iov_base = imsgbuf->r.buf + imsgbuf->r.wpos;
-	iov.iov_len = sizeof(imsgbuf->r.buf) - imsgbuf->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)
+int
+imsgbuf_set_maxsize(struct imsgbuf *imsgbuf, uint32_t maxsize)
+{
+	if (maxsize < IMSG_HEADER_SIZE || maxsize & IMSG_FD_MARK) {
+		errno = EINVAL;
 		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);
 	}
+	imsgbuf->maxsize = maxsize;
+	return (0);
+}
 
-	if ((n = recvmsg(imsgbuf->fd, &msg, 0)) == -1) {
-		if (errno == EINTR)
-			goto again;
-		goto fail;
-	}
+int
+imsgbuf_read(struct imsgbuf *imsgbuf)
+{
+	if (imsgbuf->flags & IMSG_ALLOW_FDPASS)
+		return msgbuf_read(imsgbuf->fd, imsgbuf->w);
+	else
+		return ibuf_read(imsgbuf->fd, imsgbuf->w);
+}
 
-	imsgbuf->r.wpos += n;
+int
+imsgbuf_write(struct imsgbuf *imsgbuf)
+{
+	if (imsgbuf->flags & IMSG_ALLOW_FDPASS)
+		return msgbuf_write(imsgbuf->fd, imsgbuf->w);
+	else
+		return ibuf_write(imsgbuf->fd, imsgbuf->w);
+}
 
-	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(&imsgbuf->fds, ifd,
-					    entry);
-					ifd = NULL;
-				} else
-					close(fd);
-			}
-		}
-		/* we do not handle other ctl data level */
+int
+imsgbuf_flush(struct imsgbuf *imsgbuf)
+{
+	while (imsgbuf_queuelen(imsgbuf) > 0) {
+		if (imsgbuf_write(imsgbuf) == -1)
+			return (-1);
 	}
+	return (0);
+}
 
-fail:
-	free(ifd);
-	return (n);
+void
+imsgbuf_clear(struct imsgbuf *imsgbuf)
+{
+	msgbuf_free(imsgbuf->w);
+	imsgbuf->w = NULL;
 }
 
+uint32_t
+imsgbuf_queuelen(struct imsgbuf *imsgbuf)
+{
+	return msgbuf_queuelen(imsgbuf->w);
+}
+
 ssize_t
 imsg_get(struct imsgbuf *imsgbuf, struct imsg *imsg)
 {
 	struct imsg		 m;
-	size_t			 av, left, datalen;
+	struct ibuf		*buf;
 
-	av = imsgbuf->r.wpos;
-
-	if (IMSG_HEADER_SIZE > av)
+	if ((buf = msgbuf_get(imsgbuf->w)) == NULL)
 		return (0);
 
-	memcpy(&m.hdr, imsgbuf->r.buf, sizeof(m.hdr));
-	if (m.hdr.len < IMSG_HEADER_SIZE ||
-	    m.hdr.len > MAX_IMSGSIZE) {
-		errno = ERANGE;
+	if (ibuf_get(buf, &m.hdr, sizeof(m.hdr)) == -1)
 		return (-1);
-	}
-	if (m.hdr.len > av)
-		return (0);
 
-	m.fd = -1;
-	m.buf = NULL;
-	m.data = NULL;
+	if (ibuf_size(buf))
+		m.data = ibuf_data(buf);
+	else
+		m.data = NULL;
+	m.buf = buf;
+	m.hdr.len &= ~IMSG_FD_MARK;
 
-	datalen = m.hdr.len - IMSG_HEADER_SIZE;
-	imsgbuf->r.rptr = imsgbuf->r.buf + IMSG_HEADER_SIZE;
-	if (datalen != 0) {
-		if ((m.buf = ibuf_open(datalen)) == NULL)
-			return (-1);
-		if (ibuf_add(m.buf, imsgbuf->r.rptr, datalen) == -1) {
-			/* this should never fail */
-			ibuf_free(m.buf);
-			return (-1);
-		}
-		m.data = ibuf_data(m.buf);
-	}
-
-	if (m.hdr.flags & IMSGF_HASFD)
-		m.fd = imsg_dequeue_fd(imsgbuf);
-
-	if (m.hdr.len < av) {
-		left = av - m.hdr.len;
-		memmove(&imsgbuf->r.buf, imsgbuf->r.buf + m.hdr.len, left);
-		imsgbuf->r.wpos = left;
-	} else
-		imsgbuf->r.wpos = 0;
-
 	*imsg = m;
-	return (datalen + IMSG_HEADER_SIZE);
+	return (ibuf_size(buf) + IMSG_HEADER_SIZE);
 }
 
