From 348cbc2efee1281c3b39e705114f44eca72a8247 Mon Sep 17 00:00:00 2001 From: Hans Dedecker Date: Wed, 13 Nov 2013 16:04:42 +0100 Subject: [PATCH] Server unicast option support --- src/dhcpv6.c | 49 +++++++++++++++++++++++++++++++++++--- src/odhcp6c.c | 65 +++++++++++++++++++++++++++++++++++++++++++++++++-- src/odhcp6c.h | 3 +++ 3 files changed, 112 insertions(+), 5 deletions(-) diff --git a/src/dhcpv6.c b/src/dhcpv6.c index 9b03227..b727818 100644 --- a/src/dhcpv6.c +++ b/src/dhcpv6.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include @@ -95,6 +96,8 @@ static int64_t t1 = 0, t2 = 0, t3 = 0; static int request_prefix = -1; static enum odhcp6c_ia_mode na_mode = IA_MODE_NONE, pd_mode = IA_MODE_NONE; static bool accept_reconfig = false; +// Server unicast address +static struct in6_addr server_addr = IN6ADDR_ANY_INIT; // Reconfigure key static uint8_t reconf_key[16]; @@ -156,6 +159,7 @@ int init_dhcpv6(const char *ifname, int request_pd, int sol_timeout) htons(DHCPV6_OPT_SIP_SERVER_A), htons(DHCPV6_OPT_DNS_SERVERS), htons(DHCPV6_OPT_DNS_DOMAIN), + htons(DHCPV6_OPT_UNICAST), htons(DHCPV6_OPT_NTP_SERVER), htons(DHCPV6_OPT_AFTR_NAME), htons(DHCPV6_OPT_PD_EXCLUDE), @@ -371,7 +375,29 @@ static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs) 0, ALL_DHCPV6_RELAYS, ifindex}; struct msghdr msg = {&srv, sizeof(srv), iov, cnt, NULL, 0, 0}; - sendmsg(sock, &msg, 0); + switch (type) { + case DHCPV6_MSG_REQUEST: + case DHCPV6_MSG_RENEW: + case DHCPV6_MSG_RELEASE: + case DHCPV6_MSG_DECLINE: + if (!IN6_IS_ADDR_UNSPECIFIED(&server_addr) && + odhcp6c_addr_in_scope(&server_addr)) { + srv.sin6_addr = server_addr; + if (!IN6_IS_ADDR_LINKLOCAL(&server_addr)) + srv.sin6_scope_id = 0; + } + break; + default: + break; + } + + if (sendmsg(sock, &msg, 0) < 0) { + char in6_str[INET6_ADDRSTRLEN]; + + syslog(LOG_ERR, "Failed to send DHCPV6 message to %s (%s)", + inet_ntop(AF_INET6, (const void *)&srv.sin6_addr, + in6_str, sizeof(in6_str)), strerror(errno)); + } } @@ -653,7 +679,8 @@ static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc, { uint16_t olen, otype; uint8_t *odata, pref = 0; - struct dhcpv6_server_cand cand = {false, false, 0, 0, {0}, NULL, NULL, 0, 0}; + struct dhcpv6_server_cand cand = {false, false, 0, 0, {0}, + IN6ADDR_ANY_INIT, NULL, NULL, 0, 0}; bool have_na = false; int have_pd = 0; @@ -691,6 +718,8 @@ static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc, } else if (otype == DHCPV6_OPT_PREF && olen >= 1 && cand.preference >= 0) { cand.preference = pref = odata[0]; + } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(cand.server_addr)) { + cand.server_addr = *(struct in6_addr *)odata; } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) { cand.wants_reconfigure = true; } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) { @@ -765,6 +794,7 @@ static int dhcpv6_commit_advert(void) odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr)); odhcp6c_add_state(STATE_SERVER_ID, c->duid, c->duid_len); accept_reconfig = c->wants_reconfigure; + server_addr = c->server_addr; if (c->ia_na_len) odhcp6c_add_state(STATE_IA_NA, c->ia_na, c->ia_na_len); if (c->ia_pd_len) @@ -884,6 +914,8 @@ static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc, continue; dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr)); + } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(server_addr)) { + server_addr = *(struct in6_addr *)odata; } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) { uint8_t *mdata = (olen > 2) ? &odata[2] : NULL; uint16_t mlen = (olen > 2) ? olen - 2 : 0; @@ -1163,7 +1195,18 @@ static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig, break; case DHCPV6_UseMulticast: - // TODO