diff options
Diffstat (limited to 'src/libsystemd-dhcp/sd-dhcp-client.c')
| -rw-r--r-- | src/libsystemd-dhcp/sd-dhcp-client.c | 28 |
1 files changed, 23 insertions, 5 deletions
diff --git a/src/libsystemd-dhcp/sd-dhcp-client.c b/src/libsystemd-dhcp/sd-dhcp-client.c index 7f86d92fb5..54bc19511d 100644 --- a/src/libsystemd-dhcp/sd-dhcp-client.c +++ b/src/libsystemd-dhcp/sd-dhcp-client.c @@ -279,7 +279,7 @@ static int client_send_discover(sd_dhcp_client *client, uint16_t secs) { if (err < 0) return err; - dhcp_packet_append_ip_headers(discover, BOOTREQUEST, len); + dhcp_packet_append_ip_headers(discover, len); err = dhcp_network_send_raw_socket(client->fd, &client->link, discover, len); @@ -332,7 +332,7 @@ static int client_send_request(sd_dhcp_client *client, uint16_t secs) { &request->dhcp, len - DHCP_IP_UDP_SIZE); } else { - dhcp_packet_append_ip_headers(request, BOOTREQUEST, len); + dhcp_packet_append_ip_headers(request, len); err = dhcp_network_send_raw_socket(client->fd, &client->link, request, len); @@ -736,12 +736,30 @@ static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message, assert(client->event); assert(message); - if (be32toh(message->xid) != client->xid) + if (len < DHCP_MESSAGE_SIZE) { + log_dhcp_client(client, "message too small (%d bytes): " + "ignoring", len); return 0; + } + + if (message->op != BOOTREPLY) { + log_dhcp_client(client, "not a BOOTREPLY message: ignoring"); + return 0; + } + + if (be32toh(message->xid) != client->xid) { + log_dhcp_client(client, "received xid (%u) does not match " + "expected (%u): ignoring", + be32toh(message->xid), client->xid); + return 0; + } if (memcmp(&message->chaddr[0], &client->mac_addr.ether_addr_octet, - ETHER_ADDR_LEN)) + ETHER_ADDR_LEN)) { + log_dhcp_client(client, "received chaddr does not match " + "expected: ignoring"); return 0; + } switch (client->state) { case DHCP_STATE_SELECTING: @@ -869,7 +887,7 @@ static int client_receive_message_raw(sd_event_source *s, int fd, packet = (DHCPPacket *) buf; - r = dhcp_packet_verify_headers(packet, BOOTREPLY, len); + r = dhcp_packet_verify_headers(packet, len); if (r < 0) return 0; |