 int
 imsg_get_ibuf(struct imsg *imsg, struct ibuf *ibuf)
 {
-	if (imsg->buf == NULL) {
+	if (ibuf_size(imsg->buf) == 0) {
 		errno = EBADMSG;
 		return (-1);
 	}
@@ -195,7 +148,7 @@ imsg_get_data(struct imsg *imsg, void *data, size_t le
 		errno = EINVAL;
 		return (-1);
 	}
-	if (imsg->buf == NULL || ibuf_size(imsg->buf) != len) {
+	if (ibuf_size(imsg->buf) != len) {
 		errno = EBADMSG;
 		return (-1);
 	}
@@ -205,10 +158,7 @@ imsg_get_data(struct imsg *imsg, void *data, size_t le
 int
 imsg_get_fd(struct imsg *imsg)
 {
-	int fd = imsg->fd;
-
-	imsg->fd = -1;
-	return fd;
+	return ibuf_fd_get(imsg->buf);
 }
 
 uint32_t
@@ -220,8 +170,6 @@ imsg_get_id(struct imsg *imsg)
 size_t
 imsg_get_len(struct imsg *imsg)
 {
-	if (imsg->buf == NULL)
-		return 0;
 	return ibuf_size(imsg->buf);
 }
 
@@ -291,14 +239,13 @@ imsg_compose_ibuf(struct imsgbuf *imsgbuf, uint32_t ty
 	struct imsg_hdr	 hdr;
 	int save_errno;
 
-	if (ibuf_size(buf) + IMSG_HEADER_SIZE > MAX_IMSGSIZE) {
+	if (ibuf_size(buf) + IMSG_HEADER_SIZE > imsgbuf->maxsize) {
 		errno = ERANGE;
 		goto fail;
 	}
 
 	hdr.type = type;
 	hdr.len = ibuf_size(buf) + IMSG_HEADER_SIZE;
-	hdr.flags = 0;
 	hdr.peerid = id;
 	if ((hdr.pid = pid) == 0)
 		hdr.pid = imsgbuf->pid;
@@ -308,8 +255,8 @@ imsg_compose_ibuf(struct imsgbuf *imsgbuf, uint32_t ty
 	if (imsg_add(hdrbuf, &hdr, sizeof(hdr)) == -1)
 		goto fail;
 
-	ibuf_close(&imsgbuf->w, hdrbuf);
-	ibuf_close(&imsgbuf->w, buf);
+	ibuf_close(imsgbuf->w, hdrbuf);
+	ibuf_close(imsgbuf->w, buf);
 	return (1);
 
  fail:
@@ -327,24 +274,18 @@ int
 imsg_forward(struct imsgbuf *imsgbuf, struct imsg *msg)
 {
 	struct ibuf	*wbuf;
-	size_t		 len = 0;
+	size_t		 len;
 
-	if (msg->fd != -1) {
-		close(msg->fd);
-		msg->fd = -1;
-	}
+	ibuf_rewind(msg->buf);
+	ibuf_skip(msg->buf, sizeof(msg->hdr));
+	len = ibuf_size(msg->buf);
 
-	if (msg->buf != NULL) {
-		ibuf_rewind(msg->buf);
-		len = ibuf_size(msg->buf);
-	}
-
 	if ((wbuf = imsg_create(imsgbuf, msg->hdr.type, msg->hdr.peerid,
 	    msg->hdr.pid, len)) == NULL)
 		return (-1);
 
