From 24c064ccbf819f85c8709ea60acb3b278377b408 Mon Sep 17 00:00:00 2001 From: Hans Dedecker Date: Wed, 23 Oct 2013 12:04:01 +0000 Subject: [PATCH] odhcp6c: message retransmission count support The patch implements message retransmission count (MRC) support as described in RFC3315 paragraphs 5.5 and 14 for DHCPv6 request/release/ decline messages. Patch also disables multicast packets loopback. Signed-off-by: Hans Dedecker --- src/dhcpv6.c | 83 ++++++++++++++++++++++++++++----------------------- src/odhcp6c.h | 4 +-- 2 files changed, 48 insertions(+), 39 deletions(-) diff --git a/src/dhcpv6.c b/src/dhcpv6.c index f905a78..08e3225 100644 --- a/src/dhcpv6.c +++ b/src/dhcpv6.c @@ -58,20 +58,20 @@ static int dhcpv6_commit_advert(void); // RFC 3315 - 5.5 Timeout and Delay values static struct dhcpv6_retx dhcpv6_retx[_DHCPV6_MSG_MAX] = { - [DHCPV6_MSG_UNKNOWN] = {false, 1, 120, "", - dhcpv6_handle_reconfigure, NULL}, - [DHCPV6_MSG_SOLICIT] = {true, 1, 120, "SOLICIT", - dhcpv6_handle_advert, dhcpv6_commit_advert}, - [DHCPV6_MSG_REQUEST] = {true, 1, 30, "REQUEST", - dhcpv6_handle_reply, NULL}, - [DHCPV6_MSG_RENEW] = {false, 10, 600, "RENEW", - dhcpv6_handle_reply, NULL}, - [DHCPV6_MSG_REBIND] = {false, 10, 600, "REBIND", - dhcpv6_handle_rebind_reply, NULL}, - [DHCPV6_MSG_RELEASE] = {false, 1, 600, "RELEASE", NULL, NULL}, - [DHCPV6_MSG_DECLINE] = {false, 1, 3, "DECLINE", NULL, NULL}, - [DHCPV6_MSG_INFO_REQ] = {true, 1, 120, "INFOREQ", - dhcpv6_handle_reply, NULL}, + [DHCPV6_MSG_UNKNOWN] = {false, 1, 120, 0, "", + dhcpv6_handle_reconfigure, NULL}, + [DHCPV6_MSG_SOLICIT] = {true, 1, 3600, 0, "SOLICIT", + dhcpv6_handle_advert, dhcpv6_commit_advert}, + [DHCPV6_MSG_REQUEST] = {true, 1, 30, 10, "REQUEST", + dhcpv6_handle_reply, NULL}, + [DHCPV6_MSG_RENEW] = {false, 10, 600, 0, "RENEW", + dhcpv6_handle_reply, NULL}, + [DHCPV6_MSG_REBIND] = {false, 10, 600, 0, "REBIND", + dhcpv6_handle_rebind_reply, NULL}, + [DHCPV6_MSG_RELEASE] = {false, 1, 0, 5, "RELEASE", NULL, NULL}, + [DHCPV6_MSG_DECLINE] = {false, 1, 0, 5, "DECLINE", NULL, NULL}, + [DHCPV6_MSG_INFO_REQ] = {true, 1, 120, 0, "INFOREQ", + dhcpv6_handle_reply, NULL}, }; @@ -157,6 +157,8 @@ int init_dhcpv6(const char *ifname, int request_pd, int sol_timeout) int val = 1; setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val)); setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val)); + val = 0; + setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val, sizeof(val)); setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname)); struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6, @@ -360,7 +362,7 @@ static int64_t dhcpv6_rand_delay(int64_t time) int dhcpv6_request(enum dhcpv6_msg type) { - uint8_t buf[1536]; + uint8_t buf[1536], rc = 0; uint64_t timeout = UINT32_MAX; struct dhcpv6_retx *retx = &dhcpv6_retx[type]; @@ -370,11 +372,7 @@ int dhcpv6_request(enum dhcpv6_msg type) nanosleep(&ts, NULL); } - if (type == DHCPV6_MSG_REQUEST) - timeout = 60; - else if (type == DHCPV6_MSG_RELEASE || type == DHCPV6_MSG_DECLINE) - timeout = 3; - else if (type == DHCPV6_MSG_UNKNOWN) + if (type == DHCPV6_MSG_UNKNOWN) timeout = t1; else if (type == DHCPV6_MSG_RENEW) timeout = (t2 > t1) ? t2 - t1 : 0; @@ -384,7 +382,7 @@ int dhcpv6_request(enum dhcpv6_msg type) if (timeout == 0) return -1; - syslog(LOG_NOTICE, "Sending %s (timeout %us)", retx->name, (unsigned)timeout); + syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)", retx->name, timeout, retx->max_rc); uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed; @@ -396,11 +394,19 @@ int dhcpv6_request(enum dhcpv6_msg type) int64_t rto = 0; do { - rto = (rto == 0) ? (retx->init_timeo * 1000 + - dhcpv6_rand_delay(retx->init_timeo * 1000)) : - (2 * rto + dhcpv6_rand_delay(rto)); + if (rto == 0) { + int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000); - if (rto >= retx->max_timeo * 1000) + // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2) + while (type == DHCPV6_MSG_SOLICIT && delay <= 0) + delay = dhcpv6_rand_delay(retx->init_timeo * 1000); + + rto = (retx->init_timeo * 1000 + delay); + } + else + rto = (2 * rto + dhcpv6_rand_delay(rto)); + + if (retx->max_timeo && (rto >= retx->max_timeo * 1000)) rto = retx->max_timeo * 1000 + dhcpv6_rand_delay(retx->max_timeo * 1000); @@ -413,8 +419,11 @@ int dhcpv6_request(enum dhcpv6_msg type) round_end = timeout * 1000 + start; // Built and send package - if (type != DHCPV6_MSG_UNKNOWN) + if (type != DHCPV6_MSG_UNKNOWN) { + syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)", retx->name, elapsed, rc); dhcpv6_send(type, trid, elapsed / 10); + rc++; + } // Receive rounds for (; len < 0 && round_start < round_end; @@ -442,11 +451,11 @@ int dhcpv6_request(enum dhcpv6_msg type) round_start = odhcp6c_get_milli_time(); elapsed = round_start - start; syslog(LOG_NOTICE, "Got a valid reply after " - "%ums", (unsigned)elapsed); + "%llums", elapsed); if (retx->handler_reply) len = retx->handler_reply( - type, opt, opt_end); + type, rc, opt, opt_end); if (len > 0 && round_end - round_start > 1000) round_end = 1000 + round_start; @@ -456,7 +465,7 @@ int dhcpv6_request(enum dhcpv6_msg type) // Allow if (retx->handler_finish) len = retx->handler_finish(); - } while (len < 0 && elapsed / 1000 < timeout); + } while (len < 0 && ((elapsed / 1000 < timeout) && (!retx->max_rc || rc < retx->max_rc))); return len; } @@ -547,7 +556,7 @@ int dhcpv6_poll_reconfigure(void) } -static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, +static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc, const void *opt, const void *end) { // TODO: should verify the reconfigure message @@ -559,13 +568,13 @@ static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, odata[0] == DHCPV6_MSG_INFO_REQ)) msg = odata[0]; - dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, NULL, NULL); + dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL); return msg; } // Collect all advertised servers -static int dhcpv6_handle_advert(enum dhcpv6_msg orig, +static int dhcpv6_handle_advert(enum dhcpv6_msg orig, _unused const int rc, const void *opt, const void *end) { uint16_t olen, otype; @@ -689,20 +698,20 @@ static int dhcpv6_commit_advert(void) } -static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, +static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc, const void *opt, const void *end) { - dhcpv6_handle_advert(orig, opt, end); + dhcpv6_handle_advert(orig, rc, opt, end); if (dhcpv6_commit_advert() < 0) { - dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, NULL, NULL); + dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL); return -1; } - return dhcpv6_handle_reply(orig, opt, end); + return dhcpv6_handle_reply(orig, rc, opt, end); } -static int dhcpv6_handle_reply(enum dhcpv6_msg orig, +static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc, const void *opt, const void *end) { uint8_t *odata; diff --git a/src/odhcp6c.h b/src/odhcp6c.h index 61dee63..5b9b78f 100644 --- a/src/odhcp6c.h +++ b/src/odhcp6c.h @@ -85,7 +85,7 @@ enum dhcpv6_status { DHCPV6_NoPrefixAvail = 6, }; -typedef int(reply_handler)(enum dhcpv6_msg orig, +typedef int(reply_handler)(enum dhcpv6_msg orig, const int rc, const void *opt, const void *end); // retransmission strategy @@ -93,12 +93,12 @@ struct dhcpv6_retx { bool delay; uint8_t init_timeo; uint16_t max_timeo; + uint8_t max_rc; char name[8]; reply_handler *handler_reply; int(*handler_finish)(void); }; - // DHCPv6 Protocol Headers struct dhcpv6_header { uint8_t msg_type; -- 2.25.1