/* SPDX-License-Identifier: LGPL-2.1-or-later */
+#include <net/if_arp.h>
+
#include "sd-event.h"
#include "dhcp-client-internal.h"
#include "dhcp-client-send.h"
#include "dhcp-lease-internal.h" /* IWYU pragma: keep */
+#include "dhcp-message.h"
#include "dhcp-network.h"
-#include "dhcp-packet.h"
#include "fd-util.h"
-#include "iovec-util.h"
#include "iovec-wrapper.h"
+#include "ip-util.h"
#include "socket-util.h"
static int client_get_socket(sd_dhcp_client *client, int domain) {
return 0;
}
-int dhcp_client_send_raw(
+static int client_send_raw(
sd_dhcp_client *client,
- bool expect_reply,
- DHCPPacket *packet,
- size_t optoffset) {
+ sd_dhcp_message *message,
+ bool expect_reply) {
_cleanup_close_ int fd_close = -EBADF;
int r, fd;
assert(client);
- assert(packet);
+ assert(message);
fd = client_get_socket(client, AF_PACKET);
if (fd < 0) {
fd_close = fd;
}
- r = dhcp_packet_append_ip_headers(
- packet,
+ _cleanup_(iovw_done_free) struct iovec_wrapper payload = {};
+ r = dhcp_message_build(message, &payload);
+ if (r < 0)
+ return r;
+
+ struct iphdr ip;
+ struct udphdr udp;
+ r = udp_packet_build(
INADDR_ANY,
client->port,
INADDR_BROADCAST,
client->server_port,
- sizeof(DHCPPacket) + optoffset,
- client->ip_service_type);
+ client->ip_service_type,
+ &payload,
+ &ip,
+ &udp);
if (r < 0)
return r;
- r = dhcp_network_send_raw_socket(
- fd,
- &client->link,
- &(struct iovec_wrapper) {
- .iovec = &IOVEC_MAKE(packet, sizeof(DHCPPacket) + optoffset),
- .count = 1,
- });
+ _cleanup_(iovw_done) struct iovec_wrapper iovw = {};
+ r = iovw_put(&iovw, &ip, sizeof(struct iphdr));
+ if (r < 0)
+ return r;
+
+ r = iovw_put(&iovw, &udp, sizeof(struct udphdr));
+ if (r < 0)
+ return r;
+
+ r = iovw_put_iovw(&iovw, &payload);
+ if (r < 0)
+ return r;
+
+ r = dhcp_network_send_raw_socket(fd, &client->link, &iovw);
if (r < 0)
return r;
return 0;
}
-int dhcp_client_send_udp(
+static int client_send_udp(
sd_dhcp_client *client,
- bool expect_reply,
- DHCPPacket *packet,
- size_t optoffset) {
+ sd_dhcp_message *message,
+ bool expect_reply) {
_cleanup_close_ int fd_close = -EBADF;
int r, fd;
assert(client);
- assert(packet);
+ assert(message);
if (!client->lease || client->lease->address == 0)
return -EADDRNOTAVAIL;
fd_close = fd;
}
+ _cleanup_(iovw_done_free) struct iovec_wrapper payload = {};
+ r = dhcp_message_build(message, &payload);
+ if (r < 0)
+ return r;
+
r = dhcp_network_send_udp_socket(
fd,
client->lease->server_address,
client->server_port,
- &(struct iovec_wrapper) {
- .iovec = &IOVEC_MAKE(&packet->dhcp, sizeof(DHCPMessage) + optoffset),
- .count = 1,
- });
+ &payload);
if (r < 0)
return r;
TAKE_FD(fd_close);
return 0;
}
+
+static int client_new_message(sd_dhcp_client *client, uint8_t type, sd_dhcp_message **ret) {
+ int r;
+
+ assert(client);
+ assert(IN_SET(type, DHCP_DISCOVER, DHCP_REQUEST, DHCP_RELEASE, DHCP_DECLINE));
+ assert(ret);
+
+ _cleanup_(sd_dhcp_message_unrefp) sd_dhcp_message *message = NULL;
+ r = dhcp_message_new(&message);
+ if (r < 0)
+ return r;
+
+ r = dhcp_message_init_header(
+ message,
+ BOOTREQUEST,
+ client->xid,
+ client->arp_type,
+ &client->hw_addr);
+ if (r < 0)
+ return r;
+
+ /* Although 'secs' field is a SHOULD in RFC 2131, certain DHCP servers refuse to issue a DHCP lease
+ * if 'secs' is set to zero. */
+ usec_t time_now;
+ r = sd_event_now(client->event, CLOCK_BOOTTIME, &time_now);
+ if (r < 0)
+ return r;
+ assert(time_now >= client->start_time);
+
+ /* Seconds between sending first and last DISCOVER must always be strictly positive to deal with
+ * broken servers. */
+ message->header.secs = usec_to_be16_sec(usec_sub_unsigned(time_now, client->start_time) ?: 1 * USEC_PER_SEC);
+
+ /* RFC2131 section 4.1
+ * A client that cannot receive unicast IP datagrams until its protocol software has been configured
+ * with an IP address SHOULD set the BROADCAST bit in the 'flags' field to 1 in any DHCPDISCOVER or
+ * DHCPREQUEST messages that client sends. The BROADCAST bit will provide a hint to the DHCP server
+ * and BOOTP relay agent to broadcast any messages to the client on the client's subnet.
