--- /dev/null
+/*
+ * dhcp.c Functions to send/receive dhcp packets.
+ *
+ * Version: $Id$
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ *
+ * Copyright 2008 The FreeRADIUS server project
+ * Copyright 2008 Alan DeKok <aland@deployingradius.com>
+ */
+
+#include <freeradius-devel/ident.h>
+RCSID("$Id$")
+
+#include <freeradius-devel/libradius.h>
+#include <freeradius-devel/udpfromto.h>
+#include <freeradius-devel/dhcp.h>
+
+#ifdef WITH_DHCP
+#define DHCP_CHADDR_LEN (16)
+#define DHCP_SNAME_LEN (64)
+#define DHCP_FILE_LEN (128)
+#define DHCP_VEND_LEN (308)
+#define DHCP_OPTION_MAGIC_NUMBER (0x63825363)
+
+typedef struct dhcp_packet_t {
+ uint8_t opcode;
+ uint8_t htype;
+ uint8_t hlen;
+ uint8_t hops;
+ uint32_t xid; /* 4 */
+ uint16_t secs; /* 8 */
+ uint16_t flags;
+ uint32_t ciaddr; /* 12 */
+ uint32_t yiaddr; /* 16 */
+ uint32_t siaddr; /* 20 */
+ uint32_t giaddr; /* 24 */
+ uint8_t chaddr[DHCP_CHADDR_LEN]; /* 28 */
+ char sname[DHCP_SNAME_LEN]; /* 44 */
+ char file[DHCP_FILE_LEN]; /* 108 */
+ uint32_t option_format; /* 236 */
+ uint8_t options[DHCP_VEND_LEN];
+} dhcp_packet_t;
+
+/*
+ * INADDR_ANY : 68 -> INADDR_BROADCAST : 67 DISCOVER
+ * INADDR_BROADCAST : 68 <- SERVER_IP : 67 OFFER
+ * INADDR_ANY : 68 -> INADDR_BROADCAST : 67 REQUEST
+ * INADDR_BROADCAST : 68 <- SERVER_IP : 67 ACK
+ */
+static const char *dhcp_header_names[] = {
+ "DHCP-Opcode",
+ "DHCP-Hardware-Type",
+ "DHCP-Hardware-Address-Length",
+ "DHCP-Hop-Count",
+ "DHCP-Transaction-Id",
+ "DHCP-Number-of-Seconds",
+ "DHCP-Flags",
+ "DHCP-Client-IP-Address",
+ "DHCP-Your-IP-Address",
+ "DHCP-Server-IP-Address",
+ "DHCP-Gateway-IP-Address",
+ "DHCP-Client-Hardware-Address",
+ "DHCP-Server-Host-Name",
+ "DHCP-Boot-Filename",
+
+ NULL
+};
+
+static const char *dhcp_message_types[] = {
+ "invalid",
+ "DHCP-Discover",
+ "DHCP-Offer",
+ "DHCP-Request",
+ "DHCP-Decline",
+ "DHCP-Ack",
+ "DHCP-NAK",
+ "DHCP-Release",
+ "DHCP-Inform",
+ "DHCP-Force-Renew",
+};
+
+static int dhcp_header_sizes[] = {
+ 1, 1, 1, 1,
+ 4, 2, 2, 4,
+ 4, 4, 4,
+ DHCP_CHADDR_LEN,
+ DHCP_SNAME_LEN,
+ DHCP_FILE_LEN
+};
+
+
+/*
+ * Some clients silently ignore responses less than 300 bytes.
+ */
+#define MIN_PACKET_SIZE (244)
+#define DEFAULT_PACKET_SIZE (576)
+#define MAX_PACKET_SIZE (1500 - 40)
+
+/*
+ * DHCPv4 is only for IPv4. Broadcast only works if udpfromto is
+ * defined.