handle multicast status code + switch(orig) { + case DHCPV6_MSG_REQUEST: + case DHCPV6_MSG_RENEW: + case DHCPV6_MSG_RELEASE: + case DHCPV6_MSG_DECLINE: + // Message needs to be retransmitted according to RFC3315 chapter 18.1.8 + server_addr = in6addr_any; + *ret = 0; + break; + default: + break; + } break; case DHCPV6_NoAddrsAvail: diff --git a/src/odhcp6c.c b/src/odhcp6c.c index de03b81..460f230 100644 --- a/src/odhcp6c.c +++ b/src/odhcp6c.c @@ -14,6 +14,7 @@ #include #include +#include #include #include #include @@ -22,12 +23,14 @@ #include #include #include +#include #include #include #include #include #include +#include #include "odhcp6c.h" #include "ra.h" @@ -36,6 +39,11 @@ #include "bfd.h" #endif +#ifndef IN6_IS_ADDR_UNIQUELOCAL +#define IN6_IS_ADDR_UNIQUELOCAL(a) \ + ((((__const uint32_t *) (a))[0] & htonl (0xfe000000)) \ + == htonl (0xfc000000)) +#endif static void sighandler(int signal); static int usage(void); @@ -47,7 +55,7 @@ static volatile int do_signal = 0; static int urandom_fd = -1, allow_slaac_only = 0; static bool bound = false, release = true; static time_t last_update = 0; - +static char *ifname = NULL; int main(_unused int argc, char* const argv[]) { @@ -171,7 +179,7 @@ int main(_unused int argc, char* const argv[]) } openlog("odhcp6c", logopt, LOG_DAEMON); - const char *ifname = argv[optind]; + ifname = argv[optind]; if (help || !ifname) return usage(); @@ -585,11 +593,64 @@ void odhcp6c_random(void *buf, size_t len) read(urandom_fd, buf, len); } + bool odhcp6c_is_bound(void) { return bound; } + +bool odhcp6c_addr_in_scope(const struct in6_addr *addr) +{ + FILE *fd = fopen("/proc/net/if_inet6", "r"); + int len; + char buf[256]; + + if (fd == NULL) + return false; + + while (fgets(buf, sizeof(buf), fd)) { + struct in6_addr inet6_addr; + uint32_t flags, dummy; + unsigned int i; + char name[8], addr_buf[32]; + + len = strlen(buf); + + if ((len <= 0) || buf[len - 1] != '\n') + return false; + + buf[--len] = '\0'; + + if (sscanf(buf, "%s %x %x %x %x %s", + addr_buf, &dummy, &dummy, &dummy, &flags, name) != 6) + return false; + + if (strcmp(name, ifname) || + (flags & (IFA_F_DADFAILED | IFA_F_TENTATIVE | IFA_F_DEPRECATED))) + continue; + + for (i = 0; i < sizeof(addr_buf); i++) { + if (!isxdigit(addr_buf[i]) || isupper(addr_buf[i])) + return false; + } + + memset(&inet6_addr, 0, sizeof(inet6_addr)); + for (i = 0; i < (sizeof(addr_buf) / 2); i++) { + unsigned char byte; + static const char hex[] = "0123456789abcdef"; + byte = ((index(hex, addr_buf[i * 2]) - hex) << 4) | + (index(hex, addr_buf[i * 2 + 1]) - hex); + inet6_addr.s6_addr[i] = byte; + } + + if ((IN6_IS_ADDR_LINKLOCAL(&inet6_addr) == IN6_IS_ADDR_LINKLOCAL(addr)) && + (IN6_IS_ADDR_UNIQUELOCAL(&inet6_addr) == IN6_IS_ADDR_UNIQUELOCAL(addr))) + return true; + } + return false; +} + static void sighandler(int signal) { if (signal == SIGCHLD) diff --git a/src/odhcp6c.h b/src/odhcp6c.h index 1a4fbce..cf8ff74 100644 --- a/src/odhcp6c.h +++ b/src/odhcp6c.h @@ -34,6 +34,7 @@ enum dhcvp6_opt { DHCPV6_OPT_ELAPSED = 8, DHCPV6_OPT_RELAY_MSG = 9, DHCPV6_OPT_AUTH = 11, + DHCPV6_OPT_UNICAST = 12, DHCPV6_OPT_STATUS = 13, DHCPV6_OPT_RAPID_COMMIT = 14, DHCPV6_OPT_RECONF_MESSAGE = 19, @@ -164,6 +165,7 @@ struct dhcpv6_server_cand { int16_t preference; uint8_t duid_len; uint8_t duid[130]; + struct in6_addr server_addr; void *ia_na; void *ia_pd; size_t ia_na_len; @@ -245,6 +247,7 @@ bool odhcp6c_signal_process(void); uint64_t odhcp6c_get_milli_time(void); void odhcp6c_random(void *buf, size_t len); bool odhcp6c_is_bound(void); +bool odhcp6c_addr_in_scope(const struct in6_addr *addr); // State manipulation void odhcp6c_clear_state(enum odhcp6c_state state); -- 2.39.2