+ *
+ * Note: some interfaces needs this to be enabled, but some networks need this to be disabled as
+ * broadcasts are filtered, so this needs to be configurable. */
+ dhcp_message_set_broadcast_flag(message, client->request_broadcast || client->arp_type != ARPHRD_ETHER);
+
+ /* We append no vendor options on BOOTP mode. */
+ if (client->bootp) {
+ *ret = TAKE_PTR(message);
+ return 0;
+ }
+
+ /* DHCP Message Type (53): Mandatory. */
+ r = dhcp_message_append_option_u8(message, SD_DHCP_OPTION_MESSAGE_TYPE, type);
+ if (r < 0)
+ return r;
+
+ /* Server Identifier (54): mandatory in DHCPREQUEST on REQUESTING state. It is also mandatory when
+ * DHCPRELEASE and DHCPDECLINE. */
+ if ((type == DHCP_REQUEST && client->state == DHCP_STATE_REQUESTING) ||
+ IN_SET(type, DHCP_RELEASE, DHCP_DECLINE)) {
+ r = dhcp_message_append_option_be32(
+ message,
+ SD_DHCP_OPTION_SERVER_IDENTIFIER,
+ ASSERT_PTR(client->lease)->server_address);
+ if (r < 0)
+ return r;
+ }
+
+ /* Client Identifier (61): Not mandatory, but some DHCP servers will reject messages without client
+ * identifier option. Hence, we always set it. */
+ r = dhcp_message_append_option_client_id(message, &client->client_id);
+ if (r < 0)
+ return r;
+
+ /* Requested IP Address option (50) or ciaddr
+ *
+ * See RFC2131 section 4.3.2 (note that there is a typo in the RFC, SELECTING should be REQUESTING). */
+ be32_t addr = INADDR_ANY;
+ switch (type) {
+ case DHCP_DISCOVER:
+ /* the client may suggest values for the network address and lease time in the DHCPDISCOVER
+ * message. The client may include the ’requested IP address’ option to suggest that a
+ * particular IP address be assigned, and may include the ’IP address lease time’ option to
+ * suggest the lease time it would like.
+ *
+ * RFC7844 section 3:
+ * SHOULD NOT contain any other option (when running on anonymize mode). */
+ if (!client->anonymize)
+ addr = client->last_addr;
+ break;
+
+ case DHCP_REQUEST:
+ switch (client->state) {
+
+ case DHCP_STATE_REQUESTING:
+ /* ’ciaddr’ MUST be zero, ’requested IP address’ MUST be filled in with the
+ * yiaddr value from the chosen DHCPOFFER. */
+ addr = ASSERT_PTR(client->lease)->address;
+ break;
+
+ case DHCP_STATE_REBOOTING:
+ /* ’requested IP address’ option MUST be filled in with client’s notion of its
+ * previously assigned address. ’ciaddr’ MUST be zero. */
+ addr = client->last_addr;
+ break;
+
+ case DHCP_STATE_RENEWING:
+ case DHCP_STATE_REBINDING:
+ /* ’requested IP address’ option MUST NOT be filled in, ’ciaddr’ MUST be filled
+ * in with client’s IP address. */
+ message->header.ciaddr = ASSERT_PTR(client->lease)->address;
+ break;
+
+ default:
+ assert_not_reached();
+ }
+ break;
+
+ case DHCP_RELEASE:
+ /* The acquired address must be set in ciaddr. */
+ message->header.ciaddr = ASSERT_PTR(client->lease)->address;
+ break;
+
+ case DHCP_DECLINE:
+ /* The acquired address must be set in Requested IP Address option. */
+ addr = ASSERT_PTR(client->lease)->address;
+ break;
+
+ default:
+ assert_not_reached();
+ }
+
+ if (addr != INADDR_ANY) {
+ r = dhcp_message_append_option_be32(message, SD_DHCP_OPTION_REQUESTED_IP_ADDRESS, addr);
+ if (r < 0)
+ return r;
+ }
+
+ /* DHCPRELEASE and DHCPDECLINE MUST NOT contain any other options. */
+ if (IN_SET(type, DHCP_RELEASE, DHCP_DECLINE)) {
+ *ret = TAKE_PTR(message);
+ return 0;
+ }
+
+ /* Parameter Request List (55)
+ *
+ * RFC2131 section 3.5:
+ * in its initial DHCPDISCOVER or DHCPREQUEST message, a client may provide the server with a list of
+ * specific parameters the client is interested in. If the client includes a list of parameters in a
+ * DHCPDISCOVER message, it MUST include that list in any subsequent DHCPREQUEST messages.
+ *
+ * RFC7844 section 3:
+ * MAY contain the Parameter Request List option.
+ *
+ * RFC7844 section 3.6:
+ * The client intending to protect its privacy SHOULD only request a minimal number of options in the
+ * PRL and SHOULD also randomly shuffle the ordering of option codes in the PRL. If this random
+ * ordering cannot be implemented, the client MAY order the option codes in the PRL by option code
+ * number (lowest to highest).