+ */
+RADIUS_PACKET *fr_dhcp_recv(int sockfd)
+{
+ uint32_t magic;
+ struct sockaddr_storage src;
+ struct sockaddr_storage dst;
+ socklen_t sizeof_src = sizeof(src);
+ socklen_t sizeof_dst = sizeof(dst);
+ RADIUS_PACKET *packet;
+
+ memset(&src, 0, sizeof_src);
+ memset(&dst, 0, sizeof_dst);
+
+ packet = rad_alloc(0);
+ if (!packet) return NULL;
+ memset(packet, 0, sizeof(packet));
+
+ packet->data = malloc(MAX_PACKET_SIZE);
+ if (!packet->data) {
+ rad_free(&packet);
+ return NULL;
+ }
+
+ packet->sockfd = sockfd;
+ packet->data_len = recvfrom(sockfd, packet->data, MAX_PACKET_SIZE, 0,
+ (struct sockaddr *)&src, &sizeof_src);
+ if (packet->data_len <= 0) {
+ fprintf(stderr, "Failed reading DHCP socket: %s", strerror(errno));
+ rad_free(&packet);
+ return NULL;
+ }
+
+ if (packet->data_len < MIN_PACKET_SIZE) {
+ fprintf(stderr, "DHCP packet is too small (%d < %d)",
+ packet->data_len, MIN_PACKET_SIZE);
+ rad_free(&packet);
+ return NULL;
+ }
+
+ if (packet->data[0] != 1) {
+ fprintf(stderr, "Cannot receive DHCP server messages");
+ rad_free(&packet);
+ return NULL;
+ }
+
+ if (packet->data[1] != 1) {
+ fprintf(stderr, "DHCP can only receive ethernet requests, not type %02x",
+ packet->data[1]);
+ rad_free(&packet);
+ return NULL;
+ }
+
+ if (packet->data[2] != 6) {
+ fprintf(stderr, "Ethernet HW length is wrong length %d\n",
+ packet->data[2]);
+ rad_free(&packet);
+ return NULL;
+ }
+
+ memcpy(&magic, packet->data + 236, 4);
+ magic = ntohl(magic);
+ if (magic != DHCP_OPTION_MAGIC_NUMBER) {
+ fprintf(stderr, "Cannot do BOOTP\n");
+ rad_free(&packet);
+ return NULL;
+ }
+
+ /*
+ * Create unique keys for the packet.
+ */
+ memcpy(&magic, packet->data + 4, 4);
+ packet->id = ntohl(magic);
+
+ /*
+ * Check that it's a known packet type.
+ */
+ if ((packet->data[240] != 53) ||
+ (packet->data[241] != 1) ||
+ (packet->data[242] == 0) ||
+ (packet->data[242] >= 8)) {
+ fprintf(stderr, "Unknown, or badly formatted DHCP packet\n");
+ rad_free(&packet);
+ return NULL;
+ }
+
+ /*
+ * Create a unique vector from the MAC address and the
+ * DHCP opcode. This is a hack for the RADIUS
+ * infrastructure in the rest of the server.
+ *
+ * Note: packet->data[2] == 6, which is smaller than
+ * sizeof(packet->vector)
+ *
+ * FIXME: Look for client-identifier in packet,
+ * and use that, too?
+ */
+ memset(packet->vector, 0, sizeof(packet->vector));
+ memcpy(packet->vector, packet->data + 28, packet->data[2]);
+ packet->vector[packet->data[2]] = packet->data[242];
+
+ /*
+ * FIXME: for DISCOVER / REQUEST: src_port == dst_port + 1
+ * FIXME: for OFFER / ACK : src_port = dst_port - 1
+ */
+
+ packet->code = PW_DHCP_OFFSET | packet->data[242];
+
+ /*
+ * Unique keys are xid, client mac, and client ID?
+ */
+
+ /*
+ * FIXME: More checks, like DHCP packet type?
+ */
+
+ {
+ struct sockaddr_in *s4;
+ struct sockaddr_storage si;
+ socklen_t si_len = sizeof(si);
+
+ /*
+ * This should never fail...
+ */
+ getsockname(sockfd, (struct sockaddr *) &si, &si_len);
+
+ s4 = (struct sockaddr_in *)&src;
+ packet->src_ipaddr.af = AF_INET;
+ packet->src_ipaddr.ipaddr.ip4addr = s4->sin_addr;
+ packet->src_port = ntohs(s4->sin_port);
+
+ s4 = (struct sockaddr_in *)&si;
+ packet->dst_ipaddr.af = AF_INET;
+ packet->dst_ipaddr.ipaddr.ip4addr = s4->sin_addr;
+ packet->dst_port = ntohs(s4->sin_port);
+ }
+
+ if (librad_debug > 1) {
+ char type_buf[64];
+ const char *name = type_buf;
+ char src_ip_buf[256], dst_ip_buf[256];
+
+ if ((packet->code >= PW_DHCP_DISCOVER) &&
+ (packet->code <= PW_DHCP_INFORM)) {
+ name = dhcp_message_types[packet->code - PW_DHCP_OFFSET];
+ } else {
+ snprintf(type_buf, sizeof(type_buf), "%d",
+ packet->code - PW_DHCP_OFFSET);
+ }
+
+ printf("Received %s of id %u from %s:%d to %s:%d\n",
+ name, (unsigned int) packet->id,
+ inet_ntop(packet->src_ipaddr.af,
+ &packet->src_ipaddr.ipaddr,
+ src_ip_buf, sizeof(src_ip_buf)),
+ packet->src_port,
+ inet_ntop(packet->dst_ipaddr.af,
+ &packet->dst_ipaddr.ipaddr,
+ dst_ip_buf, sizeof(dst_ip_buf)),
+ packet->dst_port);
+ fflush(stdout);
+ }
+
+ return packet;
+}
+
+
+/*
+ * Send a DHCP packet.
