Attachment 3017 Details for Bug 2735 – re-re-revised diff

[patch] re-re-revised diff

bz2735.diff (text/plain), 3.19 KB, created by Damien Miller on 2017-07-24 15:06:56 AEST

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Creator: Damien Miller

Created: 2017-07-24 15:06:56 AEST

Size: 3.19 KB

patch

obsolete

>diff --git a/openbsd-compat/port-tun.c b/openbsd-compat/port-tun.c
>index a444adf1..40dd8b54 100644
>--- a/openbsd-compat/port-tun.c
>+++ b/openbsd-compat/port-tun.c
>@@ -199,49 +199,51 @@ sys_tun_open(int tun, int mode)
>  */
> 
> #if defined(SSH_TUN_FILTER)
>+/*
>+ * The tunnel forwarding protocol prepends the address family of forwarded
>+ * IP packets using OpenBSD's numbers.
>+ */
> #define OPENBSD_AF_INET		2
> #define OPENBSD_AF_INET6	24
> 
> int
>-sys_tun_infilter(struct Channel *c, char *buf, int len)
>+sys_tun_infilter(struct Channel *c, char *buf, int _len)
> {
>-#if defined(SSH_TUN_PREPEND_AF)
>-	char rbuf[CHAN_RBUF];
>-	struct ip *iph;
>-#endif
>-	u_int32_t *af;
>+	int r;
>+	size_t len;
> 	char *ptr = buf;
>-	int r;
>-
> #if defined(SSH_TUN_PREPEND_AF)
>-	if (len <= 0 || len > (int)(sizeof(rbuf) - sizeof(*af)))
>-		return (-1);
>-	ptr = (char *)&rbuf[0];
>-	bcopy(buf, ptr + sizeof(u_int32_t), len);
>-	len += sizeof(u_int32_t);
>-	af = (u_int32_t *)ptr;
>-
>-	iph = (struct ip *)(ptr + sizeof(u_int32_t));
>-	switch (iph->ip_v) {
>-	case 6:
>-		*af = AF_INET6;
>-		break;
>-	case 4:
>-	default:
>-		*af = AF_INET;
>-		break;
>-	}
>+	char rbuf[CHAN_RBUF];
>+	struct ip iph;
>+#endif
>+#if defined(SSH_TUN_PREPEND_AF) || defined(SSH_TUN_COMPAT_AF)
>+	u_int32_t af;
> #endif
> 
>-#if defined(SSH_TUN_COMPAT_AF)
>-	if (len < (int)sizeof(u_int32_t))
>-		return (-1);
>+	/* XXX update channel input filter API to use unsigned length */
>+	if (_len < 0)
>+		return -1;
>+	len = _len;
> 
>-	af = (u_int32_t *)ptr;
>-	if (*af == htonl(AF_INET6))
>-		*af = htonl(OPENBSD_AF_INET6);
>-	else
>-		*af = htonl(OPENBSD_AF_INET);
>+#if defined(SSH_TUN_PREPEND_AF)
>+	if (len <= sizeof(iph) || len > sizeof(rbuf) - 4)
>+		return -1;
>+	/* Determine address family from packet IP header. */
>+	memcpy(&iph, buf, sizeof(iph));
>+	af = iph.ip_v == 6 ? OPENBSD_AF_INET6 : OPENBSD_AF_INET;
>+	/* Prepend address family to packet using OpenBSD constants */
>+	memcpy(rbuf + 4, buf, len);
>+	len += 4;
>+	POKE_U32(rbuf, htonl(af));
>+	ptr = rbuf;
>+#elif defined(SSH_TUN_COMPAT_AF)
>+	/* Convert existing address family header to OpenBSD value */
>+	if (len <= 4)
>+		return -1;
>+	af = ntohl(PEEK_U32(buf));
>+	/* Put it back */
>+	POKE_U32(buf, htonl(af == AF_INET6 ?
>+	    OPENBSD_AF_INET6 : OPENBSD_AF_INET));
> #endif
> 
> 	if ((r = sshbuf_put_string(&c->input, ptr, len)) != 0)
>@@ -253,7 +255,7 @@ u_char *
> sys_tun_outfilter(struct Channel *c, u_char **data, u_int *dlen)
> {
> 	u_char *buf;
>-	u_int32_t *af;
>+	u_int32_t af;
> 	int r;
> 	size_t xxx_dlen;
> 
>@@ -262,21 +264,19 @@ sys_tun_outfilter(struct Channel *c, u_char **data, u_int *dlen)
> 		fatal("%s: buffer error: %s", __func__, ssh_err(r));
> 	if (dlen != NULL)
> 		*dlen = xxx_dlen;
>-	if (*dlen < sizeof(*af))
>+	if (*dlen < sizeof(af))
> 		return (NULL);
> 	buf = *data;
> 
> #if defined(SSH_TUN_PREPEND_AF)
>-	*dlen -= sizeof(u_int32_t);
>-	buf = *data + sizeof(u_int32_t);
>+	/* skip address family */
>+	*dlen -= sizeof(af);
>+	buf = *data + sizeof(af);
> #elif defined(SSH_TUN_COMPAT_AF)
>-	af = ntohl(*(u_int32_t *)buf);
>-	if (*af == OPENBSD_AF_INET6)
>-		*af = htonl(AF_INET6);
>-	else
>-		*af = htonl(AF_INET);
>+	/* translate address family */
>+	af = (ntohl(PEEK_U32(buf)) == OPENBSD_AF_INET6) ? AF_INET6 : AF_INET;
>+	POKE_U32(buf, htonl(af));
> #endif
>-
> 	return (buf);
> }
> #endif /* SSH_TUN_FILTER */

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Attachments on bug 2735: 3005 | 3006 | 3011 | 3016 | 3017 | 3019 | 3020