+ *
+ * NOTE: using PRL options that Windows 10 RFC7844 implementation uses. */
+ if (client->anonymize) {
+ static const uint8_t default_req_opts_anonymize[] = {
+ SD_DHCP_OPTION_SUBNET_MASK, /* 1 */
+ SD_DHCP_OPTION_ROUTER, /* 3 */
+ SD_DHCP_OPTION_DOMAIN_NAME_SERVER, /* 6 */
+ SD_DHCP_OPTION_DOMAIN_NAME, /* 15 */
+ SD_DHCP_OPTION_ROUTER_DISCOVERY, /* 31 */
+ SD_DHCP_OPTION_STATIC_ROUTE, /* 33 */
+ SD_DHCP_OPTION_VENDOR_SPECIFIC_INFORMATION, /* 43 */
+ SD_DHCP_OPTION_NETBIOS_NAME_SERVER, /* 44 */
+ SD_DHCP_OPTION_NETBIOS_NODE_TYPE, /* 46 */
+ SD_DHCP_OPTION_NETBIOS_SCOPE, /* 47 */
+ SD_DHCP_OPTION_CLASSLESS_STATIC_ROUTE, /* 121 */
+ SD_DHCP_OPTION_PRIVATE_CLASSLESS_STATIC_ROUTE, /* 249 */
+ SD_DHCP_OPTION_PRIVATE_PROXY_AUTODISCOVERY, /* 252 */
+ };
+
+ r = dhcp_message_append_option(
+ message,
+ SD_DHCP_OPTION_PARAMETER_REQUEST_LIST,
+ ELEMENTSOF(default_req_opts_anonymize),
+ default_req_opts_anonymize);
+ if (r < 0)
+ return r;
+
+ /* RFC7844 section 3:
+ * SHOULD NOT contain any other option (when running on anonymize mode). */
+ *ret = TAKE_PTR(message);
+ return 0;
+ }
+
+ /* When not on anonymized mode, use the default + user requested options. */
+ r = dhcp_message_append_option_parameter_request_list(message, client->req_opts);
+ if (r < 0)
+ return r;
+
+ /* Maximum Message Size (57)
+ *
+ * RFC2131 section 3.5:
+ * The client SHOULD include the ’maximum DHCP message size’ option to let the server know how
+ * large the server may make its DHCP messages.
+ *
+ * Note (from ConnMan): Some DHCP servers will send bigger DHCP packets than the defined default size
+ * unless the Maximum Message Size option is explicitly set.
+ *
+ * RFC3442 "Requirements to Avoid Sizing Constraints":
+ * Because a full routing table can be quite large, the standard 576 octet maximum size for a DHCP
+ * message may be too short to contain some legitimate Classless Static Route options. Because of
+ * this, clients implementing the Classless Static Route option SHOULD send a Maximum DHCP Message
+ * Size [4] option if the DHCP client's TCP/IP stack is capable of receiving larger IP datagrams.
+ * In this case, the client SHOULD set the value of this option to at least the MTU of the interface
+ * that the client is configuring. The client MAY set the value of this option higher, up to the size
+ * of the largest UDP packet it is prepared to accept. (Note that the value specified in the Maximum
+ * DHCP Message Size option is the total maximum packet size, including IP and UDP headers.) */
+ r = dhcp_message_append_option_u16(
+ message,
+ SD_DHCP_OPTION_MAXIMUM_MESSAGE_SIZE,
+ CLAMP(client->mtu, (uint32_t) IPV4_MIN_REASSEMBLY_SIZE, (uint32_t) UINT16_MAX));
+ if (r < 0)
+ return r;
+
+ /* Hostname (12) or FQDN (81)
+ *
+ * Note, it is unclear from RFC 2131 if client should send hostname in DHCPDISCOVER but dhclient does
+ * and so we do as well. */
+ r = dhcp_message_append_option_hostname(
+ message,
+ DHCP_FQDN_FLAG_S, /* Request server to perform A RR DNS updates */
+ /* is_client= */ true,
+ client->hostname);
+ if (r < 0)
+ return r;
+
+ /* Vendor Specific (43) */
+ r = dhcp_message_append_option_sub_tlv(
+ message,
+ SD_DHCP_OPTION_VENDOR_SPECIFIC_INFORMATION,
+ client->vendor_options);
+ if (r < 0)
+ return r;
+
+ /* Vendor Class Identifier (60) */
+ r = dhcp_message_append_option_string(
+ message,
+ SD_DHCP_OPTION_VENDOR_CLASS_IDENTIFIER,
+ client->vendor_class_identifier);
+ if (r < 0)
+ return r;
+
+ /* User Class (77) */
+ r = dhcp_message_append_option_length_prefixed_data(
+ message,
+ SD_DHCP_OPTION_USER_CLASS,
+ /* length_size= */ 1,
+ &client->user_class);
+ if (r < 0)
+ return r;
+
+ /* Rapid Commit (80): only for DHCPDISCOVER */
+ if (client->rapid_commit && type == DHCP_DISCOVER) {
+ r = dhcp_message_append_option_flag(message, SD_DHCP_OPTION_RAPID_COMMIT);
