X-Git-Url: http://git.archive.openwrt.org/?p=project%2Fodhcpd.git;a=blobdiff_plain;f=src%2Fdhcpv4.c;h=81e537d3ddbb8f4b7bc6e770e213c228ced1819f;hp=84690384db0fef14975d91f91b71fff12f72c908;hb=3d9f4067d56660a2c75ab2ce9b801ae1a4ff4cde;hpb=6c3bc0141dacc88992583d6f2cdc8a360df7422d diff --git a/src/dhcpv4.c b/src/dhcpv4.c index 8469038..81e537d 100644 --- a/src/dhcpv4.c +++ b/src/dhcpv4.c @@ -1,5 +1,6 @@ /** * Copyright (C) 2012-2013 Steven Barth + * Copyright (C) 2016 Hans Dedecker * * 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 @@ -32,43 +33,19 @@ #include "dhcpv4.h" #include "dhcpv6.h" - +static void free_dhcpv4_assignment(struct dhcpv4_assignment *a); static void handle_dhcpv4(void *addr, void *data, size_t len, struct interface *iface, void *dest_addr); static struct dhcpv4_assignment* dhcpv4_lease(struct interface *iface, enum dhcpv4_msg msg, const uint8_t *mac, struct in_addr reqaddr, - const char *hostname); + uint32_t *leasetime, const char *hostname, const size_t hostname_len); -// Create socket and register events +/* Create socket and register events */ int init_dhcpv4(void) { return 0; } -char *dhcpv4_msg_to_string(uint8_t reqmsg) -{ - switch (reqmsg) { - case (DHCPV4_MSG_DISCOVER): - return "DHCPV4_MSG_DISCOVER"; - case (DHCPV4_MSG_OFFER): - return "DHCPV4_MSG_OFFER"; - case (DHCPV4_MSG_REQUEST): - return "DHCPV4_MSG_REQUEST"; - case (DHCPV4_MSG_DECLINE): - return "DHCPV4_MSG_DECLINE"; - case (DHCPV4_MSG_ACK): - return "DHCPV4_MSG_ACK"; - case (DHCPV4_MSG_NAK): - return "DHCPV4_MSG_NAK"; - case (DHCPV4_MSG_RELEASE): - return "DHCPV4_MSG_RELEASE"; - case (DHCPV4_MSG_INFORM): - return "DHCPV4_MSG_INFORM"; - default: - return "UNKNOWN"; - } -} - int setup_dhcpv4_interface(struct interface *iface, bool enable) { if (iface->dhcpv4_event.uloop.fd > 0) { @@ -88,7 +65,7 @@ int setup_dhcpv4_interface(struct interface *iface, bool enable) return -1; } - // Basic IPv6 configuration + /* Basic IPv4 configuration */ int val = 1; setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val)); setsockopt(sock, SOL_SOCKET, SO_BROADCAST, &val, sizeof(val)); @@ -118,7 +95,7 @@ int setup_dhcpv4_interface(struct interface *iface, bool enable) return -1; } - // Create a range if not specified + /* Create a range if not specified */ struct ifreq ifreq; strncpy(ifreq.ifr_name, iface->ifname, sizeof(ifreq.ifr_name)); @@ -165,73 +142,100 @@ int setup_dhcpv4_interface(struct interface *iface, bool enable) } - // Parse static entries + /* Parse static entries */ struct lease *lease; list_for_each_entry(lease, &leases, head) { - // Construct entry - size_t hostlen = strlen(lease->hostname) + 1; - struct dhcpv4_assignment *a = calloc(1, sizeof(*a) + hostlen); + /* Construct entry */ + struct dhcpv4_assignment *a = calloc(1, sizeof(*a)); if (!a) { syslog(LOG_ERR, "Calloc failed for static lease on interface %s", iface->ifname); return -1; } - if (lease->dhcpv4_leasetime >= 60) - a->leasetime = lease->dhcpv4_leasetime; + + a->leasetime = lease->dhcpv4_leasetime; + a->addr = ntohl(lease->ipaddr.s_addr); memcpy(a->hwaddr, lease->mac.ether_addr_octet, sizeof(a->hwaddr)); - memcpy(a->hostname, lease->hostname, hostlen); + /* Static