+++ /dev/null
-/***
- This file is part of systemd.
-
- Copyright (C) 2013 Intel Corporation. All rights reserved.
-
- systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2.1 of the License, or
- (at your option) any later version.
-
- systemd 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
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public License
- 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 <sys/param.h>
-
-#include "util.h"
-#include "list.h"
-
-#include "dhcp-protocol.h"
-#include "dhcp-internal.h"
-#include "sd-dhcp-client.h"
-
-#define DHCP_CLIENT_MIN_OPTIONS_SIZE 312
-
-#define client_state_machine_check(s, r) \
- do { \
- if (s != DHCP_STATE_BOUND && \
- s != DHCP_STATE_RENEWING && \
- s != DHCP_STATE_REBINDING) { \
- return (r); \
- } \
- } while (false)
-
-struct DHCPLease {
- uint32_t t1;
- uint32_t t2;
- uint32_t lifetime;
- be32_t address;
- be32_t server_address;
- be32_t subnet_mask;
- be32_t router;
- struct in_addr *dns;
- size_t dns_size;
- uint16_t mtu;
- char *domainname;
- char *hostname;
-};
-
-typedef struct DHCPLease DHCPLease;
-
-struct sd_dhcp_client {
- DHCPState state;
- sd_event *event;
- int event_priority;
- sd_event_source *timeout_resend;
- int index;
- int fd;
- union sockaddr_union link;
- sd_event_source *receive_message;
- uint8_t *req_opts;
- size_t req_opts_allocated;
- size_t req_opts_size;
- be32_t last_addr;
- struct ether_addr mac_addr;
- uint32_t xid;
- usec_t start_time;
- unsigned int attempt;
- usec_t request_sent;
- sd_event_source *timeout_t1;
- sd_event_source *timeout_t2;
- sd_event_source *timeout_expire;
- sd_dhcp_client_cb_t cb;
- void *userdata;
- DHCPLease *lease;
-};
-
-static const uint8_t default_req_opts[] = {
- DHCP_OPTION_SUBNET_MASK,
- DHCP_OPTION_ROUTER,
- DHCP_OPTION_HOST_NAME,
- DHCP_OPTION_DOMAIN_NAME,
- DHCP_OPTION_DOMAIN_NAME_SERVER,
- DHCP_OPTION_NTP_SERVER,
-};
-
-static int client_receive_message(sd_event_source *s, int fd,
- uint32_t revents, void *userdata);
-
-int sd_dhcp_client_set_callback(sd_dhcp_client *client, sd_dhcp_client_cb_t cb,
- void *userdata) {
- assert_return(client, -EINVAL);
-
- client->cb = cb;
- client->userdata = userdata;
-
- return 0;
-}
-
-int sd_dhcp_client_set_request_option(sd_dhcp_client *client, uint8_t option) {
- size_t i;
-
- assert_return(client, -EINVAL);
- assert_return (client->state == DHCP_STATE_INIT, -EBUSY);
-
- switch(option) {
- case DHCP_OPTION_PAD:
- case DHCP_OPTION_OVERLOAD:
- case DHCP_OPTION_MESSAGE_TYPE:
- case DHCP_OPTION_PARAMETER_REQUEST_LIST:
- case DHCP_OPTION_END:
- return -EINVAL;
-
- default:
- break;
- }
-
- for (i = 0; i < client->req_opts_size; i++)
- if (client->req_opts[i] == option)
- return -EEXIST;
-
- if (!GREEDY_REALLOC(client->req_opts, client->req_opts_allocated,
- client->req_opts_size + 1))
- return -ENOMEM;
-
- client->req_opts[client->req_opts_size++] = option;
-
- return 0;
-}
-
-int sd_dhcp_client_set_request_address(sd_dhcp_client *client,
- const struct in_addr *last_addr) {
- assert_return(client, -EINVAL);
- assert_return(client->state == DHCP_STATE_INIT, -EBUSY);
-
- if (last_addr)
- client->last_addr = last_addr->s_addr;
- else
- client->last_addr = INADDR_ANY;
-
- return 0;
-}
-
-int sd_dhcp_client_set_index(sd_dhcp_client *client, int interface_index) {
- assert_return(client, -EINVAL);
- assert_return(client->state == DHCP_STATE_INIT, -EBUSY);
- assert_return(interface_index >= -1, -EINVAL);
-