+ if (r < 0)
+ return r;
+ }
+
+ /* MUD URL (161) */
+ r = dhcp_message_append_option_string(message, SD_DHCP_OPTION_MUD_URL, client->mudurl);
+ if (r < 0)
+ return r;
+
+ r = dhcp_message_append_option_tlv(message, client->extra_options);
+ if (r < 0)
+ return r;
+
+ *ret = TAKE_PTR(message);
+ return 0;
+}
+
+int dhcp_client_send_message(sd_dhcp_client *client, uint8_t type) {
+ int r;
+
+ assert(client);
+
+ _cleanup_(sd_dhcp_message_unrefp) sd_dhcp_message *message = NULL;
+ r = client_new_message(client, type, &message);
+ if (r < 0)
+ return r;
+
+ switch (type) {
+ case DHCP_DISCOVER:
+ r = client_send_raw(client, message, /* expect_reply= */ true);
+ break;
+ case DHCP_REQUEST:
+ if (client->state == DHCP_STATE_RENEWING)
+ r = client_send_udp(client, message, /* expect_reply= */ true);
+ else
+ r = client_send_raw(client, message, /* expect_reply= */ true);
+ break;
+ case DHCP_RELEASE:
+ r = client_send_udp(client, message, /* expect_reply= */ false);
+ break;
+ case DHCP_DECLINE:
+ r = client_send_raw(client, message, /* expect_reply= */ false);
+ break;
+ default:
+ r = -EINVAL;
+ }
+ if (r < 0)
+ return r;
+
+ if (client->bootp)
+ log_dhcp_client(client, "BOOTREQUEST");
+ else if (type == DHCP_REQUEST)
+ log_dhcp_client(client, "%s (%s)",
+ dhcp_message_type_to_string(type),
+ dhcp_state_to_string(client->state));
+ else
+ log_dhcp_client(client, "%s", dhcp_message_type_to_string(type));
+ return 0;
+}
#include "network-common.h"
#include "random-util.h"
#include "set.h"
-#include "sort-util.h"
#include "string-table.h"
#include "string-util.h"
#include "time-util.h"
return MAX(usec_sub_unsigned(expire, now_usec) / 2, 60 * USEC_PER_SEC);
}
-static int cmp_uint8(const uint8_t *a, const uint8_t *b) {
- assert(a);
- assert(b);
-
- return CMP(*a, *b);
-}
-
-static int client_message_init(
- sd_dhcp_client *client,
- uint8_t type,
- DHCPPacket **ret_packet,
- size_t *ret_optlen,
- size_t *ret_optoffset) {
-
- _cleanup_free_ DHCPPacket *packet = NULL;
- size_t optlen, optoffset, size;
- usec_t time_now;
- uint16_t secs;
- int r;
-
- assert(client);
- assert(IN_SET(type, DHCP_DISCOVER, DHCP_REQUEST, DHCP_RELEASE, DHCP_DECLINE));
- assert(ret_packet);
- assert(ret_optlen);
- assert(ret_optoffset);
-
- optlen = DHCP_MIN_OPTIONS_SIZE;
- size = sizeof(DHCPPacket) + optlen;
-
- packet = malloc0(size);
- if (!packet)
- return -ENOMEM;
- if (client->bootp) {
- /* BOOTP supports options, but only DHCP_OPTION_END is used. The rest of the 64-byte buffer
- * is set to zero, per RFC1542. Allow for this by initialaizing optoffset to 0. */
- optoffset = 0;
- r = bootp_message_init(
- &packet->dhcp, BOOTREQUEST, client->xid, client->arp_type,
- client->hw_addr.length, client->hw_addr.bytes);
- } else
- r = dhcp_message_init(
- &packet->dhcp, BOOTREQUEST, client->xid, client->arp_type,
- client->hw_addr.length, client->hw_addr.bytes,
- type, optlen, &optoffset);
- if (r < 0)
- return r;
-
- /* Although 'secs' field is a SHOULD in RFC 2131, certain DHCP servers
- refuse to issue an DHCP lease if 'secs' is set to zero */
- r = sd_event_now(client->event, CLOCK_BOOTTIME, &time_now);
- if (r < 0)
- return r;
- assert(time_now >= client->start_time);
-
- /* seconds between sending first and last DISCOVER
- * must always be strictly positive to deal with broken servers */
- secs = ((time_now - client->start_time) / USEC_PER_SEC) ?: 1;
- packet->dhcp.secs = htobe16(secs);
-
- /* RFC2131 section 4.1
- A client that cannot receive unicast IP datagrams until its protocol
- software has been configured with an IP address SHOULD set the
- BROADCAST bit in the 'flags' field to 1 in any DHCPDISCOVER or
- DHCPREQUEST messages that client sends. The BROADCAST bit will
- provide a hint to the DHCP server and BOOTP relay agent to broadcast
- any messages to the client on the client's subnet.