assignment */ + a->flags |= OAF_STATIC; /* Infinite valid */ a->valid_until = 0; - // Assign to all interfaces + /* Assign to all interfaces */ struct dhcpv4_assignment *c; list_for_each_entry(c, &iface->dhcpv4_assignments, head) { if (c->addr > a->addr) { list_add_tail(&a->head, &c->head); break; - } else if (c->addr == a->addr) { - // Already an assignment with that number + } else if (c->addr == a->addr) + /* Already an assignment with that number */ break; - } } - if (&c->head == &iface->dhcpv4_assignments) { + + if (&c->head == &iface->dhcpv4_assignments) list_add(&a->head, &iface->dhcpv4_assignments); - } - if (!a->head.next) - free(a); + if (a->head.next) { + if (lease->hostname[0]) { + free(a->hostname); + a->hostname = strdup(lease->hostname); + } + } else + free_dhcpv4_assignment(a); } // Clean invalid assignments struct dhcpv4_assignment *a, *n; list_for_each_entry_safe(a, n, &iface->dhcpv4_assignments, head) { if ((htonl(a->addr) & smask->sin_addr.s_addr) != - (iface->dhcpv4_start.s_addr & smask->sin_addr.s_addr)) { - list_del(&a->head); - free(a); - } + (iface->dhcpv4_start.s_addr & smask->sin_addr.s_addr)) + free_dhcpv4_assignment(a); } - - if (iface->dhcpv4_leasetime < 60) - iface->dhcpv4_leasetime = 43200; - iface->dhcpv4_event.uloop.fd = sock; iface->dhcpv4_event.handle_dgram = handle_dhcpv4; odhcpd_register(&iface->dhcpv4_event); } else if (iface->dhcpv4_assignments.next) { - while (!list_empty(&iface->dhcpv4_assignments)) { - struct dhcpv4_assignment *a = list_first_entry(&iface->dhcpv4_assignments, - struct dhcpv4_assignment, head); - list_del(&a->head); - free(a); - } - + while (!list_empty(&iface->dhcpv4_assignments)) + free_dhcpv4_assignment(list_first_entry(&iface->dhcpv4_assignments, + struct dhcpv4_assignment, head)); } return 0; } +static char *dhcpv4_msg_to_string(uint8_t reqmsg) +{ + switch (reqmsg) { + case (DHCPV4_MSG_DISCOVER): + return "DHCPV4_MSG_DISCOVER"; + case (DHCPV4_MSG_OFFER): + return "DHCPV4_MSG_OFFER"; + case (DHCPV4_MSG_REQUEST): + return "DHCPV4_MSG_REQUEST"; + case (DHCPV4_MSG_DECLINE): + return "DHCPV4_MSG_DECLINE"; + case (DHCPV4_MSG_ACK): + return "DHCPV4_MSG_ACK"; + case (DHCPV4_MSG_NAK): + return "DHCPV4_MSG_NAK"; + case (DHCPV4_MSG_RELEASE): + return "DHCPV4_MSG_RELEASE"; + case (DHCPV4_MSG_INFORM): + return "DHCPV4_MSG_INFORM"; + default: + return "UNKNOWN"; + } +} + +static void free_dhcpv4_assignment(struct dhcpv4_assignment *a) +{ + if (a->head.next) + list_del(&a->head); + + free(a->hostname); + free(a); +} static void dhcpv4_put(struct dhcpv4_message *msg, uint8_t **cookie, uint8_t type, uint8_t len, const void *data) @@ -312,21 +316,23 @@ static void handle_dhcpv4(void *addr, void *data, size_t len, uint8_t msg = DHCPV4_MSG_ACK; struct in_addr reqaddr = {INADDR_ANY}; + uint32_t leasetime = 0; + size_t hostname_len = 0; char hostname[256]; - hostname[0] = 0; uint8_t *start = &req->options[4]; uint8_t *end = ((uint8_t*)data) + len; struct dhcpv4_option *opt; dhcpv4_for_each_option(start, end, opt) { - if (opt->type == DHCPV4_OPT_MESSAGE && opt->len == 1) { + if (opt->type == DHCPV4_OPT_MESSAGE && opt->len == 1) reqmsg = opt->data[0]; - } else if (opt->type == DHCPV4_OPT_HOSTNAME && opt->len > 0) { - memcpy(hostname, opt->data, opt->len); - hostname[opt->len] = 0; - } else if (opt->type == DHCPV4_OPT_IPADDRESS && opt->len == 4) { + else if (opt->type == DHCPV4_OPT_HOSTNAME && opt->len > 0) { + hostname_len = opt->len; + memcpy(hostname, opt->data, hostname_len); + hostname[hostname_len] = 0; + } else if (opt->type == DHCPV4_OPT_IPADDRESS && opt->len == 4) memcpy(&reqaddr, opt->data, 4); - } else if (opt->type == DHCPV4_OPT_SERVERID && opt->len == 4) { + else if (opt->type == DHCPV4_OPT_SERVERID && opt->len == 4) { if (memcmp(opt->data, &ifaddr.sin_addr, 4)) return; } else if (iface->filter_class && opt->type == DHCPV4_OPT_USER_CLASS) { @@ -336,7 +342,8 @@ static void handle_dhcpv4(void *addr, void *data, size_t len, if (*c == elen && !memcmp(&c[1], iface->filter_class, elen)) return; // Ignore from homenet } - } + } else if (opt->type == DHCPV4_OPT_LEASETIME && opt->len == 4) + memcpy(&leasetime, opt->data, 4); } if (reqmsg != DHCPV4_MSG_DISCOVER && reqmsg != DHCPV4_MSG_REQUEST && @@ -346,16 +353,17 @@ static void handle_dhcpv4(void *addr, void *data, size_t len, struct dhcpv4_assignment *lease = NULL; if (reqmsg != DHCPV4_MSG_INFORM) - lease = dhcpv4_lease(iface, reqmsg, req->chaddr, reqaddr, hostname); + lease = dhcpv4_lease(iface, reqmsg, req->chaddr, reqaddr, + &leasetime, hostname, hostname_len); if (!lease) { if (reqmsg == DHCPV4_MSG_REQUEST) msg = DHCPV4_MSG_NAK; else if (reqmsg == DHCPV4_MSG_DISCOVER) return; - } else if (reqmsg == DHCPV4_MSG_DISCOVER) { + } else if (reqmsg == DHCPV4_MSG_DISCOVER) msg = DHCPV4_MSG_OFFER; - } else if (reqmsg == DHCPV4_MSG_REQUEST && reqaddr.s_addr && + else if (reqmsg == DHCPV4_MSG_REQUEST && reqaddr.s_addr && reqaddr.s_addr != htonl(lease->addr)) { msg = DHCPV4_MSG_NAK; /* @@ -382,16 +390,9 @@ static void handle_dhcpv4(void *addr, void *data, size_t len, dhcpv4_put(&reply, &cookie, DHCPV4_OPT_SERVERID, 4, &ifaddr.sin_addr); if (lease) { - reply.yiaddr.s_addr = htonl(lease->addr); - uint32_t val; - uint32_t leasetime; - if (lease->leasetime >= 60) { - leasetime = lease->leasetime; - } else { - leasetime = iface->dhcpv4_leasetime; - } + reply.yiaddr.s_addr = htonl(lease->addr); val = htonl(leasetime); dhcpv4_put(&reply, &cookie, DHCPV4_OPT_LEASETIME, 4, &val); @@ -406,7 +407,7 @@ static void handle_dhcpv4(void *addr, void *data, size_t len, dhcpv4_put(&reply, &cookie, DHCPV4_OPT_NETMASK, 4, &ifnetmask.sin_addr); - if (lease->hostname[0]) + if (lease->hostname) dhcpv4_put(&reply, &cookie, DHCPV4_OPT_HOSTNAME, strlen(lease->hostname), lease->hostname); @@ -421,10 +422,10 @@ static void handle_dhcpv4(void *addr, void *data, size_t len, dhcpv4_put(&reply, &cookie, DHCPV4_OPT_MTU, 2, &mtu); } - if (iface->search && iface->search_len <= 255) { + if (iface->search && iface->search_len <= 255) dhcpv4_put(&reply, &cookie, DHCPV4_OPT_SEARCH_DOMAIN, iface->search_len, iface->search); - } else if (!res_init() && _res.dnsrch[0] && _res.dnsrch[0][0]) { + else if (!res_init() && _res.dnsrch[0] && _res.dnsrch[0][0]) { uint8_t search_buf[256]; int len = dn_comp(_res.dnsrch[0], search_buf, sizeof(search_buf), NULL, NULL); @@ -491,14 +492,12 @@ static void handle_dhcpv4(void *addr, void *data, size_t len, ioctl(sock, SIOCSARP, &arp); } - if (dest.sin_addr.s_addr == INADDR_BROADCAST) { - /* - * reply goes to IP broadcast -> MAC broadcast - */ + if (dest.sin_addr.s_addr == INADDR_BROADCAST) + /* reply goes to IP broadcast -> MAC broadcast */ syslog(LOG_WARNING, "sending %s to ff:ff:ff:ff:ff:ff - %s", dhcpv4_msg_to_string(msg), inet_ntoa(dest.sin_addr)); - } else { + else /* * reply is send directly to IP, * MAC is assumed to be the same as the request @@ -508,7 +507,6 @@ static void handle_dhcpv4(void *addr, void *data, size_t len, req->chaddr[0],req->chaddr[1],req->chaddr[2], req->chaddr[3],req->chaddr[4],req->chaddr[5], inet_ntoa(dest.sin_addr)); - } sendto(sock, &reply, sizeof(reply), MSG_DONTWAIT, (struct sockaddr*)&dest, sizeof(dest)); @@ -518,10 +516,11 @@ static bool dhcpv4_test(struct interface *iface, uint32_t try) { struct dhcpv4_assignment *c; list_for_each_entry(c, &iface->dhcpv4_assignments, head) { - if (c->addr == try) { + if (c->addr == try) return false; - } + } + return true; } @@ -536,7 +535,7 @@ static bool dhcpv4_assign(struct interface *iface, if (start <= raddr && raddr <= end && dhcpv4_test(iface, raddr)) { assign->addr = raddr; list_add(&assign->head, &iface->dhcpv4_assignments); - syslog(LOG_DEBUG, "assigning the IP the client asked for: %u.%u.%u.%u", + syslog(LOG_INFO, "assigning the IP the client asked for: %u.%u.%u.%u", (assign->addr & 0xff000000) >> 24, (assign->addr & 0x00ff0000) >> 16, (assign->addr & 0x0000ff00) >> 8, @@ -551,6 +550,7 @@ static bool dhcpv4_assign(struct interface *iface, uint8_t o = assign->hwaddr[i]; seed += (o*2654435761) % UINT32_MAX; } + srand(seed); uint32_t try = (((uint32_t)rand()) % count) + start; @@ -558,7 +558,7 @@ static bool dhcpv4_assign(struct interface *iface, if (list_empty(&iface->dhcpv4_assignments)) { assign->addr = try; list_add(&assign->head, &iface->dhcpv4_assignments); - syslog(LOG_DEBUG, "assigning mapped IP (empty list): %u.%u.%u.%u", + syslog(LOG_INFO, "assigning mapped IP (empty list): %u.%u.%u.%u", (assign->addr & 0xff000000) >> 24, (assign->addr & 0x00ff0000) >> 16, (assign->addr & 0x0000ff00) >> 8, @@ -581,14 +581,14 @@ static bool dhcpv4_assign(struct interface *iface, try = (((try - start) + 1) % count) + start; } - syslog(LOG_DEBUG, "can't assign any IP address -> address space is full"); + syslog(LOG_WARNING, "can't assign any IP address -> address space is full"); return false; } static struct dhcpv4_assignment* dhcpv4_lease(struct interface *iface, enum dhcpv4_msg msg, const uint8_t *mac, struct in_addr reqaddr, - const char *hostname) + uint32_t *leasetime, const char *hostname, const size_t hostname_len) { struct dhcpv4_assignment *lease = NULL; uint32_t raddr = ntohl(reqaddr.s_addr); @@ -600,69 +600,80 @@ static struct dhcpv4_assignment* dhcpv4_lease(struct interface *iface, a = c; if (c->addr == raddr) break; - } else if (!INFINITE_VALID(c->valid_until) && c->valid_until < now) { - list_del(&c->head); - free(c); - } + } else if (!INFINITE_VALID(c->valid_until) && c->valid_until < now) + free_dhcpv4_assignment(c); } if (msg == DHCPV4_MSG_DISCOVER || msg == DHCPV4_MSG_REQUEST) { bool assigned = !!a; - size_t hostlen = strlen(hostname) + 1; + uint32_t my_leasetime; - if (!a && !iface->no_dynamic_dhcp) { // Create new binding - a = calloc(1, sizeof(*a) + hostlen); + if (!a && !iface->no_dynamic_dhcp) { + /* Create new binding */ + a = calloc(1, sizeof(*a)); if (!a) { syslog(LOG_ERR, "Failed to calloc binding on interface %s", iface->ifname); return NULL; } memcpy(a->hwaddr, mac, sizeof(a->hwaddr)); - memcpy(a->hostname, hostname, hostlen); + /* Don't consider new assignment as infinite */ + a->valid_until = now; assigned = dhcpv4_assign(iface, a, raddr); } - if (assigned && !a->hostname[0] && hostname) { - a = realloc(a, sizeof(*a) + hostlen); - if (!a) { - syslog(LOG_ERR, "Failed to realloc binding on interface %s", iface->ifname); - return NULL; - } - memcpy(a->hostname, hostname, hostlen); - - // Fixup list - a->head.next->prev = &a->head; - a->head.prev->next = &a->head; - } + if (a->leasetime) + my_leasetime = a->leasetime; + else + my_leasetime = iface->dhcpv4_leasetime; + + if ((*leasetime == 0) || (my_leasetime < *leasetime)) + *leasetime = my_leasetime; + + if (assigned) { + if (msg == DHCPV4_MSG_DISCOVER) { + a->flags &= ~OAF_BOUND; + + if (!(a->flags & OAF_STATIC)) + a->valid_until = now; + } else { + if (hostname_len > 0) { + a->hostname = realloc(a->hostname, hostname_len + 1); + if (a->hostname) { + memcpy(a->hostname, hostname, hostname_len); + a->hostname[hostname_len] = 0; + } + } - uint32_t leasetime; - if (a->leasetime) { - leasetime = a->leasetime; - } else { - leasetime = iface->dhcpv4_leasetime; - } + a->flags |= OAF_BOUND; - // Was only a discover; mark binding for removal - if (assigned && a->valid_until < now) { - a->valid_until = ((msg == DHCPV4_MSG_DISCOVER) ? now : ((leasetime == UINT32_MAX) ? - 0 : (time_t)(now + leasetime))); - } else if (!assigned && a) { // Cleanup failed assignment - free(a); + if (!(a->flags & OAF_STATIC)) + a->valid_until = ((*leasetime == UINT32_MAX) ? 0 : (time_t)(now + *leasetime)); + } + } else if (!assigned && a) { + /* Cleanup failed assignment */ + free_dhcpv4_assignment(a); a = NULL; } if (assigned && a) lease = a; - } else if (msg == DHCPV4_MSG_RELEASE) { - if (a && !INFINITE_VALID(a->valid_until)) + } else if (msg == DHCPV4_MSG_RELEASE && a) { + a->flags &= ~OAF_BOUND; + + if (!(a->flags & OAF_STATIC)) a->valid_until = now - 1; - } else if (msg == DHCPV4_MSG_DECLINE && a && !INFINITE_VALID(a->valid_until)) { - memset(a->hwaddr, 0, sizeof(a->hwaddr)); - a->valid_until = now + 3600; // Block address for 1h + + } else if (msg == DHCPV4_MSG_DECLINE && a) { + a->flags &= ~OAF_BOUND; + + if (!(a->flags & OAF_STATIC)) { + memset(a->hwaddr, 0, sizeof(a->hwaddr)); + a->valid_until = now + 3600; /* Block address for 1h */ + } } dhcpv6_write_statefile(); return lease; } -