+ */
+int fr_dhcp_send(RADIUS_PACKET *packet)
+{
+ struct sockaddr_storage dst;
+ struct sockaddr_storage src;
+ socklen_t sizeof_dst = sizeof(dst);
+ socklen_t sizeof_src = sizeof(src);
+
+ memset(&src, 0, sizeof(src));
+ memset(&dst, 0, sizeof(dst));
+
+ /*
+ * Only IPv4 is supported.
+ */
+ {
+ struct sockaddr_in *s4;
+
+ s4 = (struct sockaddr_in *)&dst;
+ sizeof_dst = sizeof(struct sockaddr_in);
+
+ s4->sin_family = AF_INET;
+ s4->sin_addr = packet->dst_ipaddr.ipaddr.ip4addr;
+ s4->sin_port = htons(packet->dst_port);
+
+ s4 = (struct sockaddr_in *)&src;
+ sizeof_src = sizeof(struct sockaddr_in);
+
+ s4->sin_family = AF_INET;
+ s4->sin_addr = packet->src_ipaddr.ipaddr.ip4addr;
+ s4->sin_port = htons(packet->src_port);
+ }
+
+ /*
+ * Assume that the packet is encoded before sending it.
+ */
+ return sendto(packet->sockfd, packet->data, packet->data_len, 0,
+ (struct sockaddr *)&dst, sizeof_dst);
+}
+
+
+int fr_dhcp_decode(RADIUS_PACKET *packet)
+{
+ int i;
+ ssize_t total;
+ uint8_t *p;
+ uint32_t giaddr;
+ VALUE_PAIR *head, *vp, **tail;
+ VALUE_PAIR *maxms, *mtu;
+ char buffer[2048];
+
+ head = NULL;
+ tail = &head;
+ p = packet->data;
+
+ if ((librad_debug > 2) && fr_log_fp) {
+ for (i = 0; i < packet->data_len; i++) {
+ if ((i & 0x0f) == 0x00) fprintf(stderr, "%d: ", i);
+ fprintf(fr_log_fp, "%02x ", packet->data[i]);
+ if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
+ }
+ fprintf(fr_log_fp, "\n");
+ }
+
+ if (packet->data[1] != 1) {
+ fprintf(stderr, "Packet is not Ethernet: %u\n",
+ packet->data[1]);
+ return -1;
+ }
+
+ /*
+ * Decode the header.
+ */
+ for (i = 0; i < 14; i++) {
+ vp = pairmake(dhcp_header_names[i], NULL, T_OP_EQ);
+ if (!vp) {
+ fprintf(stderr, "Parse error %s\n", librad_errstr);
+ pairfree(&head);
+ return -1;
+ }
+
+
+ if ((i == 11) &&
+ (packet->data[1] == 1) &&
+ (packet->data[2] == 6)) {
+ vp->type = PW_TYPE_ETHERNET;
+ }
+
+ switch (vp->type) {
+ case PW_TYPE_BYTE:
+ vp->vp_integer = p[0];
+ vp->length = 1;
+ break;
+
+ case PW_TYPE_SHORT:
+ vp->vp_integer = (p[0] << 8) | p[1];
+ vp->length = 2;
+ break;
+
+ case PW_TYPE_INTEGER:
+ memcpy(&vp->vp_integer, p, 4);
+ vp->vp_integer = ntohl(vp->vp_integer);
+ vp->length = 4;
+ break;
+
+ case PW_TYPE_IPADDR:
+ memcpy(&vp->vp_ipaddr, p, 4);
+ vp->length = 4;
+ break;
+
+ case PW_TYPE_STRING:
+ memcpy(vp->vp_strvalue, p, dhcp_header_sizes[i]);
+ vp->vp_strvalue[dhcp_header_sizes[i]] = '\0';
+ vp->length = strlen(vp->vp_strvalue);
+ if (vp->length == 0) {
+ pairfree(&vp);
+ }
+ break;
+
+ case PW_TYPE_OCTETS:
+ memcpy(vp->vp_octets, p, packet->data[2]);
+ vp->length = packet->data[2];
+ break;
+
+ case PW_TYPE_ETHERNET:
+ memcpy(vp->vp_ether, p, packet->data[2]);
+ vp->length = packet->data[2];
+ break;
+
+ default:
+ fprintf(stderr, "BAD TYPE %d\n", vp->type);
+ pairfree(&vp);
+ break;
+ }
+ p += dhcp_header_sizes[i];
+
+ if (!vp) continue;
+
+ if (librad_debug > 1) {
+ vp_prints(buffer, sizeof(buffer), vp);
+ fprintf(stderr, "\t%s\n", buffer);
+ }
+ *tail = vp;
+ tail = &vp->next;
+ }
+
+ /*
+ * Loop over the options.