-
- Note: some interfaces needs this to be enabled, but some networks
- needs this to be disabled as broadcasts are filteretd, so this
- needs to be configurable */
- if (client->request_broadcast || client->arp_type != ARPHRD_ETHER)
- packet->dhcp.flags = htobe16(0x8000);
-
- if (client->bootp) {
- *ret_optlen = optlen;
- *ret_optoffset = optoffset;
- *ret_packet = TAKE_PTR(packet);
- return 0;
- }
-
- /* Some DHCP servers will refuse to issue an DHCP lease if the Client
- Identifier option is not set */
- r = dhcp_option_append(&packet->dhcp, optlen, &optoffset, 0,
- SD_DHCP_OPTION_CLIENT_IDENTIFIER,
- client->client_id.size,
- client->client_id.raw);
- if (r < 0)
- return r;
-
- /* RFC2131 section 3.5:
- in its initial DHCPDISCOVER or DHCPREQUEST message, a
- client may provide the server with a list of specific
- parameters the client is interested in. If the client
- includes a list of parameters in a DHCPDISCOVER message,
- it MUST include that list in any subsequent DHCPREQUEST
- messages.
- */
-
- /* RFC7844 section 3:
- MAY contain the Parameter Request List option. */
- /* NOTE: in case that there would be an option to do not send
- * any PRL at all, the size should be checked before sending */
- if (!set_isempty(client->req_opts) && IN_SET(type, DHCP_DISCOVER, DHCP_REQUEST)) {
- _cleanup_free_ uint8_t *opts = NULL;
- size_t n_opts, i = 0;
- void *val;
-
- n_opts = set_size(client->req_opts);
- opts = new(uint8_t, n_opts);
- if (!opts)
- return -ENOMEM;
-
- SET_FOREACH(val, client->req_opts)
- opts[i++] = PTR_TO_UINT8(val);
- assert(i == n_opts);
-
- /* For anonymizing the request, let's sort the options. */
- typesafe_qsort(opts, n_opts, cmp_uint8);
-
- r = dhcp_option_append(&packet->dhcp, optlen, &optoffset, 0,
- SD_DHCP_OPTION_PARAMETER_REQUEST_LIST,
- n_opts, opts);
- if (r < 0)
- return r;
- }
-
- /* RFC2131 section 3.5:
- The client SHOULD include the ’maximum DHCP message size’ option to
- let the server know how large the server may make its DHCP messages.
-
- Note (from ConnMan): Some DHCP servers will send bigger DHCP packets
- than the defined default size unless the Maximum Message Size option
- is explicitly set
-
- RFC3442 "Requirements to Avoid Sizing Constraints":
- Because a full routing table can be quite large, the standard 576
- octet maximum size for a DHCP message may be too short to contain
- some legitimate Classless Static Route options. Because of this,
- clients implementing the Classless Static Route option SHOULD send a
- Maximum DHCP Message Size [4] option if the DHCP client's TCP/IP
- stack is capable of receiving larger IP datagrams. In this case, the
- client SHOULD set the value of this option to at least the MTU of the
- interface that the client is configuring. The client MAY set the
- value of this option higher, up to the size of the largest UDP packet
- it is prepared to accept. (Note that the value specified in the
- Maximum DHCP Message Size option is the total maximum packet size,
- including IP and UDP headers.)
- */
- /* RFC7844 section 3:
- SHOULD NOT contain any other option. */
- if (!client->anonymize && IN_SET(type, DHCP_DISCOVER, DHCP_REQUEST)) {
- be16_t max_size = htobe16(MIN(client->mtu - DHCP_IP_UDP_SIZE, (uint32_t) UINT16_MAX));
- r = dhcp_option_append(&packet->dhcp, optlen, &optoffset, 0,
- SD_DHCP_OPTION_MAXIMUM_MESSAGE_SIZE,
- 2, &max_size);
- if (r < 0)
- return r;
- }
-
- *ret_optlen = optlen;
- *ret_optoffset = optoffset;
- *ret_packet = TAKE_PTR(packet);
-
- return 0;
-}
-
-static int client_append_fqdn_option(
- DHCPMessage *message,
- size_t optlen,
- size_t *optoffset,
- const char *fqdn) {
-
- uint8_t buffer[3 + DHCP_MAX_FQDN_LENGTH];
- int r;
-
- buffer[0] = DHCP_FQDN_FLAG_S | /* Request server to perform A RR DNS updates */
- DHCP_FQDN_FLAG_E; /* Canonical wire format */
- buffer[1] = 0; /* RCODE1 (deprecated) */
- buffer[2] = 0; /* RCODE2 (deprecated) */
-
- r = dns_name_to_wire_format(fqdn, buffer + 3, sizeof(buffer) - 3, false);
- if (r > 0)
- r = dhcp_option_append(message, optlen, optoffset, 0,
- SD_DHCP_OPTION_FQDN, 3 + r, buffer);
-
- return r;
-}
-
-static int client_append_common_discover_request_options(sd_dhcp_client *client, DHCPPacket *packet, size_t *optoffset, size_t optlen) {
- int r;
-
- assert(client);
-
- if (client->hostname) {
- /* According to RFC 4702 "clients that send the Client FQDN option in
- their messages MUST NOT also send the Host Name option". Just send
- one of the two depending on the hostname type.
