Update imsg.

compat/imsg-buffer.c

@@ -1,6 +1,7 @@
-/*	$OpenBSD: imsg-buffer.c,v 1.12 2019/01/20 02:50:03 bcook Exp $	*/
+/*	$OpenBSD: imsg-buffer.c,v 1.18 2023/12/12 15:47:41 claudio Exp $	*/
 
 /*
+ * Copyright (c) 2023 Claudio Jeker <claudio@openbsd.org>
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
  *
  * Permission to use, copy, modify, and distribute this software for any
@@ -22,6 +23,8 @@
 
 #include <limits.h>
 #include <errno.h>
+#include <endian.h>
+#include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
@@ -32,15 +35,20 @@
 static int	ibuf_realloc(struct ibuf *, size_t);
 static void	ibuf_enqueue(struct msgbuf *, struct ibuf *);
 static void	ibuf_dequeue(struct msgbuf *, struct ibuf *);
+static void	msgbuf_drain(struct msgbuf *, size_t);
 
 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 = malloc(len)) == NULL) {
+	if ((buf->buf = calloc(len, 1)) == NULL) {
 		free(buf);
 		return (NULL);
 	}
@@ -55,14 +63,22 @@ ibuf_dynamic(size_t len, size_t max)
 {
 	struct ibuf	*buf;
 
-	if (max < len)
+	if (max == 0 || max < len) {
+		errno = EINVAL;
 		return (NULL);
+	}
 
-	if ((buf = ibuf_open(len)) == NULL)
+	if ((buf = calloc(1, sizeof(struct ibuf))) == NULL)
 		return (NULL);
-
-	if (max > 0)
-		buf->max = max;
+	if (len > 0) {
+		if ((buf->buf = calloc(len, 1)) == NULL) {
+			free(buf);
+			return (NULL);
+		}
+	}
+	buf->size = len;
+	buf->max = max;
+	buf->fd = -1;
 
 	return (buf);
 }
@@ -73,7 +89,7 @@ ibuf_realloc(struct ibuf *buf, size_t len)
 	unsigned char	*b;
 
 	/* on static buffers max is eq size and so the following fails */
-	if (buf->wpos + len > buf->max) {
+	if (len > SIZE_MAX - buf->wpos || buf->wpos + len > buf->max) {
 		errno = ERANGE;
 		return (-1);
 	}
@@ -87,23 +103,16 @@ ibuf_realloc(struct ibuf *buf, size_t 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 (len > SIZE_MAX - buf->wpos || buf->max == 0) {
+		errno = ERANGE;
+		return (NULL);
+	}
+
 	if (buf->wpos + len > buf->size)
 		if (ibuf_realloc(buf, len) == -1)
 			return (NULL);
@@ -113,34 +122,416 @@ ibuf_reserve(struct ibuf *buf, size_t len)
 	return (b);
 }
 
+int
+ibuf_add(struct ibuf *buf, const void *data, size_t len)
+{
+	void *b;
+
+	if ((b = ibuf_reserve(buf, len)) == NULL)
+		return (-1);
+
+	memcpy(b, data, len);
+	return (0);
+}
+
+int
+ibuf_add_ibuf(struct ibuf *buf, const struct ibuf *from)
+{
+	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;
+
+	if (value > UINT8_MAX) {
+		errno = EINVAL;
+		return (-1);
+	}
+	v = value;
+	return ibuf_add(buf, &v, sizeof(v));
+}
+
+int
+ibuf_add_n16(struct ibuf *buf, uint64_t value)
+{
+	uint16_t v;
+
+	if (value > UINT16_MAX) {
+		errno = EINVAL;
+		return (-1);
+	}
+	v = htobe16(value);
+	return ibuf_add(buf, &v, sizeof(v));
+}
+
+int
+ibuf_add_n32(struct ibuf *buf, uint64_t value)
+{
+	uint32_t v;
+
+	if (value > UINT32_MAX) {
+		errno = EINVAL;
+		return (-1);
+	}
+	v = htobe32(value);
+	return ibuf_add(buf, &v, sizeof(v));
+}
+
+int
+ibuf_add_n64(struct ibuf *buf, uint64_t value)
+{
+	value = htobe64(value);
+	return ibuf_add(buf, &value, sizeof(value));
+}
+
+int
+ibuf_add_h16(struct ibuf *buf, uint64_t value)
+{
+	uint16_t v;
+
+	if (value > UINT16_MAX) {
+		errno = EINVAL;
+		return (-1);
+	}
+	v = value;
+	return ibuf_add(buf, &v, sizeof(v));
+}
+
+int
+ibuf_add_h32(struct ibuf *buf, uint64_t value)
+{
+	uint32_t v;
+
+	if (value > UINT32_MAX) {
+		errno = EINVAL;
+		return (-1);
+	}
+	v = value;
+	return ibuf_add(buf, &v, sizeof(v));
+}
+
+int
+ibuf_add_h64(struct ibuf *buf, uint64_t value)
+{
+	return ibuf_add(buf, &value, sizeof(value));
+}
+
+int
+ibuf_add_zero(struct ibuf *buf, size_t len)
+{
+	void *b;
+
+	if ((b = ibuf_reserve(buf, len)) == NULL)
+		return (-1);
+	memset(b, 0, len);
+	return (0);
+}
+
 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)
+	/* only allow seeking between rpos and wpos */
+	if (ibuf_size(buf) < pos || SIZE_MAX - pos < len ||
+	    ibuf_size(buf) < pos + len) {
+		errno = ERANGE;
 		return (NULL);
+	}
 