-	if (msg->buf != NULL) {
-		if (ibuf_add_buf(wbuf, msg->buf) == -1) {
+	if (len != 0) {
+		if (ibuf_add_ibuf(wbuf, msg->buf) == -1) {
 			ibuf_free(wbuf);
 			return (-1);
 		}
@@ -362,17 +303,16 @@ imsg_create(struct imsgbuf *imsgbuf, uint32_t type, ui
 	struct imsg_hdr	 hdr;
 
 	datalen += IMSG_HEADER_SIZE;
-	if (datalen > MAX_IMSGSIZE) {
+	if (datalen > imsgbuf->maxsize) {
 		errno = ERANGE;
 		return (NULL);
 	}
 
 	hdr.type = type;
-	hdr.flags = 0;
 	hdr.peerid = id;
 	if ((hdr.pid = pid) == 0)
 		hdr.pid = imsgbuf->pid;
-	if ((wbuf = ibuf_dynamic(datalen, MAX_IMSGSIZE)) == NULL) {
+	if ((wbuf = ibuf_dynamic(datalen, imsgbuf->maxsize)) == NULL) {
 		return (NULL);
 	}
 	if (imsg_add(wbuf, &hdr, sizeof(hdr)) == -1)
@@ -395,16 +335,13 @@ imsg_add(struct ibuf *msg, const void *data, size_t da
 void
 imsg_close(struct imsgbuf *imsgbuf, struct ibuf *msg)
 {
-	struct imsg_hdr	*hdr;
+	uint32_t len;
 
-	hdr = (struct imsg_hdr *)msg->buf;
-
-	hdr->flags &= ~IMSGF_HASFD;
+	len = ibuf_size(msg);
 	if (ibuf_fd_avail(msg))
-		hdr->flags |= IMSGF_HASFD;
-	hdr->len = ibuf_size(msg);
-
-	ibuf_close(&imsgbuf->w, msg);
+		len |= IMSG_FD_MARK;
+	(void)ibuf_set_h32(msg, offsetof(struct imsg_hdr, len), len);
+	ibuf_close(imsgbuf->w, msg);
 }
 
 void
@@ -413,37 +350,29 @@ imsg_free(struct imsg *imsg)
 	ibuf_free(imsg->buf);
 }
 
-static int
-imsg_dequeue_fd(struct imsgbuf *imsgbuf)
+static struct ibuf *
+imsg_parse_hdr(struct ibuf *buf, void *arg, int *fd)
 {
-	int		 fd;
-	struct imsg_fd	*ifd;
+	struct imsgbuf *imsgbuf = arg;
+	struct imsg_hdr hdr;
+	struct ibuf *b;
+	uint32_t len;
 
-	if ((ifd = TAILQ_FIRST(&imsgbuf->fds)) == NULL)
-		return (-1);
+	if (ibuf_get(buf, &hdr, sizeof(hdr)) == -1)
+		return (NULL);
 
-	fd = ifd->fd;
-	TAILQ_REMOVE(&imsgbuf->fds, ifd, entry);
-	free(ifd);
+	len = hdr.len & ~IMSG_FD_MARK;
 
-	return (fd);
-}
+	if (len < IMSG_HEADER_SIZE || len > imsgbuf->maxsize) {
+		errno = ERANGE;
+		return (NULL);
+	}
+	if ((b = ibuf_open(len)) == NULL)
+		return (NULL);
+	if (hdr.len & IMSG_FD_MARK) {
+		ibuf_fd_set(b, *fd);
+		*fd = -1;
+	}
 
-int
-imsg_flush(struct imsgbuf *imsgbuf)
-{
-	while (imsgbuf->w.queued)
-		if (msgbuf_write(&imsgbuf->w) <= 0)
-			return (-1);
-	return (0);
+	return b;
 }
-
-void
-imsg_clear(struct imsgbuf *imsgbuf)
-{
-	int	fd;
-
-	msgbuf_clear(&imsgbuf->w);
-	while ((fd = imsg_dequeue_fd(imsgbuf)) != -1)
-		close(fd);
-}
blob - dd47b1889da577ce63769035f0e4bd0b1d8a7c32
blob + f70ff098cf3f4d650bf9896ceaca431a88f28bea
--- compat/imsg.h
+++ compat/imsg.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: imsg.h,v 1.8 2023/12/12 15:47:41 claudio Exp $	*/
+/*	$OpenBSD: imsg.h,v 1.19 2024/11/26 13:57:31 claudio Exp $	*/
 
 /*
  * Copyright (c) 2023 Claudio Jeker <claudio@openbsd.org>
@@ -23,6 +23,7 @@
 #define _IMSG_H_
 
