static int client_receive_message_udp(sd_event_source *s, int fd,
uint32_t revents, void *userdata) {
sd_dhcp_client *client = userdata;
_cleanup_free_ DHCPMessage *message = NULL;
int buflen = 0, len, r;
assert(s);
assert(client);
r = ioctl(fd, FIONREAD, &buflen);
if (r < 0 || buflen <= 0)
buflen = sizeof(DHCPMessage) + DHCP_MIN_OPTIONS_SIZE;
message = malloc0(buflen);
if (!message)
return -ENOMEM;
len = read(fd, message, buflen);
if (len < 0) {
log_dhcp_client(client, "could not receive message from UDP "
"socket: %s", strerror(errno));
return 0;
} else if ((size_t)len < sizeof(DHCPMessage))
return 0;
return client_handle_message(client, message, len);
}
static int client_receive_message_udp(sd_event_source *s, int fd,
uint32_t revents, void *userdata) {
sd_dhcp_client *client = userdata;
_cleanup_free_ DHCPMessage *message = NULL;
int buflen = 0, len, r;
assert(s);
assert(client);
r = ioctl(fd, FIONREAD, &buflen);
if (r < 0)
return r;
if (buflen < 0)
/* this can't be right */
return -EIO;
message = malloc0(buflen);
if (!message)
return -ENOMEM;
len = read(fd, message, buflen);
if (len < 0) {
log_dhcp_client(client, "could not receive message from UDP "
"socket: %m");
return 0;
} else if ((size_t)len < sizeof(DHCPMessage))
return 0;
return client_handle_message(client, message, len);
}
static int client_receive_message_raw(sd_event_source *s, int fd,
uint32_t revents, void *userdata) {
sd_dhcp_client *client = userdata;
_cleanup_free_ DHCPPacket *packet = NULL;
uint8_t cmsgbuf[CMSG_LEN(sizeof(struct tpacket_auxdata))];
struct iovec iov = {};
struct msghdr msg = {
.msg_iov = &iov,
.msg_iovlen = 1,
.msg_control = cmsgbuf,
.msg_controllen = sizeof(cmsgbuf),
};
struct cmsghdr *cmsg;
bool checksum = true;
int buflen = 0, len, r;
assert(s);
assert(client);
r = ioctl(fd, FIONREAD, &buflen);
if (r < 0 || buflen <= 0)
buflen = sizeof(DHCPPacket) + DHCP_MIN_OPTIONS_SIZE;
packet = malloc0(buflen);
if (!packet)
return -ENOMEM;
iov.iov_base = packet;
iov.iov_len = buflen;
len = recvmsg(fd, &msg, 0);
if (len < 0) {
log_dhcp_client(client, "could not receive message from raw "
"socket: %s", strerror(errno));
return 0;
} else if ((size_t)len < sizeof(DHCPPacket))
return 0;
for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
if (cmsg->cmsg_level == SOL_PACKET &&
cmsg->cmsg_type == PACKET_AUXDATA &&
cmsg->cmsg_len == CMSG_LEN(sizeof(struct tpacket_auxdata))) {
struct tpacket_auxdata *aux = (struct tpacket_auxdata*)CMSG_DATA(cmsg);
checksum = !(aux->tp_status & TP_STATUS_CSUMNOTREADY);
break;
}
}
r = dhcp_packet_verify_headers(packet, len, checksum);
if (r < 0)
return 0;
len -= DHCP_IP_UDP_SIZE;
return client_handle_message(client, &packet->dhcp, len);
}
int sd_dhcp_client_start(sd_dhcp_client *client) {
int r;
assert_return(client, -EINVAL);
r = client_initialize(client);
if (r < 0)
return r;
if (client->last_addr)
client->state = DHCP_STATE_INIT_REBOOT;
r = client_start(client);
if (r >= 0)
log_dhcp_client(client, "STARTED on ifindex %u with address %s",
client->index,
ether_ntoa(&client->client_id.mac_addr));
return r;
}