- */
- if (dns_name_is_single_label(client->hostname)) {
- /* it is unclear from RFC 2131 if client should send hostname in
- DHCPDISCOVER but dhclient does and so we do as well
- */
- r = dhcp_option_append(&packet->dhcp, optlen, optoffset, 0,
- SD_DHCP_OPTION_HOST_NAME,
- strlen(client->hostname), client->hostname);
- } else
- r = client_append_fqdn_option(&packet->dhcp, optlen, optoffset,
- client->hostname);
- if (r < 0)
- return r;
- }
-
- if (client->vendor_class_identifier) {
- r = dhcp_option_append(&packet->dhcp, optlen, optoffset, 0,
- SD_DHCP_OPTION_VENDOR_CLASS_IDENTIFIER,
- strlen(client->vendor_class_identifier),
- client->vendor_class_identifier);
- if (r < 0)
- return r;
- }
-
- if (client->mudurl) {
- r = dhcp_option_append(&packet->dhcp, optlen, optoffset, 0,
- SD_DHCP_OPTION_MUD_URL,
- strlen(client->mudurl),
- client->mudurl);
- if (r < 0)
- return r;
- }
-
- if (!iovw_isempty(&client->user_class)) {
- size_t sz = iovw_size(&client->user_class) + client->user_class.count;
- if (sz <= UINT8_MAX) {
- _cleanup_free_ uint8_t *buf = new(uint8_t, sz);
- if (!buf)
- return -ENOMEM;
-
- uint8_t *p = buf;
- FOREACH_ARRAY(iovec, client->user_class.iovec, client->user_class.count) {
- assert(iovec->iov_len > 0 && iovec->iov_len <= UINT8_MAX);
- *p++ = iovec->iov_len;
- p = mempcpy(p, iovec->iov_base, iovec->iov_len);
- }
-
- r = dhcp_option_append(&packet->dhcp, optlen, optoffset, 0,
- SD_DHCP_OPTION_USER_CLASS,
- sz, buf);
- if (r < 0)
- return r;
- }
- }
-
- if (client->extra_options) {
- void *key;
- struct iovec_wrapper *iovw;
- HASHMAP_FOREACH_KEY(iovw, key, client->extra_options->entries) {
- uint32_t tag = PTR_TO_UINT32(key);
-
- FOREACH_ARRAY(iov, iovw->iovec, iovw->count) {
- r = dhcp_option_append(&packet->dhcp, optlen, optoffset, 0,
- tag, iov->iov_len, iov->iov_base);
- if (r < 0)
- return r;
- }
- }
- }
-
- if (!tlv_isempty(client->vendor_options)) {
- _cleanup_(iovec_done) struct iovec iov = {};
- r = tlv_build(client->vendor_options, &iov);
- if (r < 0)
- return r;
-
- r = dhcp_option_append(
- &packet->dhcp, optlen, optoffset, 0,
- SD_DHCP_OPTION_VENDOR_SPECIFIC_INFORMATION,
- iov.iov_len, iov.iov_base);
- if (r < 0)
- return r;
- }
-
- return 0;
-}
-
-static int client_send_dhcp_discover(sd_dhcp_client *client) {
- _cleanup_free_ DHCPPacket *discover = NULL;
- size_t optoffset, optlen;
- int r;
-
- assert(client);
-
- r = client_message_init(client, DHCP_DISCOVER, &discover, &optlen, &optoffset);
- if (r < 0)
- return r;
-
- /* the client may suggest values for the network address
- and lease time in the DHCPDISCOVER message. The client may include
- the ’requested IP address’ option to suggest that a particular IP
- address be assigned, and may include the ’IP address lease time’
- option to suggest the lease time it would like.
- */
- /* RFC7844 section 3:
- SHOULD NOT contain any other option. */
- if (!client->anonymize && client->last_addr != INADDR_ANY) {
- r = dhcp_option_append(&discover->dhcp, optlen, &optoffset, 0,
- SD_DHCP_OPTION_REQUESTED_IP_ADDRESS,
- 4, &client->last_addr);
- if (r < 0)
- return r;
- }
-
- if (client->rapid_commit) {
- r = dhcp_option_append(&discover->dhcp, optlen, &optoffset, 0,
- SD_DHCP_OPTION_RAPID_COMMIT, 0, NULL);
- if (r < 0)
- return r;
- }
-
- r = client_append_common_discover_request_options(client, discover, &optoffset, optlen);
- if (r < 0)
- return r;
-
- r = dhcp_option_append(&discover->dhcp, optlen, &optoffset, 0,
- SD_DHCP_OPTION_END, 0, NULL);
- if (r < 0)
- return r;
-
- r = dhcp_client_send_raw(client, /* expect_reply= */ true, discover, optoffset);
- if (r < 0)
- return r;
-
- log_dhcp_client(client, "DISCOVER");
- return 0;
-}
-
-static int client_send_bootp_discover(sd_dhcp_client *client) {
- _cleanup_free_ DHCPPacket *discover = NULL;
- size_t optoffset, optlen;
- int r;
-
- assert(client);
-
- r = client_message_init(client, DHCP_DISCOVER, &discover, &optlen, &optoffset);
- if (r < 0)
- return r;
-
- r = dhcp_option_append(&discover->dhcp, optlen, &optoffset, 0, SD_DHCP_OPTION_END, 0, NULL);
- if (r < 0)
- return r;
-
- /* RFC1542 section 3.5:
- * if the client has no information to communicate to the server, the octet immediately following the
- * magic cookie SHOULD be set to the "End" tag (255) and the remaining octets of the 'vend' field
- * SHOULD be set to zero.
