]> git.ipfire.org Git - thirdparty/systemd.git/blobdiff - src/libsystemd-network/dhcp-packet.c
Add SPDX license identifiers to source files under the LGPL
[thirdparty/systemd.git] / src / libsystemd-network / dhcp-packet.c
index 102ed096aff666be3668813973587ab725f5efbc..1c4ab5d52fcf0796d535db092f19d6ef70039877 100644 (file)
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
 /***
   This file is part of systemd.
 
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
-#include <stdlib.h>
 #include <errno.h>
-#include <string.h>
-#include <stdio.h>
 #include <net/ethernet.h>
 #include <net/if_arp.h>
-#include <sys/param.h>
-
-#include "util.h"
-#include "list.h"
+#include <string.h>
 
-#include "dhcp-protocol.h"
-#include "dhcp-lease-internal.h"
 #include "dhcp-internal.h"
-#include "sd-dhcp-lease.h"
-#include "sd-dhcp-client.h"
+#include "dhcp-protocol.h"
 
 #define DHCP_CLIENT_MIN_OPTIONS_SIZE            312
 
 int dhcp_message_init(DHCPMessage *message, uint8_t op, uint32_t xid,
-                      uint8_t type, uint8_t **opt, size_t *optlen) {
-        int err;
+                      uint8_t type, uint16_t arp_type, size_t optlen,
+                      size_t *optoffset) {
+        size_t offset = 0;
+        int r;
 
-        assert(op == BOOTREQUEST || op == BOOTREPLY);
+        assert(IN_SET(op, BOOTREQUEST, BOOTREPLY));
+        assert(IN_SET(arp_type, ARPHRD_ETHER, ARPHRD_INFINIBAND));
 
         message->op = op;
-        message->htype = ARPHRD_ETHER;
-        message->hlen = ETHER_ADDR_LEN;
+        message->htype = arp_type;
+        message->hlen = (arp_type == ARPHRD_ETHER) ? ETHER_ADDR_LEN : 0;
         message->xid = htobe32(xid);
         message->magic = htobe32(DHCP_MAGIC_COOKIE);
 
-        *opt = (uint8_t *)(message + 1);
+        r = dhcp_option_append(message, optlen, &offset, 0,
+                               SD_DHCP_OPTION_MESSAGE_TYPE, 1, &type);
+        if (r < 0)
+                return r;
 
-        err = dhcp_option_append(opt, optlen, DHCP_OPTION_MESSAGE_TYPE, 1,
-                                 &type);
-        if (err < 0)
-                return err;
+        *optoffset = offset;
 
         return 0;
 }
 
-uint16_t dhcp_packet_checksum(void *buf, int len) {
-        uint32_t sum;
-        uint16_t *check;
-        int i;
-        uint8_t *odd;
+uint16_t dhcp_packet_checksum(uint8_t *buf, size_t len) {
+        uint64_t *buf_64 = (uint64_t*)buf;
+        uint64_t *end_64 = buf_64 + (len / sizeof(uint64_t));
+        uint64_t sum = 0;
 
-        sum = 0;
-        check = buf;
+        /* See RFC1071 */
 
-        for (i = 0; i < len / 2 ; i++)
-                sum += check[i];
+        while (buf_64 < end_64) {
+                sum += *buf_64;
+                if (sum < *buf_64)
+                        /* wrap around in one's complement */
+                        sum++;
 
-        if (len & 0x01) {
-                odd = buf;
-                sum += odd[len - 1];
+                buf_64++;
+        }
+
+        if (len % sizeof(uint64_t)) {
+                /* If the buffer is not aligned to 64-bit, we need
+                   to zero-pad the last few bytes and add them in */
+                uint64_t buf_tail = 0;
+
+                memcpy(&buf_tail, buf_64, len % sizeof(uint64_t));
+
+                sum += buf_tail;
+                if (sum < buf_tail)
+                        /* wrap around */
+                        sum++;
         }
 
         while (sum >> 16)
@@ -89,6 +96,8 @@ void dhcp_packet_append_ip_headers(DHCPPacket *packet, be32_t source_addr,
         packet->ip.ihl = DHCP_IP_SIZE / 4;
         packet->ip.tot_len = htobe16(len);
 
+        packet->ip.tos = IPTOS_CLASS_CS6;
+
         packet->ip.protocol = IPPROTO_UDP;
         packet->ip.saddr = source_addr;
         packet->ip.daddr = destination_addr;
@@ -99,14 +108,14 @@ void dhcp_packet_append_ip_headers(DHCPPacket *packet, be32_t source_addr,
         packet->udp.len = htobe16(len - DHCP_IP_SIZE);
 
         packet->ip.check = packet->udp.len;
-        packet->udp.check = dhcp_packet_checksum(&packet->ip.ttl, len - 8);
+        packet->udp.check = dhcp_packet_checksum((uint8_t*)&packet->ip.ttl, len - 8);
 
         packet->ip.ttl = IPDEFTTL;
         packet->ip.check = 0;
-        packet->ip.check = dhcp_packet_checksum(&packet->ip, DHCP_IP_SIZE);
+        packet->ip.check = dhcp_packet_checksum((uint8_t*)&packet->ip, DHCP_IP_SIZE);
 }
 