- client->index = interface_index;
-
- return 0;
-}
-
-int sd_dhcp_client_set_mac(sd_dhcp_client *client,
- const struct ether_addr *addr) {
- assert_return(client, -EINVAL);
- assert_return(client->state == DHCP_STATE_INIT, -EBUSY);
-
- memcpy(&client->mac_addr, addr, ETH_ALEN);
-
- return 0;
-}
-
-int sd_dhcp_client_get_address(sd_dhcp_client *client, struct in_addr *addr) {
- assert_return(client, -EINVAL);
- assert_return(addr, -EINVAL);
-
- client_state_machine_check (client->state, -EADDRNOTAVAIL);
-
- addr->s_addr = client->lease->address;
-
- return 0;
-}
-
-int sd_dhcp_client_get_mtu(sd_dhcp_client *client, uint16_t *mtu) {
- assert_return(client, -EINVAL);
- assert_return(mtu, -EINVAL);
-
- client_state_machine_check (client->state, -EADDRNOTAVAIL);
-
- if (client->lease->mtu)
- *mtu = client->lease->mtu;
- else
- return -ENOENT;
-
- return 0;
-}
-
-int sd_dhcp_client_get_dns(sd_dhcp_client *client, struct in_addr **addr, size_t *addr_size) {
- assert_return(client, -EINVAL);
- assert_return(addr, -EINVAL);
- assert_return(addr_size, -EINVAL);
-
- client_state_machine_check (client->state, -EADDRNOTAVAIL);
-
- if (client->lease->dns_size) {
- *addr_size = client->lease->dns_size;
- *addr = client->lease->dns;
- } else
- return -ENOENT;
-
- return 0;
-}
-
-int sd_dhcp_client_get_domainname(sd_dhcp_client *client, const char **domainname) {
- assert_return(client, -EINVAL);
- assert_return(domainname, -EINVAL);
-
- client_state_machine_check (client->state, -EADDRNOTAVAIL);
-
- if (client->lease->domainname)
- *domainname = client->lease->domainname;
- else
- return -ENOENT;
-
- return 0;
-}
-
-int sd_dhcp_client_get_hostname(sd_dhcp_client *client, const char **hostname) {
- assert_return(client, -EINVAL);
- assert_return(hostname, -EINVAL);
-
- client_state_machine_check (client->state, -EADDRNOTAVAIL);
-
- if (client->lease->hostname)
- *hostname = client->lease->hostname;
- else
- return -ENOENT;
-
- return 0;
-}
-
-int sd_dhcp_client_prefixlen(const struct in_addr *addr) {
- int len = 0;
- uint32_t mask;
-
- assert_return(addr, -EADDRNOTAVAIL);
-
- mask = be32toh(addr->s_addr);
- while (mask) {
- len++;
- mask = mask << 1;
- }
-
- return len;
-}
-
-int sd_dhcp_client_get_router(sd_dhcp_client *client, struct in_addr *addr) {
- assert_return(client, -EINVAL);
- assert_return(addr, -EINVAL);
-
- client_state_machine_check (client->state, -EADDRNOTAVAIL);
-
- addr->s_addr = client->lease->router;
-
- return 0;
-}
-
-int sd_dhcp_client_get_netmask(sd_dhcp_client *client, struct in_addr *addr) {
- assert_return(client, -EINVAL);
- assert_return(addr, -EINVAL);
-
- client_state_machine_check (client->state, -EADDRNOTAVAIL);
-
- addr->s_addr = client->lease->subnet_mask;
-
- return 0;
-}
-
-static int client_notify(sd_dhcp_client *client, int event) {
- if (client->cb)
- client->cb(client, event, client->userdata);
-
- return 0;
-}
-
-static void lease_free(DHCPLease *lease) {
- if (!lease)
- return;
-
- free(lease->hostname);
- free(lease->domainname);
- free(lease->dns);
- free(lease);
-}
-
-DEFINE_TRIVIAL_CLEANUP_FUNC(DHCPLease*, lease_free);
-#define _cleanup_lease_free_ _cleanup_(lease_freep)
-
-static int client_stop(sd_dhcp_client *client, int error) {
- assert_return(client, -EINVAL);
-
- client->receive_message =
- sd_event_source_unref(client->receive_message);
-
- if (client->fd >= 0)
- close(client->fd);
- client->fd = -1;
-
- client->timeout_resend = sd_event_source_unref(client->timeout_resend);