+ */
+ p = packet->data + 240;
+ total = packet->data_len - 240;
+
+ while (total > 0) {
+ int num_entries, alen;
+ DICT_ATTR *da;
+
+ if (*p == 0) break;
+ if (*p == 255) break; /* end of options signifier */
+
+ if (p[1] >= 253) {
+ fprintf(stderr, "Attribute too long %u %u\n",
+ p[0], p[1]);
+ goto do_next;
+ }
+
+ da = dict_attrbyvalue(DHCP2ATTR(p[0]));
+ if (!da) {
+ fprintf(stderr, "Attribute not in our dictionary: %u\n",
+ p[0]);
+ do_next:
+ total -= 2;
+ total -= p[1];
+ p += p[1];
+ p += 2;
+ continue;
+ }
+
+ vp = NULL;
+ num_entries = 1;
+ alen = p[1];
+ p += 2;
+
+ if (da->flags.array) {
+ switch (da->type) {
+ case PW_TYPE_BYTE:
+ num_entries = alen;
+ alen = 1;
+ break;
+
+ case PW_TYPE_SHORT:
+ if ((alen & 0x01) != 0) goto raw;
+ num_entries = alen / 2;
+ alen = 2;
+ break;
+
+ case PW_TYPE_IPADDR:
+ case PW_TYPE_INTEGER:
+ case PW_TYPE_DATE:
+ if ((alen & 0x03) != 0) goto raw;
+ num_entries = alen / 4;
+ alen = 4;
+ break;
+
+ default:
+ break; /* really an internal sanity failure */
+ }
+ } else {
+ num_entries = 1;
+
+ switch (da->type) {
+ case PW_TYPE_BYTE:
+ if (alen != 1) goto raw;
+ break;
+
+ case PW_TYPE_SHORT:
+ if (alen != 2) goto raw;
+ break;
+
+ case PW_TYPE_IPADDR:
+ case PW_TYPE_INTEGER:
+ case PW_TYPE_DATE:
+ if (alen != 4) goto raw;
+ break;
+
+ default:
+ break;
+ }
+ }
+
+ for (i = 0; i < num_entries; i++) {
+ vp = pairmake(da->name, NULL, T_OP_EQ);
+ if (!vp) {
+ fprintf(stderr, "Cannot build attribute %s\n",
+ librad_errstr);
+ pairfree(&head);
+ return -1;
+ }
+
+ /*
+ * Hacks for ease of use.
+ */
+ if ((da->attr == DHCP2ATTR(0x3d)) &&
+ !da->flags.array &&
+ (alen == 7) && (*p == 1) && (num_entries == 1)) {
+ vp->type = PW_TYPE_ETHERNET;
+ memcpy(vp->vp_octets, p + 1, 6);
+ } else
+
+ switch (vp->type) {
+ case PW_TYPE_BYTE:
+ vp->vp_integer = p[0];
+ break;
+
+ case PW_TYPE_SHORT:
+ vp->vp_integer = (p[0] << 8) | p[1];
+ break;
+
+ case PW_TYPE_INTEGER:
+ memcpy(&vp->vp_integer, p, 4);
+ vp->vp_integer = ntohl(vp->vp_integer);
+ break;
+
+ case PW_TYPE_IPADDR:
+ memcpy(&vp->vp_ipaddr, p , 4);
+ vp->length = 4;
+ break;
+
+ case PW_TYPE_STRING:
+ memcpy(vp->vp_strvalue, p , alen);
+ vp->vp_strvalue[alen] = '\0';
+ break;
+
+ raw:
+ vp = pairmake(da->name, NULL, T_OP_EQ);
+ if (!vp) {
+ fprintf(stderr, "Cannot build attribute %s\n", librad_errstr);
+ pairfree(&head);
+ return -1;
+ }
+
+ vp->type = PW_TYPE_OCTETS;
+
+ case PW_TYPE_OCTETS:
+ memcpy(vp->vp_octets, p, alen);
+ break;
+
+ default:
+ fprintf(stderr, "Internal sanity check %d %d\n", vp->type, __LINE__);
+ pairfree(&vp);
+ break;
+ } /* switch over type */
+
+ vp->length = alen;
+
+ if (librad_debug > 1) {
+ vp_prints(buffer, sizeof(buffer), vp);
+ fprintf(stderr, "\t%s\n", buffer);
+ }
+
+ *tail = vp;
+ tail = &vp->next;
+ p += alen;
+ } /* loop over array entries */
+
+ total -= 2;
+ total -= (alen * num_entries);
+ }
+
+ /*
+ * If DHCP request, set ciaddr to zero.
+ */
+
+ /*
+ * Set broadcast flag for broken vendors, but only if
+ * giaddr isn't set.
+ */
+ memcpy(&giaddr, packet->data + 24, sizeof(giaddr));
+ if (giaddr == htonl(INADDR_ANY)) {
+ /*
+ * DHCP Opcode is request
+ */
+ vp = pairfind(head, DHCP2ATTR(256));
+ if (vp && vp->lvalue == 3) {
+ /*
+ * Vendor is "MSFT 98"
+ */
+ vp = pairfind(head, DHCP2ATTR(63));
+ if (vp && (strcmp(vp->vp_strvalue, "MSFT 98") == 0)) {
+ vp = pairfind(head, DHCP2ATTR(262));
+
+ /*
+ * Reply should be broadcast.
