From 0523bdd981f0cc56c2391f73649baeda39ab43e0 Mon Sep 17 00:00:00 2001 From: Hans Dedecker Date: Thu, 11 Apr 2019 22:48:28 +0200 Subject: router: improve code readibility No functional changes; just improve code readibilty in send_router_advert() Signed-off-by: Hans Dedecker --- src/router.c | 252 ++++++++++++++++++++++++++++++++--------------------------- 1 file changed, 137 insertions(+), 115 deletions(-) diff --git a/src/router.c b/src/router.c index 827e3e8..93b75bf 100644 --- a/src/router.c +++ b/src/router.c @@ -284,12 +284,12 @@ static bool router_icmpv6_valid(struct sockaddr_in6 *source, uint8_t *data, size /* Detect whether a default route exists, also find the source prefixes */ static bool parse_routes(struct odhcpd_ipaddr *n, ssize_t len) { - rewind(fp_route); - - char line[512], ifname[16]; - bool found_default = false; struct odhcpd_ipaddr p = { .addr.in6 = IN6ADDR_ANY_INIT, .prefix = 0, .dprefix = 0, .preferred = 0, .valid = 0}; + bool found_default = false; + char line[512], ifname[16]; + + rewind(fp_route); while (fgets(line, sizeof(line), fp_route)) { uint32_t rflags; @@ -366,39 +366,71 @@ enum { IOV_RA_PFXS, IOV_RA_ROUTES, IOV_RA_DNS, - IOV_RA_DNS_ADDR, IOV_RA_SEARCH, IOV_RA_ADV_INTERVAL, IOV_RA_TOTAL, }; +struct adv_msg { + struct nd_router_advert h; + struct icmpv6_opt lladdr; + struct nd_opt_mtu mtu; +}; + +struct nd_opt_dns_server { + uint8_t type; + uint8_t len; + uint8_t pad; + uint8_t pad2; + uint32_t lifetime; + struct in6_addr addr[]; +}; + +struct nd_opt_search_list { + uint8_t type; + uint8_t len; + uint8_t pad; + uint8_t pad2; + uint32_t lifetime; + uint8_t name[]; +}; + +struct nd_opt_route_info { + uint8_t type; + uint8_t len; + uint8_t prefix; + uint8_t flags; + uint32_t lifetime; + uint32_t addr[4]; +}; + /* Router Advert server mode */ -static uint64_t send_router_advert(struct interface *iface, const struct in6_addr *from) +static int send_router_advert(struct interface *iface, const struct in6_addr *from) { time_t now = odhcpd_time(); - int mtu = iface->ra_mtu; - int hlim = iface->ra_hoplimit; + struct odhcpd_ipaddr *addrs = NULL; + struct adv_msg adv; + struct nd_opt_prefix_info *pfxs = NULL; + struct nd_opt_dns_server *dns = NULL; + struct nd_opt_search_list *search = NULL; + struct nd_opt_route_info *routes = NULL; + struct nd_opt_adv_interval adv_interval; + struct iovec iov[IOV_RA_TOTAL]; + struct sockaddr_in6 dest; + size_t dns_sz = 0, search_sz = 0, pfxs_cnt = 0, routes_cnt = 0; + ssize_t addr_cnt = 0; + uint32_t minvalid = UINT32_MAX, maxival; + int msecs, mtu = iface->ra_mtu, hlim = iface->ra_hoplimit; + bool default_route = false; + bool valid_prefix = false; char buf[INET6_ADDRSTRLEN]; - if (mtu == 0) - mtu = odhcpd_get_interface_config(iface->ifname, "mtu"); - - if (mtu < 1280) - mtu = 1280; + memset(&adv, 0, sizeof(adv)); + adv.h.nd_ra_type = ND_ROUTER_ADVERT; if (hlim == 0) hlim = odhcpd_get_interface_config(iface->ifname, "hop_limit"); - struct { - struct nd_router_advert h; - struct icmpv6_opt lladdr; - struct nd_opt_mtu mtu; - } adv = { - .h = {{.icmp6_type = ND_ROUTER_ADVERT, .icmp6_code = 0}, 0, 0}, - .lladdr = {ND_OPT_SOURCE_LINKADDR, 1, {0}}, - .mtu = {ND_OPT_MTU, 1, 0, htonl(mtu)}, - }; - if (hlim > 0) adv.h.nd_ra_curhoplimit = hlim; @@ -417,22 +449,32 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add adv.h.nd_ra_reachable = htonl(iface->ra_reachabletime); adv.h.nd_ra_retransmit = htonl(iface->ra_retranstime); + adv.lladdr.type = ND_OPT_SOURCE_LINKADDR; + adv.lladdr.len = 1; odhcpd_get_mac(iface, adv.lladdr.data); - /* If not currently shutting down */ - struct odhcpd_ipaddr *addrs = NULL; - ssize_t ipcnt = 0; - uint32_t minvalid = UINT32_MAX; - bool default_route = false; - bool valid_prefix = false; + adv.mtu.nd_opt_mtu_type = ND_OPT_MTU; + adv.mtu.nd_opt_mtu_len = 1; + + if (mtu == 0) + mtu = odhcpd_get_interface_config(iface->ifname, "mtu"); + + if (mtu < 1280) + mtu = 1280; + + adv.mtu.nd_opt_mtu_mtu = htonl(mtu); + + iov[IOV_RA_ADV].iov_base = (char *)&adv; + iov[IOV_RA_ADV].iov_len = sizeof(adv); /* If not shutdown */ if (iface->timer_rs.cb) { size_t size = sizeof(*addrs) * iface->addr6_len; + addrs = alloca(size); memcpy(addrs, iface->addr6, size); - ipcnt = iface->addr6_len; + addr_cnt = iface->addr6_len; /* Check default route */ if (iface->default_router) { @@ -440,30 +482,14 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add if (iface->default_router > 1) valid_prefix = true; - } else if (parse_routes(addrs, ipcnt)) + } else if (parse_routes(addrs, addr_cnt)) default_route = true; } - /* DNS Recursive DNS */ - struct in6_addr dns_pref, *dns_addr = NULL; - size_t dns_cnt = 0; - - if (iface->ra_dns) { - if (iface->dns_cnt > 0) { - dns_addr = iface->dns; - dns_cnt = iface->dns_cnt; - } else if (!odhcpd_get_interface_dns_addr(iface, &dns_pref)) { - dns_addr = &dns_pref; - dns_cnt = 1; - } - } - /* Construct Prefix Information options */ - size_t pfxs_cnt = 0; - struct nd_opt_prefix_info *pfxs = NULL; - - for (ssize_t i = 0; i < ipcnt; ++i) { + for (ssize_t i = 0; i < addr_cnt; ++i) { struct odhcpd_ipaddr *addr = &addrs[i]; + struct nd_opt_prefix_info *p = NULL; uint32_t preferred = 0; uint32_t valid = 0; @@ -483,7 +509,6 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add continue; /* PIO filtered out of this RA */ } - struct nd_opt_prefix_info *p = NULL; for (size_t i = 0; i < pfxs_cnt; ++i) { if (addr->prefix == pfxs[i].nd_opt_pi_prefix_len && !odhcpd_bmemcmp(&pfxs[i].nd_opt_pi_prefix, @@ -539,9 +564,11 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add p->nd_opt_pi_valid_time = htonl(valid); } + iov[IOV_RA_PFXS].iov_base = (char *)pfxs; + iov[IOV_RA_PFXS].iov_len = pfxs_cnt * sizeof(*pfxs); + /* Calculate periodic transmit */ - uint32_t maxival; - int msecs = calc_adv_interval(iface, minvalid, &maxival); + msecs = calc_adv_interval(iface, minvalid, &maxival); if (default_route) { if (!valid_prefix) { @@ -556,22 +583,33 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add syslog(LOG_INFO, "Using a RA lifetime of %d seconds on %s", ntohs(adv.h.nd_ra_router_lifetime), iface->name); - struct { - uint8_t type; - uint8_t len; - uint8_t pad; - uint8_t pad2; - uint32_t lifetime; - } dns = {ND_OPT_RECURSIVE_DNS, (1 + (2 * dns_cnt)), 0, 0, 0}; + /* DNS options */ + if (iface->ra_dns) { + struct in6_addr dns_pref, *dns_addr = NULL; + size_t dns_cnt = 0, search_padded = 0, search_len = iface->search_len; + uint8_t *search_domain = iface->search; + + /* DNS Recursive DNS */ + if (iface->dns_cnt > 0) { + dns_addr = iface->dns; + dns_cnt = iface->dns_cnt; + } else if (!odhcpd_get_interface_dns_addr(iface, &dns_pref)) { + dns_addr = &dns_pref; + dns_cnt = 1; + } - /* DNS Search options */ - uint8_t *search_domain = NULL; - size_t search_len = 0, search_padded = 0; + if (dns_cnt) { + dns_sz = sizeof(*dns) + sizeof(struct in6_addr)*dns_cnt; - if (iface->ra_dns) { - search_len = iface->search_len; - search_domain = iface->search; + dns = alloca(dns_sz); + memset(dns, 0, dns_sz); + dns->type = ND_OPT_RECURSIVE_DNS; + dns->len = 1 + (2 * dns_cnt); + dns->lifetime = htonl(maxival*10); + memcpy(dns->addr, dns_addr, sizeof(struct in6_addr)*dns_cnt); + } + /* DNS Search options */ if (!search_domain && !res_init() && _res.dnsrch[0] && _res.dnsrch[0][0]) { uint8_t