laforge has submitted this change. (
https://gerrit.osmocom.org/c/osmo-iuh/+/34963?usp=email )
Change subject: ranap_transp_layer_addr_decode2(): Fix decoding X.213 IPv4
address len=7
......................................................................
ranap_transp_layer_addr_decode2(): Fix decoding X.213 IPv4 address len=7
It was found in the field that some peers sends an X.213 IP address
consisting of 7 bytes (1byte IDP/AFI, 2byte ICP, 4 byte IPv4 address) insetad
of 20 bytes.
This is indeed possible when reading ITU Rec X.213 A.5.2.3, where it
states that Table A5 defining the 17 bytes DSP len for IANA ICP
"gives the maximum length of the DSP". So smaller values are still
possible/acceptable.
Related: SYS#6623
Change-Id: I507fb1605d976bd8573162e4fa81721245330184
---
M src/iu_helpers.c
1 file changed, 30 insertions(+), 4 deletions(-)
Approvals:
laforge: Looks good to me, approved
Jenkins Builder: Verified
neels: Looks good to me, but someone else must approve
diff --git a/src/iu_helpers.c b/src/iu_helpers.c
index 718c30a..5c7ff31 100644
--- a/src/iu_helpers.c
+++ b/src/iu_helpers.c
@@ -140,14 +140,21 @@
memset(addr, 0, sizeof(*addr));
- if (len == 20 && buf[0] == 0x35) {
- /* For an X.213 NSAP encoded address we expect a buffer of
exactly 20 bytes (3 bytes IDP + 17 bytes
- * DSP). we also expect AFI = 0x35, which means that two byte
IDI and an IP address follows. (see also
- * comments in function ranap_new_transp_layer_addr below) */
+ if ((len == 7 || len == 20) && buf[0] == 0x35) {
+ /* ITU-T Rec. X.213 A.5.2.1.2.7, RFC 1888 section 6
+ * For an X.213 NSAP encoded address we expect:
+ * 3 bytes IDP (first byte AFI = 0x35, which means that two
byte IDI and an IP address follows)
+ * Either 4 or 17 bytes of DSP containing the IP address.
+ * (see also comments in function ranap_new_transp_layer_addr
below) */
x213_nsap = true;
icp = osmo_load16be(&buf[1]);
switch (icp) {
case 0x0000:
+ /* "RFC 1888 provides guidance on how to embed an IPv6
address within the DSP of an NSAP
+ * address. The IPv6 address is carried in the first
16 octets of the DSP.
+ * Octet 17 of the DSP is set to zero, but has no
significance for IPv6." */
+ if (len != 20)
+ return -EINVAL;
addr->u.sa.sa_family = AF_INET6;
memcpy(addr->u.sin6.sin6_addr.s6_addr, buf + 3,
sizeof(addr->u.sin6.sin6_addr.s6_addr));
break;
--
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Gerrit-Project: osmo-iuh
Gerrit-Branch: master
Gerrit-Change-Id: I507fb1605d976bd8573162e4fa81721245330184
Gerrit-Change-Number: 34963
Gerrit-PatchSet: 3
Gerrit-Owner: pespin <pes...@sysmocom.de>
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: laforge <lafo...@osmocom.org>
Gerrit-Reviewer: neels <nhofm...@sysmocom.de>
Gerrit-MessageType: merged