+ */
+ if (vp) vp->lvalue |= 0x8000;
+ packet->data[10] |= 0x80;
+ }
+ }
+ }
+
+ /*
+ * FIXME: Nuke attributes that aren't used in the normal
+ * header for discover/requests.
+ */
+ packet->vps = head;
+
+ /*
+ * Client can request a LARGER size, but not a smaller
+ * one. They also cannot request a size larger than MTU.
+ */
+ maxms = pairfind(packet->vps, DHCP2ATTR(57));
+ mtu = pairfind(packet->vps, DHCP2ATTR(26));
+
+ if (mtu && (mtu->vp_integer < DEFAULT_PACKET_SIZE)) {
+ fprintf(stderr, "DHCP Fatal: Client says MTU is smaller than minimum permitted by the specification.");
+ return -1;
+ }
+
+ if (maxms && (maxms->vp_integer < DEFAULT_PACKET_SIZE)) {
+ fprintf(stderr, "DHCP WARNING: Client says maximum message size is smaller than minimum permitted by the specification: fixing it");
+ maxms->vp_integer = DEFAULT_PACKET_SIZE;
+ }
+
+ if (maxms && mtu && (maxms->vp_integer > mtu->vp_integer)) {
+ fprintf(stderr, "DHCP WARNING: Client says MTU is smaller than maximum message size: fixing it");
+ maxms->vp_integer = mtu->vp_integer;
+ }
+
+ if (librad_debug) fflush(stdout);
+
+ return 0;
+}
+
+
+static int attr_cmp(const void *one, const void *two)
+{
+ const VALUE_PAIR * const *a = one;
+ const VALUE_PAIR * const *b = two;
+
+ /*
+ * DHCP-Message-Type is first, for simplicity.
+ */
+ if (((*a)->attribute == DHCP2ATTR(53)) &&
+ (*b)->attribute != DHCP2ATTR(53)) return -1;
+
+ /*
+ * Relay-Agent is last
+ */
+ if (((*a)->attribute == DHCP2ATTR(82)) &&
+ (*b)->attribute != DHCP2ATTR(82)) return +1;
+
+ return ((*a)->attribute - (*b)->attribute);
+}
+
+
+static size_t fr_dhcp_vp2attr(VALUE_PAIR *vp, uint8_t *p, size_t room)
+{
+ size_t length;
+ uint32_t lvalue;
+
+ /*
+ * FIXME: Check room!
+ */
+ room = room; /* -Wunused */
+
+ /*
+ * Search for all attributes of the same
+ * type, and pack them into the same
+ * attribute.
+ */
+ switch (vp->type) {
+ case PW_TYPE_BYTE:
+ length = 1;
+ *p = vp->vp_integer & 0xff;
+ break;
+
+ case PW_TYPE_SHORT:
+ length = 2;
+ p[0] = (vp->vp_integer >> 8) & 0xff;
+ p[1] = vp->vp_integer & 0xff;
+ break;
+
+ case PW_TYPE_INTEGER:
+ length = 4;
+ lvalue = htonl(vp->vp_integer);
+ memcpy(p, &lvalue, 4);
+ break;
+
+ case PW_TYPE_IPADDR:
+ length = 4;
+ memcpy(p, &vp->vp_ipaddr, 4);
+ break;
+
+ case PW_TYPE_ETHERNET:
+ length = 6;
+ memcpy(p, &vp->vp_ether, 6);
+ break;
+
+ case PW_TYPE_STRING:
+ memcpy(p, vp->vp_strvalue, vp->length);
+ length = vp->length;
+ break;
+
+ case PW_TYPE_OCTETS:
+ memcpy(p, vp->vp_octets, vp->length);
+ length = vp->length;
+ break;
+
+ default:
+ fprintf(stderr, "BAD TYPE2 %d\n", vp->type);
+ length = 0;
+ break;
+ }
+
+ return length;
+}
+
+int fr_dhcp_encode(RADIUS_PACKET *packet, RADIUS_PACKET *original)
+{
+ int i, num_vps;
+ uint8_t *p;
+ VALUE_PAIR *vp;
+ uint32_t lvalue, mms;
+ size_t dhcp_size, length;
+ dhcp_packet_t *dhcp;
+ char buffer[1024];
+
+ if (packet->data) return 0;
+
+ packet->data = malloc(MAX_PACKET_SIZE);
+ if (!packet->data) return -1;
+
+ packet->data_len = MAX_PACKET_SIZE;
+
+ if (packet->code == 0) packet->code = PW_DHCP_NAK;
+
+ if (librad_debug > 1) {
+ char type_buf[64];
+ const char *name = type_buf;
+ char src_ip_buf[256], dst_ip_buf[256];
+
+ if ((packet->code >= PW_DHCP_DISCOVER) &&
+ (packet->code <= PW_DHCP_INFORM)) {
+ name = dhcp_message_types[packet->code - PW_DHCP_OFFSET];
+ } else {
+ snprintf(type_buf, sizeof(type_buf), "%d",
+ packet->code - PW_DHCP_OFFSET);
+ }
+
+ printf("Sending %s of id %u from %s:%d to %s:%d\n",
+ name, (unsigned int) packet->id,
+ inet_ntop(packet->src_ipaddr.af,
+ &packet->src_ipaddr.ipaddr,
+ src_ip_buf, sizeof(src_ip_buf)),
+ packet->src_port,
+ inet_ntop(packet->dst_ipaddr.af,
+ &packet->dst_ipaddr.ipaddr,
+ dst_ip_buf, sizeof(dst_ip_buf)),
+ packet->dst_port);
+ fflush(stdout);
+ }
+
+ p = packet->data;
+
+ mms = DEFAULT_PACKET_SIZE; /* maximum message size */
+
+ /*
+ * Client can request a LARGER size, but not a smaller
+ * one. They also cannot request a size larger than MTU.