search_buf[256]; @@ -582,42 +620,33 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add search_len = len; } } - } - if (search_len > 0) - search_padded = ((search_len + 7) & (~7)) + 8; - - struct { - uint8_t type; - uint8_t len; - uint8_t pad; - uint8_t pad2; - uint32_t lifetime; - uint8_t name[]; - } *search = alloca(sizeof(*search) + search_padded); - - search->type = ND_OPT_DNS_SEARCH; - search->len = search_len ? ((sizeof(*search) + search_padded) / 8) : 0; - search->pad = 0; - search->pad2 = 0; - - if (search_len > 0) { - memcpy(search->name, search_domain, search_len); - memset(&search->name[search_len], 0, search_padded - search_len); + if (search_len > 0) + search_padded = ((search_len + 7) & (~7)) + 8; + + search_sz = sizeof(*search) + search_padded; + + search = alloca(search_sz); + memset(search, 0, search_sz); + search->type = ND_OPT_DNS_SEARCH; + search->len = search_len ? ((sizeof(*search) + search_padded) / 8) : 0; + search->lifetime = htonl(maxival*10); + + if (search_len > 0) { + memcpy(search->name, search_domain, search_len); + memset(&search->name[search_len], 0, search_padded - search_len); + } } - size_t routes_cnt = 0; - struct { - uint8_t type; - uint8_t len; - uint8_t prefix; - uint8_t flags; - uint32_t lifetime; - uint32_t addr[4]; - } *tmp, *routes = NULL; - - for (ssize_t i = 0; i < ipcnt; ++i) { + iov[IOV_RA_DNS].iov_base = (char *)dns; + iov[IOV_RA_DNS].iov_len = dns_sz; + iov[IOV_RA_SEARCH].iov_base = (char *)search; + iov[IOV_RA_SEARCH].iov_len = search_sz; + + for (ssize_t i = 0; i < addr_cnt; ++i) { struct odhcpd_ipaddr *addr = &addrs[i]; + struct nd_opt_route_info *tmp; + if (addr->dprefix > 64 || addr->dprefix == 0 || addr->valid <= (uint32_t)now) { syslog(LOG_INFO, "Address %s (dprefix %d, valid %u) not suitable as RA route on %s", inet_ntop(AF_INET6, &addr->addr.in6, buf, sizeof(buf)), @@ -659,6 +688,7 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add routes[routes_cnt].flags |= ND_RA_PREF_LOW; else if (iface->route_preference > 0) routes[routes_cnt].flags |= ND_RA_PREF_HIGH; + routes[routes_cnt].lifetime = htonl(TIME_LEFT(addr->valid, now)); routes[routes_cnt].addr[0] = addr->addr.in6.s6_addr32[0]; routes[routes_cnt].addr[1] = addr->addr.in6.s6_addr32[1]; @@ -668,24 +698,16 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add ++routes_cnt; } - search->lifetime = htonl(maxival*10); - dns.lifetime = search->lifetime; - - struct icmpv6_opt adv_interval = { - .type = ND_OPT_RTR_ADV_INTERVAL, - .len = 1, - .data = {0, 0, (maxival*1000) >> 24, (maxival*1000) >> 16, (maxival*1000) >> 8, maxival*1000} - }; - - struct iovec iov[IOV_RA_TOTAL] = { - [IOV_RA_ADV] = {&adv, sizeof(adv)}, - [IOV_RA_PFXS] = {pfxs, pfxs_cnt * sizeof(*pfxs)}, - [IOV_RA_ROUTES] = {routes, routes_cnt * sizeof(*routes)}, - [IOV_RA_DNS] = {&dns, (dns_cnt) ? sizeof(dns) : 0}, - [IOV_RA_DNS_ADDR] = {dns_addr, dns_cnt * sizeof(*dns_addr)}, - [IOV_RA_SEARCH] = {search, search->len * 8}, - [IOV_RA_ADV_INTERVAL] = {&adv_interval, adv_interval.len * 8}}; - struct sockaddr_in6 dest; + iov[IOV_RA_ROUTES].iov_base = (char *)routes; + iov[IOV_RA_ROUTES].iov_len = routes_cnt * sizeof(*routes); + + memset(&adv_interval, 0, sizeof(adv_interval)); + adv_interval.nd_opt_adv_interval_type = ND_OPT_RTR_ADV_INTERVAL; + adv_interval.nd_opt_adv_interval_len = 1; + adv_interval.nd_opt_adv_interval_ival = htonl(maxival); + + iov[IOV_RA_ADV_INTERVAL].iov_base = (char *)&adv_interval; + iov[IOV_RA_ADV_INTERVAL].iov_len = adv_interval.nd_opt_adv_interval_len * 8; memset(&dest, 0, sizeof(dest)); dest.sin6_family = AF_INET6; -- cgit v1.2.3