- From 2f55fec323730a94ed49d401d93b913d85e43b65 Mon Sep 17 00:00:00 2001
- From: Nikos Mavrogiannopoulos <nmav@gnutls.org>
- Date: Mon, 1 Dec 2014 20:10:06 +0100
- Subject: [PATCH 1/2] Re-resolve when reconnecting CSTP and the X-CSTP-DynDNS
- is set by the server
-
- That is, when reconnecting CSTP due to peer tearing the connection
- down attempt to re-resolve its IP. That handles the case where
- the server is using dynamic DNS and is advertising it.
-
- [dwmw2: refactored to simplify it somewhat]
-
- Signed-off-by: Nikos Mavrogiannopoulos <nmav@gnutls.org>
- Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
- ---
- cstp.c | 3 +++
- openconnect-internal.h | 1 +
- ssl.c | 48 +++++++++++++++++++++++++++++++++++++++++++++++-
- 4 files changed, 52 insertions(+), 2 deletions(-)
-
- diff --git a/cstp.c b/cstp.c
- index 3b93538..55225f4 100644
- --- a/cstp.c
- +++ b/cstp.c
- @@ -378,6 +378,9 @@ static int start_cstp_connection(struct openconnect_info *vpninfo)
- int cstpmtu = atol(colon);
- if (cstpmtu > mtu)
- mtu = cstpmtu;
- + } else if (!strcmp(buf + 7, "DynDNS")) {
- + if (!strcmp(colon, "true"))
- + vpninfo->is_dyndns = 1;
- } else if (!strcmp(buf + 7, "Address-IP6")) {
- vpninfo->ip_info.netmask6 = new_option->value;
- } else if (!strcmp(buf + 7, "Address")) {
- diff --git a/openconnect-internal.h b/openconnect-internal.h
- index 1bc79e5..db6c2ba 100644
- --- a/openconnect-internal.h
- +++ b/openconnect-internal.h
- @@ -427,6 +427,7 @@ struct openconnect_info {
- int dtls_local_port;
-
- int deflate;
- + int is_dyndns; /* Attempt to redo DNS lookup on each CSTP reconnect */
- char *useragent;
-
- const char *quit_reason;
- diff --git a/ssl.c b/ssl.c
- index b50652d..d47a819 100644
- --- a/ssl.c
- +++ b/ssl.c
- @@ -106,6 +106,23 @@ unsigned string_is_hostname(const char *str)
- return 1;
- }
-
- +static int match_sockaddr(struct sockaddr *a, struct sockaddr *b)
- +{
- + if (a->sa_family == AF_INET) {
- + struct sockaddr_in *a4 = (void *)a;
- + struct sockaddr_in *b4 = (void *)b;
- +
- + return (a4->sin_addr.s_addr == b4->sin_addr.s_addr) &&
- + (a4->sin_port == b4->sin_port);
- + } else if (a->sa_family == AF_INET6) {
- + struct sockaddr_in6 *a6 = (void *)a;
- + struct sockaddr_in6 *b6 = (void *)b;
- + return !memcmp(&a6->sin6_addr, &b6->sin6_addr, sizeof(a6->sin6_addr) &&
- + a6->sin6_port == b6->sin6_port);
- + } else
- + return 0;
- +}
- +
- int connect_https_socket(struct openconnect_info *vpninfo)
- {
- int ssl_sock = -1;
- @@ -114,7 +131,11 @@ int connect_https_socket(struct openconnect_info *vpninfo)
- if (!vpninfo->port)
- vpninfo->port = 443;
-
- - if (vpninfo->peer_addr) {
- + /* If we're talking to a server which told us it has dynamic DNS, don't
- + just re-use its previous IP address. If we're talking to a proxy, we
- + can use *its* previous IP address. We expect it'll re-do the DNS
- + lookup for the server anyway. */
- + if (vpninfo->peer_addr && (!vpninfo->is_dyndns || vpninfo->proxy)) {
- reconnect:
- #ifdef SOCK_CLOEXEC
- ssl_sock = socket(vpninfo->peer_addr->sa_family, SOCK_STREAM | SOCK_CLOEXEC, IPPROTO_IP);
- @@ -230,6 +251,13 @@ int connect_https_socket(struct openconnect_info *vpninfo)
- if (hints.ai_flags & AI_NUMERICHOST)
- free(hostname);
- ssl_sock = -EINVAL;
- + /* If we were just retrying for dynamic DNS, reconnct using
- + the previously-known IP address */
- + if (vpninfo->peer_addr) {
- + vpn_progress(vpninfo, PRG_ERR,
- + _("Reconnecting to DynDNS server using previously cached IP address\n"));
- + goto reconnect;
- + }
- goto out;
- }
- if (hints.ai_flags & AI_NUMERICHOST)
- @@ -257,6 +285,8 @@ int connect_https_socket(struct openconnect_info *vpninfo)
- if (cancellable_connect(vpninfo, ssl_sock, rp->ai_addr, rp->ai_addrlen) >= 0) {
- /* Store the peer address we actually used, so that DTLS can
- use it again later */
- + free(vpninfo->peer_addr);
- + vpninfo->peer_addrlen = 0;
- vpninfo->peer_addr = malloc(rp->ai_addrlen);
- if (!vpninfo->peer_addr) {
- vpn_progress(vpninfo, PRG_ERR,
- @@ -288,6 +318,17 @@ int connect_https_socket(struct openconnect_info *vpninfo)
- }
- closesocket(ssl_sock);
- ssl_sock = -1;
- +
- + /* If we're in DynDNS mode but this *was* the cached IP address,
- + * don't bother falling back to it if it didn't work. */
- + if (vpninfo->peer_addr && vpninfo->peer_addrlen == rp->ai_addrlen &&
- + match_sockaddr(vpninfo->peer_addr, rp->ai_addr)) {
- + vpn_progress(vpninfo, PRG_TRACE,
- + _("Forgetting non-functional previous peer address\n"));
- + free(vpninfo->peer_addr);
- + vpninfo->peer_addr = 0;
- + vpninfo->peer_addrlen = 0;
- + }
- }
- freeaddrinfo(result);
-
- @@ -296,6 +337,11 @@ int connect_https_socket(struct openconnect_info *vpninfo)
- _("Failed to connect to host %s\n"),
- vpninfo->proxy?:vpninfo->hostname);
- ssl_sock = -EINVAL;
- + if (vpninfo->peer_addr) {
- + vpn_progress(vpninfo, PRG_ERR,
- + _("Reconnecting to DynDNS server using previously cached IP address\n"));
- + goto reconnect;
- + }
- goto out;
- }
- }
- --
- 2.1.3
-
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