-
- client->timeout_t1 = sd_event_source_unref(client->timeout_t1);
- client->timeout_t2 = sd_event_source_unref(client->timeout_t2);
- client->timeout_expire = sd_event_source_unref(client->timeout_expire);
-
- client->attempt = 1;
-
- client_notify(client, error);
-
- switch (client->state) {
-
- case DHCP_STATE_INIT:
- case DHCP_STATE_SELECTING:
- case DHCP_STATE_REQUESTING:
- case DHCP_STATE_BOUND:
-
- client->start_time = 0;
- client->state = DHCP_STATE_INIT;
- break;
-
- case DHCP_STATE_INIT_REBOOT:
- case DHCP_STATE_REBOOTING:
- case DHCP_STATE_RENEWING:
- case DHCP_STATE_REBINDING:
-
- break;
- }
-
- if (client->lease) {
- lease_free(client->lease);
- client->lease = NULL;
- }
-
- return 0;
-}
-
-static int client_packet_init(sd_dhcp_client *client, uint8_t type,
- DHCPMessage *message, uint16_t secs,
- uint8_t **opt, size_t *optlen) {
- int err;
- be16_t max_size;
-
- *opt = (uint8_t *)(message + 1);
-
- if (*optlen < 4)
- return -ENOBUFS;
- *optlen -= 4;
-
- message->op = BOOTREQUEST;
- message->htype = 1;
- message->hlen = ETHER_ADDR_LEN;
- message->xid = htobe32(client->xid);
-
- /* Although 'secs' field is a SHOULD in RFC 2131, certain DHCP servers
- refuse to issue an DHCP lease if 'secs' is set to zero */
- message->secs = htobe16(secs);
-
- if (client->state == DHCP_STATE_RENEWING ||
- client->state == DHCP_STATE_REBINDING)
- message->ciaddr = client->lease->address;
-
- memcpy(&message->chaddr, &client->mac_addr, ETH_ALEN);
- (*opt)[0] = 0x63;
- (*opt)[1] = 0x82;
- (*opt)[2] = 0x53;
- (*opt)[3] = 0x63;
-
- *opt += 4;
-
- err = dhcp_option_append(opt, optlen, DHCP_OPTION_MESSAGE_TYPE, 1,
- &type);
- if (err < 0)
- return err;
-
- /* Some DHCP servers will refuse to issue an DHCP lease if the Cliient
- Identifier option is not set */
- err = dhcp_option_append(opt, optlen, DHCP_OPTION_CLIENT_IDENTIFIER,
- ETH_ALEN, &client->mac_addr);
- if (err < 0)
- return err;
-
- if (type == DHCP_DISCOVER || type == DHCP_REQUEST) {
- err = dhcp_option_append(opt, optlen,
- DHCP_OPTION_PARAMETER_REQUEST_LIST,
- client->req_opts_size,
- client->req_opts);
- if (err < 0)
- return err;
-
- /* Some DHCP servers will send bigger DHCP packets than the
- defined default size unless the Maximum Messge Size option
- is explicitely set */
- max_size = htobe16(DHCP_IP_UDP_SIZE + DHCP_MESSAGE_SIZE +
- DHCP_CLIENT_MIN_OPTIONS_SIZE);
- err = dhcp_option_append(opt, optlen,
- DHCP_OPTION_MAXIMUM_MESSAGE_SIZE,
- 2, &max_size);
- if (err < 0)
- return err;
- }
-
- return 0;
-}
-
-static uint16_t client_checksum(void *buf, int len) {
- uint32_t sum;
- uint16_t *check;
- int i;
- uint8_t *odd;
-
- sum = 0;
- check = buf;
-
- for (i = 0; i < len / 2 ; i++)
- sum += check[i];
-
- if (len & 0x01) {
- odd = buf;
- sum += odd[len - 1];
- }
-
- while (sum >> 16)
- sum = (sum & 0xffff) + (sum >> 16);
-
- return ~sum;
-}
-
-static void client_append_ip_headers(DHCPPacket *packet, uint16_t len) {
- packet->ip.version = IPVERSION;
- packet->ip.ihl = DHCP_IP_SIZE / 4;
- packet->ip.tot_len = htobe16(len);
-
- packet->ip.protocol = IPPROTO_UDP;
- packet->ip.saddr = INADDR_ANY;
- packet->ip.daddr = INADDR_BROADCAST;
-
- packet->udp.source = htobe16(DHCP_PORT_CLIENT);
- packet->udp.dest = htobe16(DHCP_PORT_SERVER);
- packet->udp.len = htobe16(len - DHCP_IP_SIZE);
-
- packet->ip.check = packet->udp.len;
- packet->udp.check = client_checksum(&packet->ip.ttl, len - 8);
-
- packet->ip.ttl = IPDEFTTL;
