From d2c90000292f62962276579fa6b2eac1ff4b76e6 Mon Sep 17 00:00:00 2001 From: Steven Barth Date: Mon, 7 Oct 2013 10:21:34 +0200 Subject: [PATCH] odhcp6c: improve server selection --- src/dhcpv6.c | 55 ++++++++++++++++++++++++++++++--------------------- src/odhcp6c.c | 23 +++++++++++++++------ src/odhcp6c.h | 2 +- 3 files changed, 50 insertions(+), 30 deletions(-) diff --git a/src/dhcpv6.c b/src/dhcpv6.c index f128ed8..0285923 100644 --- a/src/dhcpv6.c +++ b/src/dhcpv6.c @@ -82,7 +82,7 @@ static int64_t t1 = 0, t2 = 0, t3 = 0; // IA states static int request_prefix = -1; -static enum odhcp6c_ia_mode na_mode = IA_MODE_NONE; +static enum odhcp6c_ia_mode na_mode = IA_MODE_NONE, pd_mode = IA_MODE_NONE; static bool accept_reconfig = false; // Reconfigure key @@ -167,9 +167,10 @@ int init_dhcpv6(const char *ifname, int request_pd) } -void dhcpv6_set_ia_na_mode(enum odhcp6c_ia_mode mode) +void dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd) { - na_mode = mode; + na_mode = na; + pd_mode = pd; } @@ -247,9 +248,7 @@ static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs) .type = htons(DHCPV6_OPT_IA_PREFIX), .len = htons(25), .prefix = request_prefix }; - if (request_prefix > 0 && ia_pd_len == 0 && - (type == DHCPV6_MSG_SOLICIT || - type == DHCPV6_MSG_REQUEST)) { + if (request_prefix > 0 && ia_pd_len == 0 && type == DHCPV6_MSG_SOLICIT) { ia_pd = (uint8_t*)&pref; ia_pd_len = sizeof(pref); } @@ -331,7 +330,7 @@ static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs) } // Disable IAs if not used - if (type != DHCPV6_MSG_REQUEST && type != DHCPV6_MSG_SOLICIT) { + if (type != DHCPV6_MSG_SOLICIT) { iov[5].iov_len = 0; if (ia_na_len == 0) iov[7].iov_len = 0; @@ -446,7 +445,7 @@ int dhcpv6_request(enum dhcpv6_msg type) len = retx->handler_reply( type, opt, opt_end); - if (round_end - round_start > 1000) + if (len > 0 && round_end - round_start > 1000) round_end = 1000 + round_start; } } @@ -569,6 +568,7 @@ static int dhcpv6_handle_advert(enum dhcpv6_msg orig, uint16_t olen, otype; uint8_t *odata; struct dhcpv6_server_cand cand = {false, false, 0, 0, {0}, NULL, NULL, 0, 0}; + bool have_na = false, have_pd = false; dhcpv6_for_each_option(opt, end, otype, olen, odata) { if (orig == DHCPV6_MSG_SOLICIT && @@ -581,14 +581,6 @@ static int dhcpv6_handle_advert(enum dhcpv6_msg orig, if (otype == DHCPV6_OPT_SERVERID && olen <= 130) { memcpy(cand.duid, odata, olen); cand.duid_len = olen; - } else if (otype == DHCPV6_OPT_STATUS && olen >= 2 && !odata[0] - && odata[1] == DHCPV6_NoAddrsAvail) { - if (na_mode == IA_MODE_FORCE) { - return -1; - } else { - cand.has_noaddravail = true; - cand.preference -= 1000; - } } else if (otype == DHCPV6_OPT_STATUS && olen >= 2 && !odata[0] && odata[1] == DHCPV6_NoPrefixAvail) { cand.preference -= 2000; @@ -600,17 +592,34 @@ static int dhcpv6_handle_advert(enum dhcpv6_msg orig, } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) { struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4]; uint8_t *oend = odata + olen, *d; - dhcpv6_for_each_option(&h[1], oend, otype, olen, d) { + dhcpv6_for_each_option(&h[1], oend, otype, olen, d) if (otype == DHCPV6_OPT_IA_PREFIX) - cand.preference += 2000; - else if (otype == DHCPV6_OPT_STATUS && - olen >= 2 && d[0] == 0 && - d[1] == DHCPV6_NoPrefixAvail) - cand.preference -= 2000; - } + have_pd = true; + } else if (otype == DHCPV6_OPT_IA_NA) { + struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4]; + uint8_t *oend = odata + olen, *d; + dhcpv6_for_each_option(&h[1], oend, otype, olen, d) + if (otype == DHCPV6_OPT_IA_ADDR) + have_na = true; } } + if ((!have_na && na_mode == IA_MODE_FORCE) || + (!have_pd && pd_mode == IA_MODE_FORCE)) + return -1; + + if (na_mode != IA_MODE_NONE && !have_na) { + cand.has_noaddravail = true; + cand.preference -= 1000; + } + + if (pd_mode != IA_MODE_NONE) { + if (have_pd) + cand.preference += 2000; + else + cand.preference -= 2000; + } + if (cand.duid_len > 0) { cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len); cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len); diff --git a/src/odhcp6c.c b/src/odhcp6c.c index d35da2e..7e0710b 100644 --- a/src/odhcp6c.c +++ b/src/odhcp6c.c @@ -56,26 +56,29 @@ int main(_unused int argc, char* const argv[]) char *optpos; uint16_t opttype; enum odhcp6c_ia_mode ia_na_mode = IA_MODE_TRY; + enum odhcp6c_ia_mode ia_pd_mode = IA_MODE_TRY; static struct in6_addr ifid = IN6ADDR_ANY_INIT; bool help = false, daemonize = false; int logopt = LOG_PID; int c, request_pd = 0; - while ((c = getopt(argc, argv, "S::N:P:c:i:r:s:khedp:")) != -1) { + while ((c = getopt(argc, argv, "S::N:P:Fc:i:r:s:khedp:")) != -1) { switch (c) { case 'S': allow_slaac_only = (optarg) ? atoi(optarg) : -1; break; case 'N': - if (!strcmp(optarg, "force")) + if (!strcmp(optarg, "force")) { ia_na_mode = IA_MODE_FORCE; - else if (!strcmp(optarg, "none")) + allow_slaac_only = -1; + } else if (!strcmp(optarg, "none")) { ia_na_mode = IA_MODE_NONE; - else if (!strcmp(optarg, "try")) + } else if (!strcmp(optarg, "try")) { ia_na_mode = IA_MODE_TRY; - else + } else{ help = true; + } break; case 'P': @@ -85,6 +88,13 @@ int main(_unused int argc, char* const argv[]) request_pd = strtoul(optarg, NULL, 10); if (request_pd == 0) request_pd = -1; + + ia_pd_mode = IA_MODE_TRY; + break; + + case 'F': + allow_slaac_only = -1; + ia_pd_mode = IA_MODE_FORCE; break; case 'c': @@ -198,7 +208,7 @@ int main(_unused int argc, char* const argv[]) odhcp6c_clear_state(STATE_SNTP_FQDN); odhcp6c_clear_state(STATE_SIP_IP); odhcp6c_clear_state(STATE_SIP_FQDN); - dhcpv6_set_ia_na_mode(ia_na_mode); + dhcpv6_set_ia_mode(ia_na_mode, ia_pd_mode); bound = false; // Server candidates need deep-delete @@ -329,6 +339,7 @@ static int usage(void) " -S