 #include <sys/types.h>
+#include <stdint.h>
 
 #define IBUF_READ_SIZE		65535
 #define IMSG_HEADER_SIZE	sizeof(struct imsg_hdr)
@@ -38,40 +39,25 @@ struct ibuf {
 	int			 fd;
 };
 
-struct msgbuf {
-	TAILQ_HEAD(, ibuf)	 bufs;
-	uint32_t		 queued;
-	int			 fd;
-};
+struct msgbuf;
 
-struct ibuf_read {
-	unsigned char		 buf[IBUF_READ_SIZE];
-	unsigned char		*rptr;
-	size_t			 wpos;
-};
-
-struct imsg_fd;
 struct imsgbuf {
-	TAILQ_HEAD(, imsg_fd)	 fds;
-	struct ibuf_read	 r;
-	struct msgbuf		 w;
-	int			 fd;
+	struct msgbuf		*w;
 	pid_t			 pid;
+	uint32_t		 maxsize;
+	int			 fd;
+	int			 flags;
 };
 
-#define IMSGF_HASFD	1
-
 struct imsg_hdr {
 	uint32_t	 type;
-	uint16_t	 len;
-	uint16_t	 flags;
+	uint32_t	 len;
 	uint32_t	 peerid;
 	uint32_t	 pid;
 };
 
 struct imsg {
 	struct imsg_hdr	 hdr;
-	int		 fd;
 	void		*data;
 	struct ibuf	*buf;
 };
@@ -82,7 +68,6 @@ struct iovec;
 struct ibuf	*ibuf_open(size_t);
 struct ibuf	*ibuf_dynamic(size_t, size_t);
 int		 ibuf_add(struct ibuf *, const void *, size_t);
-int		 ibuf_add_buf(struct ibuf *, const struct ibuf *);
 int		 ibuf_add_ibuf(struct ibuf *, const struct ibuf *);
 int		 ibuf_add_zero(struct ibuf *, size_t);
 int		 ibuf_add_n8(struct ibuf *, uint64_t);
@@ -119,20 +104,33 @@ int		 ibuf_get_n64(struct ibuf *, uint64_t *);
 int		 ibuf_get_h16(struct ibuf *, uint16_t *);
 int		 ibuf_get_h32(struct ibuf *, uint32_t *);
 int		 ibuf_get_h64(struct ibuf *, uint64_t *);
+char		*ibuf_get_string(struct ibuf *, size_t);
 int		 ibuf_skip(struct ibuf *, size_t);
 void		 ibuf_free(struct ibuf *);
 int		 ibuf_fd_avail(struct ibuf *);
 int		 ibuf_fd_get(struct ibuf *);
 void		 ibuf_fd_set(struct ibuf *, int);
-int		 ibuf_write(struct msgbuf *);
-void		 msgbuf_init(struct msgbuf *);
+struct msgbuf	*msgbuf_new(void);
+struct msgbuf	*msgbuf_new_reader(size_t,
+		    struct ibuf *(*)(struct ibuf *, void *, int *), void *);
+void		 msgbuf_free(struct msgbuf *);
 void		 msgbuf_clear(struct msgbuf *);
 uint32_t	 msgbuf_queuelen(struct msgbuf *);
-int		 msgbuf_write(struct msgbuf *);
+int		 ibuf_write(int, struct msgbuf *);
+int		 msgbuf_write(int, struct msgbuf *);
+int		 ibuf_read(int, struct msgbuf *);
+int		 msgbuf_read(int, struct msgbuf *);
+struct ibuf	*msgbuf_get(struct msgbuf *);
 
 /* imsg.c */
-void	 imsg_init(struct imsgbuf *, int);
-ssize_t	 imsg_read(struct imsgbuf *);
+int	 imsgbuf_init(struct imsgbuf *, int);
+void	 imsgbuf_allow_fdpass(struct imsgbuf *imsgbuf);
+int	 imsgbuf_set_maxsize(struct imsgbuf *, uint32_t);
+int	 imsgbuf_read(struct imsgbuf *);
+int	 imsgbuf_write(struct imsgbuf *);
+int	 imsgbuf_flush(struct imsgbuf *);
+void	 imsgbuf_clear(struct imsgbuf *);
+uint32_t imsgbuf_queuelen(struct imsgbuf *);
 ssize_t	 imsg_get(struct imsgbuf *, struct imsg *);
 int	 imsg_get_ibuf(struct imsg *, struct ibuf *);
 int	 imsg_get_data(struct imsg *, void *, size_t);
@@ -152,7 +150,5 @@ struct ibuf *imsg_create(struct imsgbuf *, uint32_t, u
 int	 imsg_add(struct ibuf *, const void *, size_t);
 void	 imsg_close(struct imsgbuf *, struct ibuf *);
 void	 imsg_free(struct imsg *);
-int	 imsg_flush(struct imsgbuf *);
-void	 imsg_clear(struct imsgbuf *);
 