- packet->ip.check = 0;
- packet->ip.check = client_checksum(&packet->ip, DHCP_IP_SIZE);
-}
-
-static int client_send_discover(sd_dhcp_client *client, uint16_t secs) {
- int err = 0;
- _cleanup_free_ DHCPPacket *discover;
- size_t optlen, len;
- uint8_t *opt;
-
- optlen = DHCP_CLIENT_MIN_OPTIONS_SIZE;
- len = sizeof(DHCPPacket) + optlen;
-
- discover = malloc0(len);
-
- if (!discover)
- return -ENOMEM;
-
- err = client_packet_init(client, DHCP_DISCOVER, &discover->dhcp,
- secs, &opt, &optlen);
- if (err < 0)
- return err;
-
- if (client->last_addr != INADDR_ANY) {
- err = dhcp_option_append(&opt, &optlen,
- DHCP_OPTION_REQUESTED_IP_ADDRESS,
- 4, &client->last_addr);
- if (err < 0)
- return err;
- }
-
- err = dhcp_option_append(&opt, &optlen, DHCP_OPTION_END, 0, NULL);
- if (err < 0)
- return err;
-
- client_append_ip_headers(discover, len);
-
- err = dhcp_network_send_raw_socket(client->fd, &client->link,
- discover, len);
-
- return err;
-}
-
-static int client_send_request(sd_dhcp_client *client, uint16_t secs) {
- _cleanup_free_ DHCPPacket *request;
- size_t optlen, len;
- int err;
- uint8_t *opt;
-
- optlen = DHCP_CLIENT_MIN_OPTIONS_SIZE;
- len = DHCP_MESSAGE_SIZE + optlen;
-
- request = malloc0(len);
- if (!request)
- return -ENOMEM;
-
- err = client_packet_init(client, DHCP_REQUEST, &request->dhcp, secs,
- &opt, &optlen);
- if (err < 0)
- return err;
-
- if (client->state == DHCP_STATE_REQUESTING) {
- err = dhcp_option_append(&opt, &optlen,
- DHCP_OPTION_REQUESTED_IP_ADDRESS,
- 4, &client->lease->address);
- if (err < 0)
- return err;
-
- err = dhcp_option_append(&opt, &optlen,
- DHCP_OPTION_SERVER_IDENTIFIER,
- 4, &client->lease->server_address);
- if (err < 0)
- return err;
- }
-
- err = dhcp_option_append(&opt, &optlen, DHCP_OPTION_END, 0, NULL);
- if (err < 0)
- return err;
-
- if (client->state == DHCP_STATE_RENEWING) {
- err = dhcp_network_send_udp_socket(client->fd,
- client->lease->server_address,
- &request->dhcp,
- len - DHCP_IP_UDP_SIZE);
- } else {
- client_append_ip_headers(request, len);
-
- err = dhcp_network_send_raw_socket(client->fd, &client->link,
- request, len);
- }
-
- return err;
-}
-
-static int client_timeout_resend(sd_event_source *s, uint64_t usec,
- void *userdata) {
- sd_dhcp_client *client = userdata;
- usec_t next_timeout = 0;
- uint32_t time_left;
- uint16_t secs;
- int r = 0;
-
- assert(s);
- assert(client);
- assert(client->event);
-
- switch (client->state) {
- case DHCP_STATE_RENEWING:
-
- time_left = (client->lease->t2 - client->lease->t1)/2;
- if (time_left < 60)
- time_left = 60;
-
- next_timeout = usec + time_left * USEC_PER_SEC;
-
- break;
-
- case DHCP_STATE_REBINDING:
-
- time_left = (client->lease->lifetime - client->lease->t2)/2;
- if (time_left < 60)
- time_left = 60;
-
- next_timeout = usec + time_left * USEC_PER_SEC;
- break;
-
- case DHCP_STATE_INIT:
- case DHCP_STATE_INIT_REBOOT:
- case DHCP_STATE_REBOOTING:
- case DHCP_STATE_SELECTING:
- case DHCP_STATE_REQUESTING:
- case DHCP_STATE_BOUND:
-
- if (client->attempt < 64)
- client->attempt *= 2;
-
- next_timeout = usec + (client->attempt - 1) * USEC_PER_SEC;
-
- break;
- }
-
- next_timeout += (random_u32() & 0x1fffff);
-
- r = sd_event_add_monotonic(client->event, next_timeout,
- 10 * USEC_PER_MSEC,
- client_timeout_resend, client,
- &client->timeout_resend);
- if (r < 0)
- goto error;
-
- r = sd_event_source_set_priority(client->timeout_resend, client->event_priority);
