X-Git-Url: https://git.decadent.org.uk/gitweb/?a=blobdiff_plain;f=src%2Fdhcpv6.c;h=a36898713435f7ada0142b4201ad76dbc058d309;hb=afe1e5d900c7c1fa66485b70be4691fcf5c58339;hp=0ca86c9b98ce795624cf22edccee00d43687f9ff;hpb=237734ebc82f84d3d0c4c8591390d82f6aff89e3;p=odhcp6c.git diff --git a/src/dhcpv6.c b/src/dhcpv6.c index 0ca86c9..a368987 100644 --- a/src/dhcpv6.c +++ b/src/dhcpv6.c @@ -1,5 +1,5 @@ /** - * Copyright (C) 2012 Steven Barth + * Copyright (C) 2012-2013 Steven Barth * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License v2 as published by @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -135,7 +136,8 @@ int init_dhcpv6(const char *ifname, int request_pd) htons(DHCPV6_OPT_DNS_DOMAIN), htons(DHCPV6_OPT_NTP_SERVER), htons(DHCPV6_OPT_SIP_SERVER_A), - htons(DHCPV6_OPT_SIP_SERVER_D)}; + htons(DHCPV6_OPT_SIP_SERVER_D), + htons(DHCPV6_OPT_PD_EXCLUDE)}; odhcp6c_add_state(STATE_ORO, oro, sizeof(oro)); @@ -188,7 +190,6 @@ static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs) // Build IA_PDs size_t ia_pd_entries, ia_pd_len = 0; - void *ia_pd = NULL; struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries); ia_pd_entries /= sizeof(*e); struct dhcpv6_ia_hdr hdr_ia_pd = { @@ -197,32 +198,51 @@ static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs) 1, 0, 0 }; - struct dhcpv6_ia_prefix pref = { - .type = htons(DHCPV6_OPT_IA_PREFIX), - .len = htons(25), .prefix = request_prefix - }; - - struct dhcpv6_ia_prefix p[ia_pd_entries]; + uint8_t *ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10)); for (size_t i = 0; i < ia_pd_entries; ++i) { - p[i].type = htons(DHCPV6_OPT_IA_PREFIX); - p[i].len = htons(sizeof(p[i]) - 4U); - p[i].preferred = htonl(e[i].preferred); - p[i].valid = htonl(e[i].valid); - p[i].prefix = e[i].length; - p[i].addr = e[i].target; + uint8_t ex_len = 0; + if (e[i].priority > 0) + ex_len = ((e[i].priority - e[i].length - 1) / 8) + 6; + + struct dhcpv6_ia_prefix p = { + .type = htons(DHCPV6_OPT_IA_PREFIX), + .len = htons(sizeof(p) - 4U + ex_len), + .prefix = e[i].length, + .addr = e[i].target + }; + + memcpy(ia_pd + ia_pd_len, &p, sizeof(p)); + ia_pd_len += sizeof(p); + + if (ex_len) { + ia_pd[ia_pd_len++] = 0; + ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE; + ia_pd[ia_pd_len++] = 0; + ia_pd[ia_pd_len++] = ex_len - 4; + ia_pd[ia_pd_len++] = e[i].priority; + + uint32_t excl = ntohl(e[i].router.s6_addr32[1]); + excl >>= (64 - e[i].priority); + excl <<= 8 - ((e[i].priority - e[i].length) % 8); + + for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8) + ia_pd[ia_pd_len + i] = excl & 0xff; + ia_pd_len += ex_len - 5; + } } - ia_pd = p; - ia_pd_len = sizeof(p); - hdr_ia_pd.len = htons(ntohs(hdr_ia_pd.len) + ia_pd_len); - if (request_prefix > 0 && + struct dhcpv6_ia_prefix pref = { + .