-int dhcp_packet_verify_headers(DHCPPacket *packet, size_t len, bool checksum) {
+int dhcp_packet_verify_headers(DHCPPacket *packet, size_t len, bool checksum, uint16_t port) {
         size_t hdrlen;
 
         assert(packet);
@@ -114,48 +123,48 @@ int dhcp_packet_verify_headers(DHCPPacket *packet, size_t len, bool checksum) {
         /* IP */
 
         if (packet->ip.version != IPVERSION) {
-                log_dhcp_client(client, "ignoring packet: not IPv4");
+                log_debug("ignoring packet: not IPv4");
                 return -EINVAL;
         }
 
         if (packet->ip.ihl < 5) {
-                log_dhcp_client(client, "ignoring packet: IPv4 IHL (%u words) invalid",
-                                packet->ip.ihl);
+                log_debug("ignoring packet: IPv4 IHL (%u words) invalid",
+                          packet->ip.ihl);
                 return -EINVAL;
         }
 
         hdrlen = packet->ip.ihl * 4;
         if (hdrlen < 20) {
-                log_dhcp_client(client, "ignoring packet: IPv4 IHL (%zu bytes) "
-                                "smaller than minimum (20 bytes)", hdrlen);
+                log_debug("ignoring packet: IPv4 IHL (%zu bytes) "
+                          "smaller than minimum (20 bytes)", hdrlen);
                 return -EINVAL;
         }
 
         if (len < hdrlen) {
-                log_dhcp_client(client, "ignoring packet: packet (%zu bytes) "
-                                "smaller than expected (%zu) by IP header", len,
-                                hdrlen);
+                log_debug("ignoring packet: packet (%zu bytes) "
+                          "smaller than expected (%zu) by IP header", len,
+                          hdrlen);
                 return -EINVAL;
         }
 
         /* UDP */
 
         if (packet->ip.protocol != IPPROTO_UDP) {
-                log_dhcp_client(client, "ignoring packet: not UDP");
+                log_debug("ignoring packet: not UDP");
                 return -EINVAL;
         }
 
         if (len < hdrlen + be16toh(packet->udp.len)) {
-                log_dhcp_client(client, "ignoring packet: packet (%zu bytes) "
-                                "smaller than expected (%zu) by UDP header", len,
-                                hdrlen + be16toh(packet->udp.len));
+                log_debug("ignoring packet: packet (%zu bytes) "
+                          "smaller than expected (%zu) by UDP header", len,
+                          hdrlen + be16toh(packet->udp.len));
                 return -EINVAL;
         }
 
-        if (be16toh(packet->udp.dest) != DHCP_PORT_CLIENT) {
-                log_dhcp_client(client, "ignoring packet: to port %u, which "
-                                "is not the DHCP client port (%u)",
-                                be16toh(packet->udp.dest), DHCP_PORT_CLIENT);
+        if (be16toh(packet->udp.dest) != port) {
+                log_debug("ignoring packet: to port %u, which "
+                          "is not the DHCP client port (%u)",
+                          be16toh(packet->udp.dest), port);
                 return -EINVAL;
         }
 
@@ -163,8 +172,8 @@ int dhcp_packet_verify_headers(DHCPPacket *packet, size_t len, bool checksum) {
            if all the other checks have passed
          */
 
-        if (dhcp_packet_checksum(&packet->ip, hdrlen)) {
-                log_dhcp_client(client, "ignoring packet: invalid IP checksum");
+        if (dhcp_packet_checksum((uint8_t*)&packet->ip, hdrlen)) {
+                log_debug("ignoring packet: invalid IP checksum");
                 return -EINVAL;
         }
 
@@ -172,9 +181,9 @@ int dhcp_packet_verify_headers(DHCPPacket *packet, size_t len, bool checksum) {
                 packet->ip.check = packet->udp.len;
                 packet->ip.ttl = 0;
 
-                if (dhcp_packet_checksum(&packet->ip.ttl,
+                if (dhcp_packet_checksum((uint8_t*)&packet->ip.ttl,
                                   be16toh(packet->udp.len) + 12)) {
-                        log_dhcp_client(client, "ignoring packet: invalid UDP checksum");
+                        log_debug("ignoring packet: invalid UDP checksum");
                         return -EINVAL;
                 }
         }