From b59b64c0be5f16791c77d1b0104f09fd424ac098 Mon Sep 17 00:00:00 2001 Message-Id: In-Reply-To: <600a018ea1136e184b421c86da170b35d05e949f.1578588395.git.lorenzo.bianconi@redhat.com> References: <600a018ea1136e184b421c86da170b35d05e949f.1578588395.git.lorenzo.bianconi@redhat.com> From: Lorenzo Bianconi Date: Tue, 7 Jan 2020 17:50:05 +0100 Subject: [PATCH 2/3] DNSSL: copy dnssl string in order to avoid truncated value ipv6_ra_send can run 2 times in a row before prepare_ipv6_ras updates the dnss list. Copy the dnss dynamic string in packet_put_ra_dnssl_opt in order to avoid sending truncated dnssl list on the wire. Moreover move ip6_hdr definition just before accessing it because the packet can be reallocated if the data area is not big enough for packet content Fixes: 5a12a940f ("Add DNSSL support to OVN") Signed-off-by: Lorenzo Bianconi Signed-off-by: Numan Siddique --- ovn/controller/pinctrl.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/ovn/controller/pinctrl.c b/ovn/controller/pinctrl.c index 04ccb25a8..43b4e9299 100644 --- a/ovn/controller/pinctrl.c +++ b/ovn/controller/pinctrl.c @@ -2417,14 +2417,15 @@ packet_put_ra_rdnss_opt(struct dp_packet *b, uint8_t num, static void packet_put_ra_dnssl_opt(struct dp_packet *b, ovs_be32 lifetime, - char *dnssl_list) + char *dnssl_data) { + char *dnssl_list, *t0, *r0 = NULL, dnssl[255] = {}; size_t prev_l4_size = dp_packet_l4_size(b); size_t size = sizeof(struct ovs_nd_dnssl); - struct ip6_hdr *nh = dp_packet_l3(b); - char *t0, *r0 = NULL, dnssl[255] = {}; int i = 0; + dnssl_list = xstrdup(dnssl_data); + /* Multiple DNS Search List must be 'comma' separated * (e.g. "a.b.c, d.e.f"). Domain names must be encoded * as described in Section 3.1 of RFC1035. @@ -2437,7 +2438,7 @@ packet_put_ra_dnssl_opt(struct dp_packet *b, ovs_be32 lifetime, size += strlen(t0) + 2; if (size > sizeof(dnssl)) { - return; + goto out; } for (t1 = strtok_r(t0, ".", &r1); t1; @@ -2449,6 +2450,8 @@ packet_put_ra_dnssl_opt(struct dp_packet *b, ovs_be32 lifetime, dnssl[i++] = 0; } size = ROUND_UP(size, 8); + + struct ip6_hdr *nh = dp_packet_l3(b); nh->ip6_plen = htons(prev_l4_size + size); struct ovs_nd_dnssl *nd_dnssl = dp_packet_put_uninit(b, sizeof *nd_dnssl); @@ -2464,6 +2467,8 @@ packet_put_ra_dnssl_opt(struct dp_packet *b, ovs_be32 lifetime, uint32_t icmp_csum = packet_csum_pseudoheader6(dp_packet_l3(b)); ra->icmph.icmp6_cksum = csum_finish(csum_continue(icmp_csum, ra, prev_l4_size + size)); +out: + free(dnssl_list); } static void @@ -2571,7 +2576,7 @@ ipv6_ra_send(struct rconn *swconn, struct ipv6_ra_state *ra) } if (ra->config->dnssl.length) { packet_put_ra_dnssl_opt(&packet, htonl(0xffffffff), - ra->config->dnssl.string); + ds_cstr(&ra->config->dnssl)); } if (ra->config->route_info.length) { packet_put_ra_route_info_opt(&packet, htonl(0xffffffff), -- 2.21.1