- *
- * Use this RFC, along with the fact that some BOOTP servers require a 64-byte vend field, to suggest
- * that we always zero and send 64 bytes in the options field. The first four bites are the "magic"
- * field, so this only needs to add 60 bytes. */
- if (optoffset < 60 && optlen >= 60) {
- memzero(&discover->dhcp.options[optoffset], optlen - optoffset);
- optoffset = 60;
- }
-
- r = dhcp_client_send_raw(client, /* expect_reply= */ true, discover, optoffset);
- if (r < 0)
- return r;
-
- log_dhcp_client(client, "DISCOVER");
- return 0;
-}
-
-static int client_send_discover(sd_dhcp_client *client) {
- assert(client);
- assert(client->state == DHCP_STATE_SELECTING);
-
- return client->bootp ?
- client_send_bootp_discover(client) :
- client_send_dhcp_discover(client);
-}
-
-static int client_send_request(sd_dhcp_client *client) {
- _cleanup_free_ DHCPPacket *request = NULL;
- size_t optoffset, optlen;
- int r;
-
- assert(client);
- assert(!client->bootp);
-
- r = client_message_init(client, DHCP_REQUEST, &request, &optlen, &optoffset);
- if (r < 0)
- return r;
-
- switch (client->state) {
- /* See RFC2131 section 4.3.2 (note that there is a typo in the RFC,
- SELECTING should be REQUESTING)
- */
-
- case DHCP_STATE_REQUESTING:
- /* Client inserts the address of the selected server in ’server
- identifier’, ’ciaddr’ MUST be zero, ’requested IP address’ MUST be
- filled in with the yiaddr value from the chosen DHCPOFFER.
- */
-
- r = dhcp_option_append(&request->dhcp, optlen, &optoffset, 0,
- SD_DHCP_OPTION_SERVER_IDENTIFIER,
- 4, &client->lease->server_address);
- if (r < 0)
- return r;
-
- r = dhcp_option_append(&request->dhcp, optlen, &optoffset, 0,
- SD_DHCP_OPTION_REQUESTED_IP_ADDRESS,
- 4, &client->lease->address);
- if (r < 0)
- return r;
- break;
-
- case DHCP_STATE_REBOOTING:
- /* ’server identifier’ MUST NOT be filled in, ’requested IP address’
- option MUST be filled in with client’s notion of its previously
- assigned address. ’ciaddr’ MUST be zero.
- */
- r = dhcp_option_append(&request->dhcp, optlen, &optoffset, 0,
- SD_DHCP_OPTION_REQUESTED_IP_ADDRESS,
- 4, &client->last_addr);
- if (r < 0)
- return r;
- break;
-
- case DHCP_STATE_RENEWING:
- /* ’server identifier’ MUST NOT be filled in, ’requested IP address’
- option MUST NOT be filled in, ’ciaddr’ MUST be filled in with
- client’s IP address.
- */
-
- case DHCP_STATE_REBINDING:
- /* ’server identifier’ MUST NOT be filled in, ’requested IP address’
- option MUST NOT be filled in, ’ciaddr’ MUST be filled in with
- client’s IP address.
-
- This message MUST be broadcast to the 0xffffffff IP broadcast address.