- if (r < 0)
- goto error;
-
- secs = (usec - client->start_time) / USEC_PER_SEC;
-
- switch (client->state) {
- case DHCP_STATE_INIT:
- r = client_send_discover(client, secs);
- if (r >= 0) {
- client->state = DHCP_STATE_SELECTING;
- client->attempt = 1;
- } else {
- if (client->attempt >= 64)
- goto error;
- }
-
- break;
-
- case DHCP_STATE_SELECTING:
- r = client_send_discover(client, secs);
- if (r < 0 && client->attempt >= 64)
- goto error;
-
- break;
-
- case DHCP_STATE_REQUESTING:
- case DHCP_STATE_RENEWING:
- case DHCP_STATE_REBINDING:
- r = client_send_request(client, secs);
- if (r < 0 && client->attempt >= 64)
- goto error;
-
- client->request_sent = usec;
-
- break;
-
- case DHCP_STATE_INIT_REBOOT:
- case DHCP_STATE_REBOOTING:
- case DHCP_STATE_BOUND:
-
- break;
- }
-
- return 0;
-
-error:
- client_stop(client, r);
-
- /* Errors were dealt with when stopping the client, don't spill
- errors into the event loop handler */
- return 0;
-}
-
-static int client_initialize_events(sd_dhcp_client *client, usec_t usec) {
- int r;
-
- assert(client);
- assert(client->event);
-
- r = sd_event_add_io(client->event, client->fd, EPOLLIN,
- client_receive_message, client,
- &client->receive_message);
- if (r < 0)
- goto error;
-
- r = sd_event_source_set_priority(client->receive_message, client->event_priority);
- if (r < 0)
- goto error;
-
- r = sd_event_add_monotonic(client->event, usec, 0,
- client_timeout_resend, client,
- &client->timeout_resend);
- if (r < 0)
- goto error;
-
- r = sd_event_source_set_priority(client->timeout_resend, client->event_priority);
-
-error:
- if (r < 0)
- client_stop(client, r);
-
- return 0;
-
-}
-
-static int client_timeout_expire(sd_event_source *s, uint64_t usec,
- void *userdata) {
- sd_dhcp_client *client = userdata;
-
- client_stop(client, DHCP_EVENT_EXPIRED);
-
- return 0;
-}
-
-static int client_timeout_t2(sd_event_source *s, uint64_t usec, void *userdata) {
- sd_dhcp_client *client = userdata;
- int r;
-
- if (client->fd >= 0) {
- client->receive_message =
- sd_event_source_unref(client->receive_message);
- close(client->fd);
- client->fd = -1;
- }
-
- client->state = DHCP_STATE_REBINDING;
- client->attempt = 1;
-
- r = dhcp_network_bind_raw_socket(client->index, &client->link);
- if (r < 0) {
- client_stop(client, r);
- return 0;
- }
-
- client->fd = r;
-
- return client_initialize_events(client, usec);
-}
-
-static int client_timeout_t1(sd_event_source *s, uint64_t usec, void *userdata) {
- sd_dhcp_client *client = userdata;
- int r;
-
- client->state = DHCP_STATE_RENEWING;
- client->attempt = 1;
-
- r = dhcp_network_bind_udp_socket(client->index,
- client->lease->address);
- if (r < 0) {
- client_stop(client, r);
- return 0;
- }
-
- client->fd = r;
-
- return client_initialize_events(client, usec);
-}
-
-static int client_parse_offer(uint8_t code, uint8_t len, const uint8_t *option,
- void *user_data) {
- DHCPLease *lease = user_data;
- be32_t val;
-
- switch(code) {
-
- case DHCP_OPTION_IP_ADDRESS_LEASE_TIME:
- if (len == 4) {
- memcpy(&val, option, 4);
- lease->lifetime = be32toh(val);
- }
-
- break;
-
- case DHCP_OPTION_SERVER_IDENTIFIER:
- if (len >= 4)
- memcpy(&lease->server_address, option, 4);
-
- break;
-
- case DHCP_OPTION_SUBNET_MASK:
- if (len >= 4)
- memcpy(&lease->subnet_mask, option, 4);
-
- break;
-
- case DHCP_OPTION_ROUTER:
- if (len >= 4)
- memcpy(&lease->router, option, 4);
-
- break;
-
- case DHCP_OPTION_DOMAIN_NAME_SERVER:
- if (len >= 4) {
- unsigned i;
-
- lease->dns_size = len / 4;
-
- free(lease->dns);
- lease->dns = new0(struct in_addr, lease->dns_size);
- if (!lease->dns)
- return -ENOMEM;
-
- for (i = 0; i < lease->dns_size; i++) {
- memcpy(&lease->dns[i].s_addr, option + 4 * i, 4);
- }
- }
-
- break;
-
- case DHCP_OPTION_INTERFACE_MTU:
- if (len >= 2) {
- be16_t mtu;
-
- memcpy(&mtu, option, 2);
- lease->mtu = be16toh(mtu);
-
- if (lease->mtu < 68)
- lease->mtu = 0;
- }
-
- break;
-
- case DHCP_OPTION_DOMAIN_NAME:
- if (len >= 1) {
- free(lease->domainname);
- lease->domainname = strndup((const char *)option, len);
- }
-
- break;
-
- case DHCP_OPTION_HOST_NAME:
- if (len >= 1) {
- free(lease->hostname);
- lease->hostname = strndup((const char *)option, len);
- }
-
- break;
-
- case DHCP_OPTION_RENEWAL_T1_TIME:
- if (len == 4) {
- memcpy(&val, option, 4);
- lease->t1 = be32toh(val);
- }
-
- break;
-
- case DHCP_OPTION_REBINDING_T2_TIME:
- if (len == 4) {
- memcpy(&val, option, 4);
- lease->t2 = be32toh(val);
- }
-
- break;
- }
-
- return 0;
-}
-
-static int client_verify_headers(sd_dhcp_client *client, DHCPPacket *message,
- size_t len) {
- size_t hdrlen;
-
- if (len < (DHCP_IP_UDP_SIZE + DHCP_MESSAGE_SIZE))
- return -EINVAL;
-
- hdrlen = message->ip.ihl * 4;
- if (hdrlen < 20 || hdrlen > len || client_checksum(&message->ip,
- hdrlen))
- return -EINVAL;
-
- message->ip.check = message->udp.len;
- message->ip.ttl = 0;
-
- if (hdrlen + be16toh(message->udp.len) > len ||
- client_checksum(&message->ip.ttl, be16toh(message->udp.len) + 12))
- return -EINVAL;
-
- if (be16toh(message->udp.source) != DHCP_PORT_SERVER ||
- be16toh(message->udp.dest) != DHCP_PORT_CLIENT)
- return -EINVAL;
-
- if (message->dhcp.op != BOOTREPLY)
- return -EINVAL;
-
- if (be32toh(message->dhcp.xid) != client->xid)
- return -EINVAL;
-
- if (memcmp(&message->dhcp.chaddr[0], &client->mac_addr.ether_addr_octet,
- ETHER_ADDR_LEN))
- return -EINVAL;
-
- return 0;
-}
-
-static int client_receive_offer(sd_dhcp_client *client, DHCPPacket *offer,
- size_t len) {
- _cleanup_lease_free_ DHCPLease *lease = NULL;
- int r;
-
- r = client_verify_headers(client, offer, len);
- if (r < 0)
- return r;
-
- lease = new0(DHCPLease, 1);
- if (!lease)
- return -ENOMEM;
-
- len = len - DHCP_IP_UDP_SIZE;
- r = dhcp_option_parse(&offer->dhcp, len, client_parse_offer,
- lease);
- if (r != DHCP_OFFER)
- return -ENOMSG;
-
- lease->address = offer->dhcp.yiaddr;
-
- if (lease->address == INADDR_ANY ||
- lease->server_address == INADDR_ANY ||
- lease->subnet_mask == INADDR_ANY ||
- lease->lifetime == 0)
- return -ENOMSG;
-
- client->lease = lease;
- lease = NULL;
-
- return 0;
-}
-
-static int client_receive_ack(sd_dhcp_client *client, const uint8_t *buf,
- size_t len) {
- DHCPPacket *ack;
- DHCPMessage *dhcp;
- _cleanup_lease_free_ DHCPLease *lease = NULL;
- int r;
-
- if (client->state == DHCP_STATE_RENEWING) {
- dhcp = (DHCPMessage *)buf;
- } else {
- ack = (DHCPPacket *)buf;
-
- r = client_verify_headers(client, ack, len);
- if (r < 0)
- return r;
-
- dhcp = &ack->dhcp;
- len -= DHCP_IP_UDP_SIZE;
- }
-
- lease = new0(DHCPLease, 1);
- if (!lease)
- return -ENOMEM;
-
- r = dhcp_option_parse(dhcp, len, client_parse_offer, lease);
- if (r == DHCP_NAK)
- return DHCP_EVENT_NO_LEASE;
-
- if (r != DHCP_ACK)
- return -ENOMSG;
-
- lease->address = dhcp->yiaddr;
-
- if (lease->address == INADDR_ANY ||
- lease->server_address == INADDR_ANY ||