+ */
+ vp = pairfind(original->vps, DHCP2ATTR(57));
+ if (vp && (vp->vp_integer > mms)) {
+ mms = vp->vp_integer;
+
+ if (mms > MAX_PACKET_SIZE) mms = MAX_PACKET_SIZE;
+ }
+
+ /*
+ * RFC 3118: Authentication option.
+ */
+ vp = pairfind(packet->vps, DHCP2ATTR(90));
+ if (vp) {
+ if (vp->length < 2) {
+ memset(vp->vp_octets + vp->length, 0,
+ 2 - vp->length);
+ vp->length = 2;
+ }
+
+ if (vp->length < 3) {
+ struct timeval tv;
+
+ gettimeofday(&tv, NULL);
+ vp->vp_octets[2] = 0;
+ timeval2ntp(&tv, vp->vp_octets + 3);
+ vp->length = 3 + 8;
+ }
+
+ /*
+ * Configuration token (clear-text token)
+ */
+ if (vp->vp_octets[0] == 0) {
+ VALUE_PAIR *pass;
+ vp->vp_octets[1] = 0;
+
+ pass = pairfind(packet->vps, PW_CLEARTEXT_PASSWORD);
+ if (pass) {
+ length = pass->length;
+ if ((length + 11) > sizeof(vp->vp_octets)) {
+ length -= ((length + 11) - sizeof(vp->vp_octets));
+ }
+ memcpy(vp->vp_octets + 11, pass->vp_strvalue,
+ length);
+ vp->length = length + 11;
+ } else {
+ vp->length = 11 + 8;
+ memset(vp->vp_octets + 11, 8, 0);
+ vp->length = 11 + 8;
+ }
+ } else { /* we don't support this type! */
+ fprintf(stderr, "DHCP-Authentication %d unsupported\n",
+ vp->vp_octets[0]);
+ }
+ }
+
+ if (!original) {
+ *p++ = 1; /* client message */
+ } else {
+ *p++ = 2; /* server message */
+ }
+ *p++ = 1; /* hardware type = ethernet */
+ *p++ = original->data[2];
+ *p++ = 0; /* hops */
+
+ if (!original) { /* Xid */
+ lvalue = fr_rand();
+ memcpy(p, &lvalue, 4);
+ } else {
+ memcpy(p, original->data + 4, 4);
+ }
+ p += 4;
+
+ memset(p, 0, 2); /* secs are zero */
+ p += 2;
+
+ memcpy(p, original->data + 10, 6); /* copy flags && ciaddr */
+ p += 6;
+
+ /*
+ * Set client IP address.
+ */
+ vp = pairfind(packet->vps, DHCP2ATTR(264)); /* Your IP address */
+ if (vp) {
+ lvalue = vp->vp_ipaddr;
+ } else {
+ lvalue = htonl(INADDR_ANY);
+ }
+ memcpy(p, &lvalue, 4); /* your IP address */
+ p += 4;
+
+ memset(p, 0, 4); /* siaddr is zero */
+ p += 4;
+
+ memset(p, 0, 4); /* gateway address is zero */
+ p += 4;
+
+ /*
+ * FIXME: allow it to send client packets.
+ */
+ if (!original) {
+ librad_log("Need original to send response!");
+ return -1;
+ }
+
+ memcpy(p, original->data + 28, DHCP_CHADDR_LEN);
+ p += DHCP_CHADDR_LEN;
+
+ memset(p, 0, 192); /* bootp legacy */
+ p += 192;
+
+ lvalue = htonl(DHCP_OPTION_MAGIC_NUMBER); /* DHCP magic number */
+ memcpy(p, &lvalue, 4);
+ p += 4;
+
+ /*
+ * Print the header.
