diff options
Diffstat (limited to 'src/libsystemd-dhcp/dhcp-client.c')
| -rw-r--r-- | src/libsystemd-dhcp/dhcp-client.c | 195 |
1 files changed, 193 insertions, 2 deletions
diff --git a/src/libsystemd-dhcp/dhcp-client.c b/src/libsystemd-dhcp/dhcp-client.c index e9c4700081..d3ba7ae8ed 100644 --- a/src/libsystemd-dhcp/dhcp-client.c +++ b/src/libsystemd-dhcp/dhcp-client.c @@ -32,17 +32,31 @@ #define DHCP_CLIENT_MIN_OPTIONS_SIZE 312 +struct DHCPLease { + uint32_t lifetime; + uint32_t address; + uint32_t server_address; + uint32_t subnet_mask; + uint32_t router; +}; + +typedef struct DHCPLease DHCPLease; + struct sd_dhcp_client { DHCPState state; sd_event *event; 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_size; uint32_t last_addr; struct ether_addr mac_addr; uint32_t xid; usec_t start_time; + DHCPLease *lease; }; static const uint8_t default_req_opts[] = { @@ -128,6 +142,13 @@ static int client_stop(sd_dhcp_client *client, int error) assert_return(client->state != DHCP_STATE_INIT && client->state != DHCP_STATE_INIT_REBOOT, -EALREADY); + 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); switch (client->state) { @@ -135,6 +156,7 @@ static int client_stop(sd_dhcp_client *client, int error) case DHCP_STATE_INIT: case DHCP_STATE_SELECTING: + client->start_time = 0; client->state = DHCP_STATE_INIT; break; @@ -148,6 +170,11 @@ static int client_stop(sd_dhcp_client *client, int error) break; } + if (client->lease) { + free(client->lease); + client->lease = NULL; + } + return 0; } @@ -278,9 +305,10 @@ static int client_send_discover(sd_dhcp_client *client, uint16_t secs) discover->ip.check = client_checksum(&discover->ip, sizeof(discover->ip)); - err = dhcp_network_send_raw_packet(client->index, discover, len); + err = dhcp_network_send_raw_socket(client->fd, &client->link, + discover, len); - return 0; + return err; } static int client_timeout_resend(sd_event_source *s, uint64_t usec, @@ -334,6 +362,154 @@ error: return 0; } +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; + } + + return 0; +} + +static int client_receive_offer(sd_dhcp_client *client, DHCPPacket *offer, + size_t len) +{ + size_t hdrlen; + DHCPLease *lease; + + if (len < (DHCP_IP_UDP_SIZE + DHCP_MESSAGE_SIZE)) + return -EINVAL; + + hdrlen = offer->ip.ihl * 4; + if (hdrlen < 20 || hdrlen > len || client_checksum(&offer->ip, + hdrlen)) + return -EINVAL; + + offer->ip.check = offer->udp.len; + offer->ip.ttl = 0; + + if (hdrlen + be16toh(offer->udp.len) > len || + client_checksum(&offer->ip.ttl, be16toh(offer->udp.len) + 12)) + return -EINVAL; + + if (be16toh(offer->udp.source) != DHCP_PORT_SERVER || + be16toh(offer->udp.dest) != DHCP_PORT_CLIENT) + return -EINVAL; + + if (offer->dhcp.op != BOOTREPLY) + return -EINVAL; + + if (be32toh(offer->dhcp.xid) != client->xid) + return -EINVAL; + + if (memcmp(&offer->dhcp.chaddr[0], &client->mac_addr.ether_addr_octet, + ETHER_ADDR_LEN)) + return -EINVAL; + + lease = new0(DHCPLease, 1); + if (!lease) + return -ENOMEM; + + len = len - DHCP_IP_UDP_SIZE; + if (dhcp_option_parse(&offer->dhcp, len, client_parse_offer, + lease) != DHCP_OFFER) + goto error; + + lease->address = offer->dhcp.yiaddr; + + if (lease->address == INADDR_ANY || + lease->server_address == INADDR_ANY || + lease->subnet_mask == INADDR_ANY || + lease->lifetime == 0) + goto error; + + client->lease = lease; + + return 0; + +error: + free(lease); + + return -ENOMSG; +} + +static int client_receive_raw_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; + DHCPPacket *message; + + len = read(fd, &buf, buflen); + if (len < 0) + goto error; + + message = (DHCPPacket *)&buf; + + switch (client->state) { + case DHCP_STATE_SELECTING: + + if (client_receive_offer(client, message, len) >= 0) { + + client->receive_message = + sd_event_source_unref(client->receive_message); + close(client->fd); + client->fd = -1; + + client->timeout_resend = + sd_event_source_unref(client->timeout_resend); + + client->state = DHCP_STATE_REQUESTING; + } + + break; + + case DHCP_STATE_INIT: + case DHCP_STATE_INIT_REBOOT: + case DHCP_STATE_REBOOTING: + case DHCP_STATE_REQUESTING: + case DHCP_STATE_BOUND: + case DHCP_STATE_RENEWING: + case DHCP_STATE_REBINDING: + + break; + } + +error: + return 0; +} + int sd_dhcp_client_start(sd_dhcp_client *client) { int err; @@ -345,6 +521,20 @@ int sd_dhcp_client_start(sd_dhcp_client *client) client->xid = random_u(); + client->fd = dhcp_network_bind_raw_socket(client->index, + &client->link); + + if (client->fd < 0) { + err = client->fd; + goto error; + } + + err = sd_event_add_io(client->event, client->fd, EPOLLIN, + client_receive_raw_message, client, + &client->receive_message); + if (err < 0) + goto error; + err = sd_event_add_monotonic(client->event, now(CLOCK_MONOTONIC), 0, client_timeout_resend, client, &client->timeout_resend); @@ -377,6 +567,7 @@ sd_dhcp_client *sd_dhcp_client_new(sd_event *event) client->event = sd_event_ref(event); client->state = DHCP_STATE_INIT; client->index = -1; + client->fd = -1; client->req_opts_size = ELEMENTSOF(default_req_opts); |