- lease->subnet_mask == INADDR_ANY || lease->lifetime == 0)
- return -ENOMSG;
-
- r = DHCP_EVENT_IP_ACQUIRE;
- if (client->lease) {
- if (client->lease->address != lease->address ||
- client->lease->subnet_mask != lease->subnet_mask ||
- client->lease->router != lease->router) {
- r = DHCP_EVENT_IP_CHANGE;
- }
-
- lease_free(client->lease);
- }
-
- client->lease = lease;
- lease = NULL;
-
- return r;
-}
-
-static uint64_t client_compute_timeout(uint64_t request_sent,
- uint32_t lifetime) {
- return request_sent + (lifetime - 3) * USEC_PER_SEC +
- + (random_u32() & 0x1fffff);
-}
-
-static int client_set_lease_timeouts(sd_dhcp_client *client, uint64_t usec) {
- uint64_t next_timeout;
- int r;
-
- assert(client);
- assert(client->event);
-
- if (client->lease->lifetime < 10)
- return -EINVAL;
-
- client->timeout_t1 = sd_event_source_unref(client->timeout_t1);
- client->timeout_t2 = sd_event_source_unref(client->timeout_t2);
- client->timeout_expire = sd_event_source_unref(client->timeout_expire);
-
- if (!client->lease->t1)
- client->lease->t1 = client->lease->lifetime / 2;
-
- next_timeout = client_compute_timeout(client->request_sent,
- client->lease->t1);
- if (next_timeout < usec)
- return -EINVAL;
-
- r = sd_event_add_monotonic(client->event, next_timeout,
- 10 * USEC_PER_MSEC,
- client_timeout_t1, client,
- &client->timeout_t1);
- if (r < 0)
- return r;
-
- r = sd_event_source_set_priority(client->timeout_t1, client->event_priority);
- if (r < 0)
- return r;
-
- if (!client->lease->t2)
- client->lease->t2 = client->lease->lifetime * 7 / 8;
-
- if (client->lease->t2 < client->lease->t1)
- return -EINVAL;
-
- if (client->lease->lifetime < client->lease->t2)
- return -EINVAL;
-
- next_timeout = client_compute_timeout(client->request_sent,
- client->lease->t2);
- if (next_timeout < usec)
- return -EINVAL;
-
- r = sd_event_add_monotonic(client->event, next_timeout,
- 10 * USEC_PER_MSEC,
- client_timeout_t2, client,
- &client->timeout_t2);
- if (r < 0)
- return r;
-
- r = sd_event_source_set_priority(client->timeout_t2, client->event_priority);
- if (r < 0)
- return r;
-
- next_timeout = client_compute_timeout(client->request_sent,
- client->lease->lifetime);
- if (next_timeout < usec)
- return -EINVAL;
-
- r = sd_event_add_monotonic(client->event, next_timeout,
- 10 * USEC_PER_MSEC,
- client_timeout_expire, client,
- &client->timeout_expire);
- if (r < 0)
- return r;
-
- r = sd_event_source_set_priority(client->timeout_expire, client->event_priority);
- if (r < 0)
- return r;
-
- return 0;
-}
-
-static int client_receive_message(sd_event_source *s, int fd,
- uint32_t revents, void *userdata) {
- sd_dhcp_client *client = userdata;
- uint8_t buf[sizeof(DHCPPacket) + DHCP_CLIENT_MIN_OPTIONS_SIZE];
- int buflen = sizeof(buf);
- int len, r = 0, notify_event = 0;
- DHCPPacket *message;
- usec_t time_now;
-
- assert(s);
- assert(client);
- assert(client->event);
-
- len = read(fd, &buf, buflen);
- if (len < 0)
- return 0;
-
- r = sd_event_get_now_monotonic(client->event, &time_now);
- if (r < 0)
- goto error;
-
- switch (client->state) {
- case DHCP_STATE_SELECTING:
-
- message = (DHCPPacket *)&buf;
-
- if (client_receive_offer(client, message, len) >= 0) {
-
- client->timeout_resend =
- sd_event_source_unref(client->timeout_resend);
-
- client->state = DHCP_STATE_REQUESTING;
- client->attempt = 1;
-
- r = sd_event_add_monotonic(client->event, time_now, 0,
- client_timeout_resend,
- client,
- &client->timeout_resend);