-	return (buf->buf + pos);
+	return (buf->buf + buf->rpos + pos);
+}
+
+int
+ibuf_set(struct ibuf *buf, size_t pos, const void *data, size_t len)
+{
+	void *b;
+
+	if ((b = ibuf_seek(buf, pos, len)) == NULL)
+		return (-1);
+
+	memcpy(b, data, len);
+	return (0);
+}
+
+int
+ibuf_set_n8(struct ibuf *buf, size_t pos, uint64_t value)
+{
+	uint8_t v;
+
+	if (value > UINT8_MAX) {
+		errno = EINVAL;
+		return (-1);
+	}
+	v = value;
+	return (ibuf_set(buf, pos, &v, sizeof(v)));
+}
+
+int
+ibuf_set_n16(struct ibuf *buf, size_t pos, uint64_t value)
+{
+	uint16_t v;
+
+	if (value > UINT16_MAX) {
+		errno = EINVAL;
+		return (-1);
+	}
+	v = htobe16(value);
+	return (ibuf_set(buf, pos, &v, sizeof(v)));
+}
+
+int
+ibuf_set_n32(struct ibuf *buf, size_t pos, uint64_t value)
+{
+	uint32_t v;
+
+	if (value > UINT32_MAX) {
+		errno = EINVAL;
+		return (-1);
+	}
+	v = htobe32(value);
+	return (ibuf_set(buf, pos, &v, sizeof(v)));
+}
+
+int
+ibuf_set_n64(struct ibuf *buf, size_t pos, uint64_t value)
+{
+	value = htobe64(value);
+	return (ibuf_set(buf, pos, &value, sizeof(value)));
+}
+
+int
+ibuf_set_h16(struct ibuf *buf, size_t pos, uint64_t value)
+{
+	uint16_t v;
+
+	if (value > UINT16_MAX) {
+		errno = EINVAL;
+		return (-1);
+	}
+	v = value;
+	return (ibuf_set(buf, pos, &v, sizeof(v)));
+}
+
+int
+ibuf_set_h32(struct ibuf *buf, size_t pos, uint64_t value)
+{
+	uint32_t v;
+
+	if (value > UINT32_MAX) {
+		errno = EINVAL;
+		return (-1);
+	}
+	v = value;
+	return (ibuf_set(buf, pos, &v, sizeof(v)));
+}
+
+int
+ibuf_set_h64(struct ibuf *buf, size_t pos, uint64_t value)
+{
+	return (ibuf_set(buf, pos, &value, sizeof(value)));
+}
+
+void *
+ibuf_data(const struct ibuf *buf)
+{
+	return (buf->buf + buf->rpos);
 }
 
 size_t
-ibuf_size(struct ibuf *buf)
+ibuf_size(const struct ibuf *buf)
 {
-	return (buf->wpos);
+	return (buf->wpos - buf->rpos);
 }
 
 size_t
-ibuf_left(struct ibuf *buf)
+ibuf_left(const struct ibuf *buf)
 {
+	if (buf->max == 0)
+		return (0);
 	return (buf->max - buf->wpos);
 }
 
+int
+ibuf_truncate(struct ibuf *buf, size_t len)
+{
+	if (ibuf_size(buf) >= len) {
+		buf->wpos = buf->rpos + len;
+		return (0);
+	}
+	if (buf->max == 0) {
+		/* only allow to truncate down */
+		errno = ERANGE;
+		return (-1);
+	}
+	return ibuf_add_zero(buf, len - ibuf_size(buf));
+}
+
+void
+ibuf_rewind(struct ibuf *buf)
+{
+	buf->rpos = 0;
+}
+
 void
 ibuf_close(struct msgbuf *msgbuf, struct ibuf *buf)
 {
 	ibuf_enqueue(msgbuf, buf);
 }
 