- */
- request->dhcp.ciaddr = client->lease->address;
- break;
-
- default:
- assert_not_reached();
- }
-
- r = client_append_common_discover_request_options(client, request, &optoffset, optlen);
- if (r < 0)
- return r;
-
- r = dhcp_option_append(&request->dhcp, optlen, &optoffset, 0,
- SD_DHCP_OPTION_END, 0, NULL);
- if (r < 0)
- return r;
-
- if (client->state == DHCP_STATE_RENEWING)
- r = dhcp_client_send_udp(client, /* expect_reply= */ true, request, optoffset);
- else
- r = dhcp_client_send_raw(client, /* expect_reply= */ true, request, optoffset);
- if (r < 0)
- return r;
-
- switch (client->state) {
-
- case DHCP_STATE_REQUESTING:
- log_dhcp_client(client, "REQUEST (requesting)");
- break;
-
- case DHCP_STATE_REBOOTING:
- log_dhcp_client(client, "REQUEST (rebooting)");
- break;
-
- case DHCP_STATE_RENEWING:
- log_dhcp_client(client, "REQUEST (renewing)");
- break;
-
- case DHCP_STATE_REBINDING:
- log_dhcp_client(client, "REQUEST (rebinding)");
- break;
-
- default:
- assert_not_reached();
- }
-
- return 0;
-}
-
static int client_timeout_resend(
sd_event_source *s,
uint64_t usec,
switch (client->state) {
case DHCP_STATE_SELECTING:
- r = client_send_discover(client);
+ r = dhcp_client_send_message(client, DHCP_DISCOVER);
if (r < 0 && client->discover_attempt >= client->max_discover_attempts)
goto error;
break;
case DHCP_STATE_REBOOTING:
- r = client_send_request(client);
+ r = dhcp_client_send_message(client, DHCP_REQUEST);
if (r < 0 && client->request_attempt >= MAX_REQUEST_ATTEMPTS_ON_REBOOTING)
goto restart;
break;
case DHCP_STATE_REQUESTING:
case DHCP_STATE_RENEWING:
case DHCP_STATE_REBINDING:
- r = client_send_request(client);
+ r = dhcp_client_send_message(client, DHCP_REQUEST);
if (r < 0 && client->request_attempt >= MAX_REQUEST_ATTEMPTS)
goto restart;
break;
return r;
}
-static int client_send_release_or_decline(sd_dhcp_client *client, uint8_t type) {
+int sd_dhcp_client_send_decline(sd_dhcp_client *client) {
int r;
- assert(IN_SET(type, DHCP_RELEASE, DHCP_DECLINE));
-
if (!sd_dhcp_client_is_running(client) || !client->lease || client->bootp)
- return 0; /* there is nothing to release or decline */
-
- const char *name = type == DHCP_RELEASE ? "RELEASE" : "DECLINE";
-
- _cleanup_free_ DHCPPacket *packet = NULL;
- size_t optoffset, optlen;
- r = client_message_init(client, type, &packet, &optlen, &optoffset);
- if (r < 0)
- return log_dhcp_client_errno(client, r, "Failed to initialize DHCP %s message: %m", name);
-
- /* See RFC 2131, Table 5 */
- switch (type) {
- case DHCP_RELEASE:
- /* On release, the acquired address must be set in ciaddr. */
- packet->dhcp.ciaddr = client->lease->address;
- break;
-
- case DHCP_DECLINE:
- /* On decline, the acquired address must be set in Requested IP Address option. */
- r = dhcp_option_append(&packet->dhcp, optlen, &optoffset, /* overload= */ 0,
- SD_DHCP_OPTION_REQUESTED_IP_ADDRESS,
- 4, &client->lease->address);
- if (r < 0)
- return log_dhcp_client_errno(
- client, r,
- "Failed to append Requested IP Address option to DHCP %s message: %m",
- name);
- break;
-
- default:
- assert_not_reached();
- }
-
- /* In both cases, the server identifier must be set. */
- r = dhcp_option_append(&packet->dhcp, optlen, &optoffset, /* overload= */ 0,
- SD_DHCP_OPTION_SERVER_IDENTIFIER,
- 4, &client->lease->server_address);
- if (r < 0)
- return log_dhcp_client_errno(
- client, r,
- "Failed to append Server Identifier option to DHCP %s message: %m",
- name);
+ return 0; /* there is nothing to decline */
- r = dhcp_option_append(&packet->dhcp, optlen, &optoffset, /* overload= */ 0,
- SD_DHCP_OPTION_END, /* optlen= */ 0, /* optval= */ NULL);
+ r = dhcp_client_send_message(client, DHCP_DECLINE);
if (r < 0)
- return log_dhcp_client_errno(
- client, r,
- "Failed to finalize DHCP %s message: %m",
- name);
-
- switch (type) {
- case DHCP_RELEASE:
- r = dhcp_client_send_udp(client, /* expect_reply= */ false, packet, optoffset);
- break;
- case DHCP_DECLINE:
- r = dhcp_client_send_raw(client, /* expect_reply= */ false, packet, optoffset);
- break;
- default:
- assert_not_reached();
- }
- if (r < 0)
- return log_dhcp_client_errno(
- client, r,
- "Failed to send DHCP %s message: %m",
- name);
+ return r;
- log_dhcp_client(client, "%s", name);
- return 1; /* sent */
+ /* This function is mostly called when the acquired address conflicts with another host.
+ * Restarting the daemon to acquire another address. */
+ return client_restart(client);
}
-int sd_dhcp_client_send_decline(sd_dhcp_client *client) {
- int r;
-
- r = client_send_release_or_decline(client, DHCP_DECLINE);
- if (r <= 0)
- return r;
+static int client_send_release(sd_dhcp_client *client) {
+ assert(client);
- log_dhcp_client(client, "DECLINE");
+ if (!client->send_release)
+ return 0;
- /* This function is mostly called when the acquired address conflicts with another host.
- * Restarting the daemon to acquire another address. */
- r = client_restart(client);
- if (r < 0)
- return r;
+ if (!sd_dhcp_client_is_running(client) || !client->lease || client->bootp)
+ return 0; /* there is nothing to release */
- return 1; /* sent and restarted. */
+ return dhcp_client_send_message(client, DHCP_RELEASE);
}
int sd_dhcp_client_stop(sd_dhcp_client *client) {
DHCP_CLIENT_DONT_DESTROY(client);
- if (client->send_release)
- (void) client_send_release_or_decline(client, DHCP_RELEASE);
+ (void) client_send_release(client);
client_stop(client, SD_DHCP_CLIENT_EVENT_STOP);
return 0;
projects / thirdparty / systemd.git / commitdiff