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)) { - ia_pd = &pref; + ia_pd = (uint8_t*)&pref; ia_pd_len = sizeof(pref); - hdr_ia_pd.len = htons(ntohs(hdr_ia_pd.len) + ia_pd_len); } + hdr_ia_pd.len = htons(ntohs(hdr_ia_pd.len) + ia_pd_len); // Build IA_NAs size_t ia_na_entries, ia_na_len = 0; @@ -241,8 +261,8 @@ static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs) pa[i].type = htons(DHCPV6_OPT_IA_ADDR); pa[i].len = htons(sizeof(pa[i]) - 4U); pa[i].addr = e[i].target; - pa[i].preferred = htonl(e[i].preferred); - pa[i].valid = htonl(e[i].valid); + pa[i].preferred = 0; + pa[i].valid = 0; } ia_na = pa; @@ -520,7 +540,7 @@ static int dhcpv6_handle_advert(_unused enum dhcpv6_msg orig, cand.preference -= 2000; } else if (otype == DHCPV6_OPT_PREF && olen >= 1 && cand.preference >= 0) { - cand.preference = odata[1]; + cand.preference = odata[0]; } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) { cand.wants_reconfigure = true; } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) { @@ -623,7 +643,7 @@ static int dhcpv6_handle_reply(enum dhcpv6_msg orig, if (t3 < 0) t3 = 0; } else { - t1 = t2 = t3 = 86400; + t1 = t2 = t3 = UINT32_MAX; } if (opt) { @@ -647,6 +667,7 @@ static int dhcpv6_handle_reply(enum dhcpv6_msg orig, if (ia_hdr->iaid != 1 || l_t2 < l_t1) continue; + bool error = false; uint16_t stype, slen; uint8_t *sdata; // Test status and bail if error @@ -654,7 +675,10 @@ static int dhcpv6_handle_reply(enum dhcpv6_msg orig, stype, slen, sdata) if (stype == DHCPV6_OPT_STATUS && slen >= 2 && (sdata[0] || sdata[1])) - continue; + error = true; + + if (error) + continue; // Update times if (l_t1 > 0 && t1 > l_t1) @@ -674,6 +698,12 @@ static int dhcpv6_handle_reply(enum dhcpv6_msg orig, if (n < t3) t3 = n; + if (t2 >= t3) + t2 = 8 * t3 / 10; + + if (t1 >= t2) + t1 = 5 * t2 / 8; + } else if (otype == DHCPV6_OPT_DNS_SERVERS) { if (olen % 16 == 0) odhcp6c_add_state(STATE_DNS, odata, olen); @@ -738,7 +768,50 @@ static uint32_t dhcpv6_parse_ia(void *opt, void *end) entry.length = prefix->prefix; entry.target = prefix->addr; - odhcp6c_update_entry(STATE_IA_PD, &entry); + // Parse PD-exclude + bool ok = true; + uint16_t stype, slen; + uint8_t *sdata; + dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U, + odata + olen, stype, slen, sdata) { + if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2) + continue; + + uint8_t elen = sdata[0]; + if (elen > 64) + elen = 64; + + if (elen <= 32 || elen <= entry.length) { + ok = false; + continue; + } + + + uint8_t bytes = ((elen - entry.length - 1) / 8) + 1; + if (slen <= bytes) { + ok = false; + continue; + } + + uint32_t exclude = 0; + do { + exclude = exclude << 8 | sdata[bytes]; + } while (--bytes); + + exclude >>= 8 - ((elen - entry.length) % 8); + exclude <<= 64 - elen; + + // Abusing router & priority fields for exclusion + entry.router = entry.target; + entry.router.s6_addr32[1] |= htonl(exclude); + entry.priority = elen; + } + + if (ok) + odhcp6c_update_entry(STATE_IA_PD, &entry); + + entry.priority = 0; + memset(&entry.router, 0, sizeof(entry.router)); } else if (otype == DHCPV6_OPT_IA_ADDR) { struct dhcpv6_ia_addr *addr = (void*)&odata[-4]; if (olen + 4U < sizeof(*addr))