+ */
+ if (librad_debug > 1) {
+ uint8_t *pp = p;
+
+ p = packet->data;
+
+ for (i = 0; i < 14; i++) {
+ vp = pairmake(dhcp_header_names[i], NULL, T_OP_EQ);
+ if (!vp) {
+ fprintf(stderr, "Parse error %s\n", librad_errstr);
+ return -1;
+ }
+
+ switch (vp->type) {
+ case PW_TYPE_BYTE:
+ vp->vp_integer = p[0];
+ vp->length = 1;
+ break;
+
+ case PW_TYPE_SHORT:
+ vp->vp_integer = (p[0] << 8) | p[1];
+ vp->length = 2;
+ break;
+
+ case PW_TYPE_INTEGER:
+ memcpy(&vp->vp_integer, p, 4);
+ vp->vp_integer = ntohl(vp->vp_integer);
+ vp->length = 4;
+ break;
+
+ case PW_TYPE_IPADDR:
+ memcpy(&vp->vp_ipaddr, p, 4);
+ vp->length = 4;
+ break;
+
+ case PW_TYPE_STRING:
+ memcpy(vp->vp_strvalue, p, dhcp_header_sizes[i]);
+ vp->vp_strvalue[dhcp_header_sizes[i]] = '\0';
+ vp->length = strlen(vp->vp_strvalue);
+ break;
+
+ case PW_TYPE_OCTETS: /* only for Client HW Address */
+ memcpy(vp->vp_octets, p, packet->data[2]);
+ vp->length = packet->data[2];
+ break;
+
+ default:
+ fprintf(stderr, "Internal sanity check failed %d %d\n", vp->type, __LINE__);
+ pairfree(&vp);
+ break;
+ }
+
+ p += dhcp_header_sizes[i];
+
+ vp_prints(buffer, sizeof(buffer), vp);
+ fprintf(stderr, "\t%s\n", buffer);
+ pairfree(&vp);
+ }
+
+ /*
+ * Jump over DHCP magic number, response, etc.
+ */
+ p = pp;
+ }
+
+ vp = pairfind(packet->vps, DHCP2ATTR(53));
+ if (vp && (vp->vp_integer != (packet->code - PW_DHCP_OFFSET))) {
+ fprintf(stderr, "Message-Type doesn't match! %d %d\n",
+ packet->code, vp->vp_integer);
+ }
+ pairdelete(&packet->vps, DHCP2ATTR(0x35));
+
+ /*
+ * Before packing the attributes, re-order them so that
+ * the array ones are all contiguous. This simplifies
+ * the later code.
+ */
+ num_vps = 0;
+ for (vp = packet->vps; vp != NULL; vp = vp->next) {
+ num_vps++;
+ }
+ if (num_vps > 1) {
+ VALUE_PAIR **array, **last;
+
+ array = malloc(num_vps * sizeof(VALUE_PAIR *));
+
+ i = 0;
+ for (vp = packet->vps; vp != NULL; vp = vp->next) {
+ array[i++] = vp;
+ }
+
+ /*
+ * Sort the attributes.
+ */
+ qsort(array, (size_t) num_vps, sizeof(VALUE_PAIR *),
+ attr_cmp);
+
+ last = &packet->vps;
+ for (i = 0; i < num_vps; i++) {
+ *last = array[i];
+ array[i]->next = NULL;
+ last = &(array[i]->next);
+ }
+ free(array);
+ }
+
+ p[0] = 0x35; /* DHCP-Message-Type */
+ p[1] = 1;
+ p[2] = packet->code - PW_DHCP_OFFSET;
+ p += 3;
+
+ /*
+ * Pack in the attributes.
+ */
+ vp = packet->vps;
+ while (vp) {
+ int num_entries = 1;
+
+ VALUE_PAIR *same;
+ uint8_t *plength, *pattr;
+
+ if (!IS_DHCP_ATTR(vp)) goto next;
+ if (((vp->attribute & 0xffff) > 255) &&
+ (DHCP_BASE_ATTR(vp->attribute) != PW_DHCP_OPTION_82)) goto next;
+
+ length = vp->length;
+
+ for (same = vp->next; same != NULL; same = same->next) {
+ if (same->attribute != vp->attribute) break;
+ num_entries++;
+ }
+
+ /*
+ * For client-identifier
+ */
+ if ((vp->type == PW_TYPE_ETHERNET) &&
+ (vp->length == 6) &&
+ (num_entries == 1)) {
+ vp->type = PW_TYPE_OCTETS;
+ memmove(vp->vp_octets + 1, vp->vp_octets, 6);
+ vp->vp_octets[0] = 1;
+ }
+
+ pattr = p;
+ *(p++) = vp->attribute & 0xff;
+ plength = p;
+ *(p++) = 0; /* header isn't included in attr length */
+
+ if (DHCP_BASE_ATTR(vp->attribute) == PW_DHCP_OPTION_82) {
+ *(p++) = DHCP_UNPACK_OPTION1(vp->attribute);
+ *(p++) = 0;
+ *plength = 2;
+ }
+
+ for (i = 0; i < num_entries; i++) {
+ if (librad_debug > 1) {
+ vp_prints(buffer, sizeof(buffer), vp);
+ fprintf(stderr, "\t%s\n", buffer);
+ }
+
+ length = fr_dhcp_vp2attr(vp, p, 0);
+
+ /*
+ * This will never happen due to FreeRADIUS
+ * limitations: sizeof(vp->vp_octets) < 255
+ */
+ if (length > 255) {
+ fprintf(stderr, "WARNING Ignoring too long attribute %s!\n", vp->name);
+ break;
+ }
+
+ /*
+ * More than one attribute of the same type
+ * in a row: they are packed together
+ * into the same TLV. If we overflow,
+ * go bananas!