 #endif
blob - e1fb2593da4a23e14b1488dd774cc0d7cb259b44
blob + 2da1175b68c31e2b9f572288f297455ed0b351c8
--- configure.ac
+++ configure.ac
@@ -202,7 +202,7 @@ AS_IF([test "x$with_libimsg" = "xyes"], [
 	])
 ])
 
-AC_SEARCH_LIBS([imsg_init], [util], [
+AC_SEARCH_LIBS([imsgbuf_init], [util], [
 		AC_DEFINE([HAVE_IMSG], 1,
 			[Define to 1 if you have imsg functions (-lutil or -limsg).])
 	], [
blob - 65a705971ea2f9a254dbf0dcbf208401bd9e2d2d
blob + d1d426e94792797943f3b3dc0400351c91133ce0
--- control.c
+++ control.c
@@ -155,7 +155,13 @@ control_accept(int listenfd, int event, void *bula)
 
 	c = xcalloc(1, sizeof(struct ctl_conn));
 
-	imsg_init(&c->iev.ibuf, connfd);
+	if (imsgbuf_init(&c->iev.ibuf, connfd) == -1) {
+		message("%s: ev_add: %s", __func__, strerror(errno));
+		close(connfd);
+		free(c);
+		return;
+	}
+
 	c->iev.handler = control_dispatch_imsg;
 	c->iev.events = EV_READ;
 	if (ev_add(connfd, c->iev.events, c->iev.handler, &c->iev) == -1) {
@@ -204,20 +210,20 @@ control_close(int fd)
 		return;
 	}
 
-	msgbuf_clear(&c->iev.ibuf.w);
-	TAILQ_REMOVE(&ctl_conns, c, entry);
-
 	ev_del(c->iev.ibuf.fd);
 	close(c->iev.ibuf.fd);
 
+	imsgbuf_clear(&c->iev.ibuf);
+	TAILQ_REMOVE(&ctl_conns, c, entry);
+
+	free(c);
+
 	/* Some file descriptors are available again. */
 	if (ev_timer_pending(control_state.timeout)) {
 		ev_timer_cancel(control_state.timeout);
 		control_state.timeout = 0;
 		ev_add(control_state.fd, EV_READ, control_accept, NULL);
 	}
-
-	free(c);
 }
 
 void
@@ -233,14 +239,13 @@ control_dispatch_imsg(int fd, int event, void *bula)
 	}
 
 	if (event & EV_READ) {
-		if (((n = imsg_read(&c->iev.ibuf)) == -1 && errno != EAGAIN) ||
-		    n == 0) {
+		if (imsgbuf_read(&c->iev.ibuf) == -1) {
 			control_close(fd);
 			return;
 		}
 	}
 	if (event & EV_WRITE) {
-		if (msgbuf_write(&c->iev.ibuf.w) <= 0 && errno != EAGAIN) {
+		if (imsgbuf_write(&c->iev.ibuf) == -1) {
 			control_close(fd);
 			return;
 		}
blob - 1680c011fd08a77fc6d0009ed020c48efded8de1
blob + 1a27057eb0bff3416cb1b75a3360435db1e4a48c
--- imsgev.c
+++ imsgev.c
@@ -23,7 +23,7 @@ void
 imsg_event_add(struct imsgev *iev)
 {
 	iev->events = EV_READ;
-	if (iev->ibuf.w.queued)
+	if (imsgbuf_queuelen(&iev->ibuf))
 		iev->events |= EV_WRITE;
 
 	ev_add(iev->ibuf.fd, iev->events, iev->handler, iev);
blob - b4095c8a50f78adc731e74dcccb649ed864cd84b
blob + 64c2e4414394dca4cfc2e4d7e1c6f3b709ba1ad4
--- net.c
+++ net.c
@@ -580,16 +580,16 @@ handle_dispatch_imsg(int fd, int event, void *d)
 	int		 certok;
 
