From: Hans Dedecker Date: Tue, 29 Jan 2019 14:38:36 +0000 (+0100) Subject: dhcpv6-ia: rework append_reply() X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=9d6eadf789a725071f275efe4c5e965ca5e68635;p=project%2Fodhcpd.git dhcpv6-ia: rework append_reply() Signed-off-by: Hans Dedecker --- diff --git a/src/dhcpv6-ia.c b/src/dhcpv6-ia.c index 83de0a2..8ac0a9e 100644 --- a/src/dhcpv6-ia.c +++ b/src/dhcpv6-ia.c @@ -824,197 +824,215 @@ static void valid_until_cb(struct uloop_timeout *event) uloop_timeout_set(event, 1000); } -static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status, +static size_t build_ia(uint8_t *buf, size_t buflen, uint16_t status, const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a, struct interface *iface, bool request) { - if (buflen < sizeof(*ia) + sizeof(struct dhcpv6_ia_prefix)) - return 0; - - struct dhcpv6_ia_hdr out = {ia->type, 0, ia->iaid, 0, 0}; - size_t datalen = sizeof(out); + struct dhcpv6_ia_hdr o_ia = { + .type = ia->type, + .len = 0, + .iaid = ia->iaid, + .t1 = 0, + .t2 = 0, + }; + size_t ia_len = sizeof(o_ia); time_t now = odhcpd_time(); + if (buflen < ia_len) + return 0; + if (status) { struct __attribute__((packed)) { uint16_t type; uint16_t len; - uint16_t value; - } stat = {htons(DHCPV6_OPT_STATUS), htons(sizeof(stat) - 4), - htons(status)}; - - memcpy(buf + datalen, &stat, sizeof(stat)); - datalen += sizeof(stat); - } else { - if (a) { - uint32_t leasetime; - if (a->leasetime) - leasetime = a->leasetime; - else - leasetime = iface->dhcpv4_leasetime; + uint16_t val; + } o_status = { + .type = htons(DHCPV6_OPT_STATUS), + .len = htons(sizeof(o_status) - 4), + .val = htons(status), + }; - uint32_t pref = leasetime; - uint32_t valid = leasetime; + memcpy(buf + ia_len, &o_status, sizeof(o_status)); + ia_len += sizeof(o_status); - struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6; - size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len; - size_t m = get_preferred_addr(addrs, addrlen); + o_ia.len = htons(ia_len - 4); + memcpy(buf, &o_ia, sizeof(o_ia)); - for (size_t i = 0; i < addrlen; ++i) { - uint32_t prefix_pref = addrs[i].preferred; - uint32_t prefix_valid = addrs[i].valid; + return ia_len; + } - if (!valid_addr(&addrs[i], now)) - continue; + if (a) { + uint32_t leasetime; - if (prefix_pref != UINT32_MAX) - prefix_pref -= now; + if (a->leasetime) + leasetime = a->leasetime; + else + leasetime = iface->dhcpv4_leasetime; - if (prefix_valid != UINT32_MAX) - prefix_valid -= now; + uint32_t pref = leasetime; + uint32_t valid = leasetime; - if (a->length < 128) { - struct dhcpv6_ia_prefix p = { - .type = htons(DHCPV6_OPT_IA_PREFIX), - .len = htons(sizeof(p) - 4), - .preferred = htonl(prefix_pref), - .valid = htonl(prefix_valid), - .prefix = (a->managed_size) ? addrs[i].prefix : a->length, - .addr = addrs[i].addr.in6, - }; - p.addr.s6_addr32[1] |= htonl(a->assigned); - p.addr.s6_addr32[2] = p.addr.s6_addr32[3] = 0; + struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6; + size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len; + size_t m = get_preferred_addr(addrs, addrlen); - size_t entrlen = sizeof(p) - 4; + for (size_t i = 0; i < addrlen; ++i) { + uint32_t prefix_pref = addrs[i].preferred; + uint32_t prefix_valid = addrs[i].valid; - if (datalen + entrlen + 4 > buflen || - (a->assigned == 0 && a->managed_size == 0) || - !valid_prefix_length(a, addrs[i].prefix)) - continue; + if (!valid_addr(&addrs[i], now)) + continue; - memcpy(buf + datalen, &p, sizeof(p)); - datalen += entrlen + 4; - } else { - struct dhcpv6_ia_addr n = { - .type = htons(DHCPV6_OPT_IA_ADDR), - .len = htons(sizeof(n) - 4), - .addr = addrs[i].addr.in6, - .preferred = htonl(prefix_pref), - .valid = htonl(prefix_valid) - }; - n.addr.s6_addr32[3] = htonl(a->assigned); - size_t entrlen = sizeof(n) - 4; + if (prefix_pref != UINT32_MAX) + prefix_pref -= now; - if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) || - a->assigned == 0 || - datalen + entrlen + 4 > buflen) - continue; + if (prefix_valid != UINT32_MAX) + prefix_valid -= now; - memcpy(buf + datalen, &n, sizeof(n)); - datalen += entrlen + 4; - } + if (a->length < 128) { + struct dhcpv6_ia_prefix o_ia_p = { + .type = htons(DHCPV6_OPT_IA_PREFIX), + .len = htons(sizeof(o_ia_p) - 4), + .preferred = htonl(prefix_pref), + .valid = htonl(prefix_valid), + .prefix = (a->managed_size) ? addrs[i].prefix : a->length, + .addr = addrs[i].addr.in6, + }; - /* Calculate T1 / T2 based on non-deprecated addresses */ - if (prefix_pref > 0) { - if (prefix_pref < pref) - pref = prefix_pref; + o_ia_p.addr.s6_addr32[1] |= htonl(a->assigned); + o_ia_p.addr.s6_addr32[2] = o_ia_p.addr.s6_addr32[3] = 0; - if (prefix_valid < valid) - valid = prefix_valid; - } - } + if ((a->assigned == 0 && a->managed_size == 0) || + !valid_prefix_length(a, addrs[i].prefix)) + continue; - if (!INFINITE_VALID(a->valid_until)) - /* UINT32_MAX is considered as infinite leasetime */ - a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now; + if (buflen < ia_len + sizeof(o_ia_p)) + return 0; - out.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10); - out.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10); + memcpy(buf + ia_len, &o_ia_p, sizeof(o_ia_p)); + ia_len += sizeof(o_ia_p); + } else { + struct dhcpv6_ia_addr o_ia_a = { + .type = htons(DHCPV6_OPT_IA_ADDR), + .len = htons(sizeof(o_ia_a) - 4), + .addr = addrs[i].addr.in6, + .preferred = htonl(prefix_pref), + .valid = htonl(prefix_valid) + }; + + o_ia_a.addr.s6_addr32[3] = htonl(a->assigned); + + if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) || + a->assigned == 0) + continue; + + if (buflen < ia_len + sizeof(o_ia_a)) + return 0; + + memcpy(buf + ia_len, &o_ia_a, sizeof(o_ia_a)); + ia_len += sizeof(o_ia_a); + } - if (!out.t1) - out.t1 = htonl(1); + /* Calculate T1 / T2 based on non-deprecated addresses */ + if (prefix_pref > 0) { + if (prefix_pref < pref) + pref = prefix_pref; - if (!out.t2) - out.t2 = htonl(1); + if (prefix_valid < valid) + valid = prefix_valid; + } } - if (!request) { - uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4; - uint16_t otype, olen; + if (!INFINITE_VALID(a->valid_until)) + /* UINT32_MAX is considered as infinite leasetime */ + a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now; - dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) { - struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4]; - struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4]; - bool found = false; + o_ia.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10); + o_ia.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10); - if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) && - (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4)) - continue; + if (!o_ia.t1) + o_ia.t1 = htonl(1); - if (a) { - struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6; - size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len; - - for (size_t i = 0; i < addrlen; ++i) { - if (!valid_addr(&addrs[i], now)) - continue; - - struct in6_addr addr = addrs[i].addr.in6; - if (ia->type == htons(DHCPV6_OPT_IA_PD)) { - addr.s6_addr32[1] |= htonl(a->assigned); - addr.s6_addr32[2] = addr.s6_addr32[3] = 0; - - if (!memcmp(&p->addr, &addr, sizeof(addr)) && - p->prefix == ((a->managed) ? addrs[i].prefix : a->length)) - found = true; - } else { - addr.s6_addr32[3] = htonl(a->assigned); - - if (!memcmp(&n->addr, &addr, sizeof(addr))) - found = true; - } - } - } + if (!o_ia.t2) + o_ia.t2 = htonl(1); + } + + if (!request) { + uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4; + uint16_t otype, olen; + + dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) { + struct dhcpv6_ia_prefix *ia_p = (struct dhcpv6_ia_prefix *)&odata[-4]; + struct dhcpv6_ia_addr *ia_a = (struct dhcpv6_ia_addr *)&odata[-4]; + bool found = false; + + if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*ia_p) - 4) && + (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*ia_a) - 4)) + continue; + + if (a) { + struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6; + size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len; + + for (size_t i = 0; i < addrlen; ++i) { + if (!valid_addr(&addrs[i], now)) + continue; + + struct in6_addr addr = addrs[i].addr.in6; + if (ia->type == htons(DHCPV6_OPT_IA_PD)) { + addr.s6_addr32[1] |= htonl(a->assigned); + addr.s6_addr32[2] = addr.s6_addr32[3] = 0; - if (!found) { - if (otype == DHCPV6_OPT_IA_PREFIX) { - struct dhcpv6_ia_prefix inv = { - .type = htons(DHCPV6_OPT_IA_PREFIX), - .len = htons(sizeof(inv) - 4), - .preferred = 0, - .valid = 0, - .prefix = p->prefix, - .addr = p->addr - }; - - if (datalen + sizeof(inv) > buflen) - continue; - - memcpy(buf + datalen, &inv, sizeof(inv)); - datalen += sizeof(inv); + if (!memcmp(&ia_p->addr, &addr, sizeof(addr)) && + ia_p->prefix == ((a->managed) ? addrs[i].prefix : a->length)) + found = true; } else { - struct dhcpv6_ia_addr inv = { - .type = htons(DHCPV6_OPT_IA_ADDR), - .len = htons(sizeof(inv) - 4), - .addr = n->addr, - .preferred = 0, - .valid = 0 - }; - - if (datalen + sizeof(inv) > buflen) - continue; - - memcpy(buf + datalen, &inv, sizeof(inv)); - datalen += sizeof(inv); + addr.s6_addr32[3] = htonl(a->assigned); + + if (!memcmp(&ia_a->addr, &addr, sizeof(addr))) + found = true; } } } + + if (!found) { + if (otype == DHCPV6_OPT_IA_PREFIX) { + struct dhcpv6_ia_prefix o_ia_p = { + .type = htons(DHCPV6_OPT_IA_PREFIX), + .len = htons(sizeof(o_ia_p) - 4), + .preferred = 0, + .valid = 0, + .prefix = ia_p->prefix, + .addr = ia_p->addr, + }; + + if (buflen < ia_len + sizeof(o_ia_p)) + return 0; + + memcpy(buf + ia_len, &o_ia_p, sizeof(o_ia_p)); + ia_len += sizeof(o_ia_p); + } else { + struct dhcpv6_ia_addr o_ia_a = { + .type = htons(DHCPV6_OPT_IA_ADDR), + .len = htons(sizeof(o_ia_a) - 4), + .addr = ia_a->addr, + .preferred = 0, + .valid = 0, + }; + + if (buflen < ia_len + sizeof(o_ia_a)) + continue; + + memcpy(buf + ia_len, &o_ia_a, sizeof(o_ia_a)); + ia_len += sizeof(o_ia_a); + } + } } } - out.len = htons(datalen - 4); - memcpy(buf, &out, sizeof(out)); - return datalen; + o_ia.len = htons(ia_len - 4); + memcpy(buf, &o_ia, sizeof(o_ia)); + return ia_len; } struct log_ctxt { @@ -1330,7 +1348,7 @@ ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface, first = a; } - ia_response_len = append_reply(buf, buflen, status, ia, a, iface, + ia_response_len = build_ia(buf, buflen, status, ia, a, iface, hdr->msg_type == DHCPV6_MSG_REBIND ? false : true); /* Was only a solicitation: mark binding for removal */ @@ -1371,10 +1389,10 @@ ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface, hdr->msg_type == DHCPV6_MSG_DECLINE) { if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) { status = DHCPV6_STATUS_NOBINDING; - ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false); + ia_response_len = build_ia(buf, buflen, status, ia, a, iface, false); } else if (hdr->msg_type == DHCPV6_MSG_RENEW || hdr->msg_type == DHCPV6_MSG_REBIND) { - ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false); + ia_response_len = build_ia(buf, buflen, status, ia, a, iface, false); if (a) { a->flags |= OAF_BOUND; apply_lease(iface, a, true); @@ -1398,7 +1416,7 @@ ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface, } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM && ia_addr_present) { /* Send NOTONLINK for CONFIRM with addr present so that clients restart connection */ status = DHCPV6_STATUS_NOTONLINK; - ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true); + ia_response_len = build_ia(buf, buflen, status, ia, a, iface, true); notonlink = true; }