- if (r < 0)
- goto error;
-
- r = sd_event_source_set_priority(client->timeout_resend, client->event_priority);
- if (r < 0)
- goto error;
- }
-
- break;
-
- case DHCP_STATE_REQUESTING:
- case DHCP_STATE_RENEWING:
- case DHCP_STATE_REBINDING:
-
- r = client_receive_ack(client, buf, len);
-
- if (r == DHCP_EVENT_NO_LEASE)
- goto error;
-
- if (r >= 0) {
- client->timeout_resend =
- sd_event_source_unref(client->timeout_resend);
-
- if (client->state == DHCP_STATE_REQUESTING)
- notify_event = DHCP_EVENT_IP_ACQUIRE;
- else if (r != DHCP_EVENT_IP_ACQUIRE)
- notify_event = r;
-
- client->state = DHCP_STATE_BOUND;
- client->attempt = 1;
-
- client->last_addr = client->lease->address;
-
- r = client_set_lease_timeouts(client, time_now);
- if (r < 0)
- goto error;
-
- if (notify_event)
- client_notify(client, notify_event);
-
- client->receive_message =
- sd_event_source_unref(client->receive_message);
- close(client->fd);
- client->fd = -1;
- }
-
- r = 0;
-
- break;
-
- case DHCP_STATE_INIT:
- case DHCP_STATE_INIT_REBOOT:
- case DHCP_STATE_REBOOTING:
- case DHCP_STATE_BOUND:
-
- break;
- }
-
-error:
- if (r < 0 || r == DHCP_EVENT_NO_LEASE)
- return client_stop(client, r);
-
- return 0;
-}
-
-int sd_dhcp_client_start(sd_dhcp_client *client) {
- int r;
-
- assert_return(client, -EINVAL);
- assert_return(client->event, -EINVAL);
- assert_return(client->index > 0, -EINVAL);
- assert_return(client->state == DHCP_STATE_INIT ||
- client->state == DHCP_STATE_INIT_REBOOT, -EBUSY);
-
- client->xid = random_u32();
-
- r = dhcp_network_bind_raw_socket(client->index, &client->link);
-
- if (r < 0) {
- client_stop(client, r);
- return r;
- }
-
- client->fd = r;
- client->start_time = now(CLOCK_MONOTONIC);
-
- return client_initialize_events(client, client->start_time);
-}
-
-int sd_dhcp_client_stop(sd_dhcp_client *client) {
- return client_stop(client, DHCP_EVENT_STOP);
-}
-
-int sd_dhcp_client_attach_event(sd_dhcp_client *client, sd_event *event, int priority) {
- int r;
-
- assert_return(client, -EINVAL);
- assert_return(!client->event, -EBUSY);
-
- if (event)
- client->event = sd_event_ref(event);
- else {
- r = sd_event_default(&client->event);
- if (r < 0)
- return 0;
- }
-
- client->event_priority = priority;
-
- return 0;
-}
-
-int sd_dhcp_client_detach_event(sd_dhcp_client *client) {
- assert_return(client, -EINVAL);
-
- client->event = sd_event_unref(client->event);
-
- return 0;
-}
-
-sd_event *sd_dhcp_client_get_event(sd_dhcp_client *client) {
- if (!client)
- return NULL;
-
- return client->event;
-}
-
-void sd_dhcp_client_free(sd_dhcp_client *client) {
- if (!client)
- return;
-
- sd_dhcp_client_stop(client);
- sd_dhcp_client_detach_event(client);
-
- free(client->req_opts);
- free(client);
-}
-
-DEFINE_TRIVIAL_CLEANUP_FUNC(sd_dhcp_client*, sd_dhcp_client_free);
-#define _cleanup_dhcp_client_free_ _cleanup_(sd_dhcp_client_freep)
-
-int sd_dhcp_client_new(sd_dhcp_client **ret) {
- _cleanup_dhcp_client_free_ sd_dhcp_client *client = NULL;
-
- assert_return(ret, -EINVAL);
-
- client = new0(sd_dhcp_client, 1);
- if (!client)
- return -ENOMEM;
-
- client->state = DHCP_STATE_INIT;
- client->index = -1;
- client->fd = -1;
- client->attempt = 1;
-
- client->req_opts_size = ELEMENTSOF(default_req_opts);
-
- client->req_opts = memdup(default_req_opts, client->req_opts_size);
- if (!client->req_opts)
- return -ENOMEM;
-
- *ret = client;
- client = NULL;
-
- return 0;
-}
~ianmdlvl / elogind.git / blobdiff