 	if (event & EV_READ) {
-		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
-			err(1, "imsg_read");
-		if (n == 0)
-			err(1, "connection closed");
+		if (imsgbuf_read(ibuf) == -1) {
+			if (errno == EPIPE)
+				errx(1, "connection closed");
+			else
+				err(1, "imsg_read failure");
+		}
 	}
 	if (event & EV_WRITE) {
-		if ((n = msgbuf_write(&ibuf->w)) == -1 && errno != EAGAIN)
+		if (imsgbuf_write(ibuf) == -1 && errno != EAGAIN)
 			err(1, "msgbuf_write");
-		if (n == 0)
-			err(1, "connection closed");
 	}
 
 	for (;;) {
@@ -704,7 +704,8 @@ net_main(void)
 
 	/* Setup pipe and event handler to the main process */
 	iev_ui = xmalloc(sizeof(*iev_ui));
-	imsg_init(&iev_ui->ibuf, 3);
+	if (imsgbuf_init(&iev_ui->ibuf, 3) == -1)
+		err(1, "imsgbuf_init failed");
 	iev_ui->handler = handle_dispatch_imsg;
 	iev_ui->events = EV_READ;
 	ev_add(iev_ui->ibuf.fd, iev_ui->events, iev_ui->handler, iev_ui);
@@ -713,7 +714,7 @@ net_main(void)
 
 	ev_loop();
 
-	msgbuf_clear(&iev_ui->ibuf.w);
+	imsgbuf_clear(&iev_ui->ibuf);
 	close(iev_ui->ibuf.fd);
 	free(iev_ui);
 
blob - d1be335dfcb0919299d8afa13e11cc06d75f77b9
blob + 3bb3d2b7cef512ba92a8ebc66c68f715f9e0d42b
--- telescope.c
+++ telescope.c
@@ -457,16 +457,12 @@ handle_dispatch_imsg(int fd, int event, void *data)
 	int		 code;
 
 	if (event & EV_READ) {
-		if ((n = imsg_read(imsgbuf)) == -1 && errno != EAGAIN)
+		if (imsgbuf_read(imsgbuf) == -1)
 			err(1, "imsg_read");
-		if (n == 0)
-			err(1, "connection closed");
 	}
 	if (event & EV_WRITE) {
-		if ((n = msgbuf_write(&imsgbuf->w)) == -1 && errno != EAGAIN)
+		if (imsgbuf_write(imsgbuf) == -1)
 			err(1, "msgbuf_write");
-		if (n == 0)
-			err(1, "connection closed");
 	}
 
 	for (;;) {
@@ -1052,10 +1048,11 @@ send_url(const char *url)
 	if (connect(ctl_sock, (struct sockaddr *)&sun, sizeof(sun)) == -1)
 		err(1, "connect: %s", ctlsock_path);
 
-	imsg_init(&ibuf, ctl_sock);
+	if (imsgbuf_init(&ibuf, ctl_sock) == -1)
+		err(1, "imsgbuf_init");
 	imsg_compose(&ibuf, IMSG_CTL_OPEN_URL, 0, 0, -1, url,
 	    strlen(url) + 1);
-	imsg_flush(&ibuf);
+	imsgbuf_flush(&ibuf);
 	close(ctl_sock);
 }
 
@@ -1192,7 +1189,8 @@ main(int argc, char * const *argv)
 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe2net) == -1)
 		err(1, "socketpair");
 	start_child(PROC_NET, argv0, pipe2net[1]);
-	imsg_init(&net_ibuf.ibuf, pipe2net[0]);
+	if (imsgbuf_init(&net_ibuf.ibuf, pipe2net[0]) == -1)
+		err(1, "imsgbuf_init");
 	iev_net = &net_ibuf;
 	iev_net->handler = handle_dispatch_imsg;
 
@@ -1232,7 +1230,7 @@ main(int argc, char * const *argv)
 	}
 
 	ui_send_net(IMSG_QUIT, 0, -1, NULL, 0);
-	imsg_flush(&iev_net->ibuf);
+	imsgbuf_flush(&iev_net->ibuf);
 
 	/* wait for children to terminate */
 	do {