From 2dab490cee0d2c175c0eef354b1964d2e147ed64 Mon Sep 17 00:00:00 2001
From: Gregory Nutt <gnutt@nuttx.org>
Date: Fri, 13 Oct 2017 13:31:53 -0600
Subject: [PATCH] 6LoWPAN: Fix a whole in the logic of the previous commit.
It turns out that g_uncomp_hdrlen has other usages so it cannot be modified
as I was doing. Instead, I needed to add a separate localt variable,
protosize, to keep track of the two usages of g_uncomp_hdrlen.
---
net/sixlowpan/sixlowpan_input.c | 103 ++++++++++++++++++++------------
1 file changed, 66 insertions(+), 37 deletions(-)
diff --git a/net/sixlowpan/sixlowpan_input.c b/net/sixlowpan/sixlowpan_input.c
index ed27d34a04..9890c8a547 100644
--- a/net/sixlowpan/sixlowpan_input.c
+++ b/net/sixlowpan/sixlowpan_input.c
@@ -151,10 +151,9 @@ static uint8_t g_bitbucket[UNCOMP_MAXHDR];
****************************************************************************/
static void sixlowpan_uncompress_ipv6hdr(FAR uint8_t *fptr,
- FAR uint8_t *bptr, bool proto)
+ FAR uint8_t *bptr)
{
FAR struct ipv6_hdr_s *ipv6 = (FAR struct ipv6_hdr_s *)bptr;
- uint16_t protosize;
/* Put uncompressed IPv6 header in d_buf. */
@@ -165,54 +164,75 @@ static void sixlowpan_uncompress_ipv6hdr(FAR uint8_t *fptr,
g_frame_hdrlen += IPv6_HDRLEN;
g_uncomp_hdrlen += IPv6_HDRLEN;
+}
- /* Does a protocol header follow the IPv6 header? */
+/****************************************************************************
+ * Name: sixlowpan_uncompress_ipv6proto
+ *
+ * Description:
+ * Copy the protocol header following the IPv4 header
+ *
+ * Input Parameters:
+ * fptr - Pointer to the beginning of the frame under construction
+ * bptr - Output goes here. Normally this is a known offset into d_buf,
+ * may be redirected to g_bitbucket on the case of FRAGN frames.
+ * proto - True: Copy the protocol header following the IPv6 header too.
+ *
+ * Returned Value:
+ * The size of the protocol header that was copied.
+ *
+ ****************************************************************************/
- if (proto)
- {
- /* Yes.. Copy the following protocol header. */
+static uint16_t sixlowpan_uncompress_ipv6proto(FAR uint8_t *fptr,
+ FAR uint8_t *bptr)
+{
+ FAR struct ipv6_hdr_s *ipv6 = (FAR struct ipv6_hdr_s *)bptr;
+ uint16_t protosize = 0;
- switch (ipv6->proto)
- {
+ /* Copy the following protocol header. */
+
+ switch (ipv6->proto)
+ {
#ifdef CONFIG_NET_TCP
- case IP_PROTO_TCP:
- {
- FAR struct tcp_hdr_s *tcp =
- (FAR struct tcp_hdr_s *)(fptr + g_frame_hdrlen);
+ case IP_PROTO_TCP:
+ {
+ FAR struct tcp_hdr_s *tcp =
+ (FAR struct tcp_hdr_s *)(fptr + g_frame_hdrlen);
- /* The TCP header length is encoded in the top 4 bits of the
- * tcpoffset field (in units of 32-bit words).
- */
+ /* The TCP header length is encoded in the top 4 bits of the
+ * tcpoffset field (in units of 32-bit words).
+ */
- protosize = ((uint16_t)tcp->tcpoffset >> 4) << 2;
- }
- break;
+ protosize = ((uint16_t)tcp->tcpoffset >> 4) << 2;
+ }
+ break;
#endif
#ifdef CONFIG_NET_UDP
- case IP_PROTO_UDP:
- protosize = sizeof(struct udp_hdr_s);
- break;
+ case IP_PROTO_UDP:
+ protosize = sizeof(struct udp_hdr_s);
+ break;
#endif
#ifdef CONFIG_NET_ICMPv6
- case IP_PROTO_ICMP6:
- protosize = sizeof(struct icmpv6_hdr_s);
- break;
+ case IP_PROTO_ICMP6:
+ protosize = sizeof(struct icmpv6_hdr_s);
+ break;
#endif
- default:
- nwarn("WARNING: Unrecognized proto: %u\n", ipv6->proto);
- return;
- }
+ default:
+ nwarn("WARNING: Unrecognized proto: %u\n", ipv6->proto);
+ return 0;
+ }
- /* Copy the protocol header. */
+ /* Copy the protocol header. */
- memcpy((FAR uint8_t *)ipv6 + g_uncomp_hdrlen, fptr + g_frame_hdrlen,
- protosize);
+ memcpy((FAR uint8_t *)ipv6 + g_uncomp_hdrlen, fptr + g_frame_hdrlen,
+ protosize);
- g_frame_hdrlen += protosize;
- }
+ g_frame_hdrlen += protosize;
+ g_uncomp_hdrlen += protosize;
+ return protosize;
}
/****************************************************************************
@@ -266,6 +286,7 @@ static int sixlowpan_frame_process(FAR struct radio_driver_s *radio,
uint16_t paysize; /* Size of the data payload */
uint16_t fragtag = 0; /* Tag of the fragment */
uint8_t fragoffset = 0; /* Offset of the fragment in the IP packet */
+ uint8_t protosize = 0; /* Length of the protocal header (treated like payload) */
bool isfrag = false; /* true: Frame is a fragment */
bool isfrag1 = false; /* true: Frame is the first fragement of the series */
int reqsize; /* Required buffer size */
@@ -447,11 +468,19 @@ static int sixlowpan_frame_process(FAR struct radio_driver_s *radio,
{
ninfo("IPv6 Dispatch\n");
- /* NOTE: A protocol header will follow only on a non-fragmented
- * packet or on the first fragment of a fragmented packet.
+ /* Uncompress the IPv6 header */
+
+ sixlowpan_uncompress_ipv6hdr(fptr, bptr);
+
+ /* A protocol header will follow the IPv6 header only on a non-
+ * fragmented packet or on the first fragment of a fragmented
+ * packet.
*/
- sixlowpan_uncompress_ipv6hdr(fptr, bptr, !isfrag || isfrag1);
+ if (!isfrag || isfrag1)
+ {
+ protosize = sixlowpan_uncompress_ipv6proto(fptr, bptr);
+ }
}
else
{
@@ -470,7 +499,7 @@ static int sixlowpan_frame_process(FAR struct radio_driver_s *radio,
* begin placing the data payload.
*/
- reass->rb_boffset = g_uncomp_hdrlen;
+ reass->rb_boffset = g_uncomp_hdrlen - protosize;
}
/* No.. is this a subsequent fragment in the same sequence? */
--
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