+ */
+ if ((*plength + length) > 255) {
+ fprintf(stderr, "WARNING Ignoring too long attribute %s!\n", vp->name);
+ break;
+ }
+
+ *plength += length;
+ p += length;
+
+ if (vp->next &&
+ (vp->next->attribute == vp->attribute))
+ vp = vp->next;
+ } /* loop over num_entries */
+
+ if (DHCP_BASE_ATTR(vp->attribute) == PW_DHCP_OPTION_82) {
+ plength[2] = plength[0] - 2;
+ }
+
+ next:
+ vp = vp->next;
+ }
+
+ p[0] = 0xff; /* end of option option */
+ p[1] = 0x00;
+ p += 2;
+ dhcp_size = p - packet->data;
+
+ /*
+ * FIXME: if (dhcp_size > mms),
+ * then we put the extra options into the "sname" and "file"
+ * fields, AND set the "end option option" in the "options"
+ * field. We also set the "overload option",
+ * and put options into the "file" field, followed by
+ * the "sname" field. Where each option is completely
+ * enclosed in the "file" and/or "sname" field, AND
+ * followed by the "end of option", and MUST be followed
+ * by padding option.
+ *
+ * Yuck. That sucks...
+ */
+ packet->data_len = dhcp_size;
+
+ packet->dst_ipaddr.af = AF_INET;
+ packet->src_ipaddr.af = AF_INET;
+
+ packet->dst_port = original->src_port;
+ packet->src_port = original->dst_port;
+
+ /*
+ * Note that for DHCP, we NEVER send the response to the
+ * source IP address of the request. It may have
+ * traversed multiple relays, and we need to send the request
+ * to the relay closest to the client.
+ *
+ * if giaddr, send to giaddr.
+ * if NAK, send broadcast packet
+ * if ciaddr, unicast to ciaddr
+ * if flags & 0x8000, broadcast (client request)
+ * if sent from 0.0.0.0, broadcast response
+ * unicast to client yiaddr
+ */
+
+ /*
+ * FIXME: alignment issues. We likely don't want to
+ * de-reference the packet structure directly..
+ */
+ dhcp = (dhcp_packet_t *) original->data;
+
+ if (dhcp->giaddr != htonl(INADDR_ANY)) {
+ packet->dst_ipaddr.ipaddr.ip4addr.s_addr = dhcp->giaddr;
+
+ } else if (packet->code == PW_DHCP_NAK) {
+ packet->dst_ipaddr.ipaddr.ip4addr.s_addr = htonl(INADDR_BROADCAST);
+
+ } else if (dhcp->ciaddr != htonl(INADDR_ANY)) {
+ packet->dst_ipaddr.ipaddr.ip4addr.s_addr = dhcp->ciaddr;
+
+ } else if ((dhcp->flags & 0x8000) != 0) {
+ packet->dst_ipaddr.ipaddr.ip4addr.s_addr = htonl(INADDR_BROADCAST);
+
+ } else if (packet->dst_ipaddr.ipaddr.ip4addr.s_addr == htonl(INADDR_ANY)) {
+ packet->dst_ipaddr.ipaddr.ip4addr.s_addr = htonl(INADDR_BROADCAST);
+
+ } else {
+ packet->dst_ipaddr.ipaddr.ip4addr.s_addr = dhcp->yiaddr;
+ }
+
+ /*
+ * FIXME: This may set it to broadcast, which we don't
+ * want. Instead, set it to the real address of the
+ * socket.
+ */
+ packet->src_ipaddr = original->dst_ipaddr;
+
+ packet->sockfd = original->sockfd;
+
+ if (packet->data_len < DEFAULT_PACKET_SIZE) {
+ memset(packet->data + packet->data_len, 0,
+ DEFAULT_PACKET_SIZE - packet->data_len);
+ packet->data_len = DEFAULT_PACKET_SIZE;
+ }
+
+ if ((librad_debug > 2) && fr_log_fp) {
+ for (i = 0; i < packet->data_len; i++) {
+ if ((i & 0x0f) == 0x00) fprintf(fr_log_fp, "%d: ", i);
+ fprintf(fr_log_fp, "%02x ", packet->data[i]);
+ if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
+ }
+ fprintf(fr_log_fp, "\n");
+ }
+
+ return 0;
+}
+#endif /* WITH_DHCP */
projects / freeradius.git / commitdiff