+void
+ibuf_from_buffer(struct ibuf *buf, void *data, size_t len)
+{
+	memset(buf, 0, sizeof(*buf));
+	buf->buf = data;
+	buf->size = buf->wpos = len;
+	buf->fd = -1;
+}
+
+void
+ibuf_from_ibuf(struct ibuf *buf, const struct ibuf *from)
+{
+	ibuf_from_buffer(buf, ibuf_data(from), ibuf_size(from));
+}
+
+int
+ibuf_get(struct ibuf *buf, void *data, size_t len)
+{
+	if (ibuf_size(buf) < len) {
+		errno = EBADMSG;
+		return (-1);
+	}
+
+	memcpy(data, ibuf_data(buf), len);
+	buf->rpos += len;
+	return (0);
+}
+
+int
+ibuf_get_ibuf(struct ibuf *buf, size_t len, struct ibuf *new)
+{
+	if (ibuf_size(buf) < len) {
+		errno = EBADMSG;
+		return (-1);
+	}
+
+	ibuf_from_buffer(new, ibuf_data(buf), len);
+	buf->rpos += len;
+	return (0);
+}
+
+int
+ibuf_get_n8(struct ibuf *buf, uint8_t *value)
+{
+	return ibuf_get(buf, value, sizeof(*value));
+}
+
+int
+ibuf_get_n16(struct ibuf *buf, uint16_t *value)
+{
+	int rv;
+
+	rv = ibuf_get(buf, value, sizeof(*value));
+	*value = be16toh(*value);
+	return (rv);
+}
+
+int
+ibuf_get_n32(struct ibuf *buf, uint32_t *value)
+{
+	int rv;
+
+	rv = ibuf_get(buf, value, sizeof(*value));
+	*value = be32toh(*value);
+	return (rv);
+}
+
+int
+ibuf_get_n64(struct ibuf *buf, uint64_t *value)
+{
+	int rv;
+
+	rv = ibuf_get(buf, value, sizeof(*value));
+	*value = be64toh(*value);
+	return (rv);
+}
+
+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_skip(struct ibuf *buf, size_t len)
+{
+	if (ibuf_size(buf) < len) {
+		errno = EBADMSG;
+		return (-1);
+	}
+
+	buf->rpos += len;
+	return (0);
+}
+
+void
+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)
+		close(buf->fd);
+	freezero(buf->buf, buf->size);
+	free(buf);
+}
+
+int
+ibuf_fd_avail(struct ibuf *buf)
+{
+	return (buf->fd != -1);
+}
+
+int
+ibuf_fd_get(struct ibuf *buf)
+{
+	int fd;
+
+	fd = buf->fd;
+	buf->fd = -1;
+	return (fd);
+}
+
+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)
+		close(buf->fd);
+	buf->fd = fd;
+}
+
 int
 ibuf_write(struct msgbuf *msgbuf)
 {
@@ -153,8 +544,8 @@ ibuf_write(struct msgbuf *msgbuf)
 	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;
+		iov[i].iov_base = ibuf_data(buf);
+		iov[i].iov_len = ibuf_size(buf);
 		i++;
 	}
 
@@ -177,15 +568,6 @@ again:
 	return (1);
 }
 
-void
-ibuf_free(struct ibuf *buf)
-{
-	if (buf == NULL)
-		return;
-	freezero(buf->buf, buf->size);
-	free(buf);
-}
-
 void
 msgbuf_init(struct msgbuf *msgbuf)
 {
@@ -194,7 +576,7 @@ msgbuf_init(struct msgbuf *msgbuf)
 	TAILQ_INIT(&msgbuf->bufs);
 }
 
-void
+static void
 msgbuf_drain(struct msgbuf *msgbuf, size_t n)
 {
 	struct ibuf	*buf, *next;
@@ -202,8 +584,8 @@ msgbuf_drain(struct msgbuf *msgbuf, size_t n)
 	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;
+		if (n >= ibuf_size(buf)) {
+			n -= ibuf_size(buf);
 			ibuf_dequeue(msgbuf, buf);
 		} else {
 			buf->rpos += n;
@@ -225,7 +607,7 @@ int
 msgbuf_write(struct msgbuf *msgbuf)
 {
 	struct iovec	 iov[IOV_MAX];
-	struct ibuf	*buf;
+	struct ibuf	*buf, *buf0 = NULL;
 	unsigned int	 i = 0;
 	ssize_t		 n;
 	struct msghdr	 msg;
@@ -241,24 +623,26 @@ msgbuf_write(struct msgbuf *msgbuf)
 	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;
+		if (i > 0 && buf->fd != -1)
+			break;
+		iov[i].iov_base = ibuf_data(buf);
+		iov[i].iov_len = ibuf_size(buf);
 		i++;
 		if (buf->fd != -1)
-			break;
+			buf0 = buf;
 	}
 
 	msg.msg_iov = iov;
 	msg.msg_iovlen = i;
 
-	if (buf != NULL && buf->fd != -1) {
+	if (buf0 != NULL) {
 		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;
+		*(int *)CMSG_DATA(cmsg) = buf0->fd;
 	}
 
 again:
@@ -279,9 +663,9 @@ again:
 	 * 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;
+	if (buf0 != NULL) {
+		close(buf0->fd);
+		buf0->fd = -1;
 	}
 
 	msgbuf_drain(msgbuf, n);
@@ -289,9 +673,17 @@ again:
 	return (1);
 }
 
+uint32_t
+msgbuf_queuelen(struct msgbuf *msgbuf)
+{
+	return (msgbuf->queued);
+}
+
 static void
 ibuf_enqueue(struct msgbuf *msgbuf, struct ibuf *buf)
 {
+	if (buf->max == 0)	/* if buf lives on the stack */
+		abort();	/* abort before causing more harm */
 	TAILQ_INSERT_TAIL(&msgbuf->bufs, buf, entry);
 	msgbuf->queued++;
 }
@@ -300,10 +692,6 @@ static 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);
 }