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lsp_client.c
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lsp_client.c
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#ifndef LSP_CLIENT_C
#define LSP_CLIENT_C
#include "api.h"
lsp_client * global_client;
// Setting client LSP Parameters
double epoch_lth = 2;
double epoch_cnt = 5;
struct itimerval timer_client;
void lsp_client_resend_lastmsgbuf(lsp_client* a_client);
void lsp_client_ack_lastmsgbuf(lsp_client* a_client);
bool lsp_client_store_lastmsgbuf(lsp_client* a_client, uint8_t* buf, int len);
static void client_sig_timer(int i) {
DEBUG("client_sig_timer");
if (global_client->lc_epoch_recv_flag) {
global_client->lc_epoch_pass_num = 0;
global_client->lc_epoch_recv_flag = 0;
} else {
global_client->lc_epoch_pass_num++;
}
// timeout
if (global_client->lc_epoch_pass_num > epoch_cnt) {
DEBUG("client_sig_timer: epoch pass num > epoch_cnt, terminate the conn");
lsp_client_close(global_client);
return;
}
if (global_client == NULL)
return;
// resend conn req or last data msg
lsp_client_resend_lastmsgbuf(global_client);
//Send an acknowledgment message for the most recently received data message, or an acknowledgment with sequence number 0 if no data messages have been received.
lsp_ack(global_client->lc_connid, global_client->lc_server_seqnum,
global_client->lc_socket, &global_client->lc_server_addr);
}
// Set length of epoch (in seconds)
void lsp_client_set_epoch_lth(double lth) {
epoch_lth = lth;
memset(&timer_client, 0, sizeof(struct itimerval));
timer_client.it_interval.tv_sec = epoch_lth;
timer_client.it_value.tv_sec = epoch_lth;
signal(SIGALRM, client_sig_timer);
signal(SIGALRM, client_sig_timer);
setitimer(ITIMER_REAL, &timer_client, NULL);
}
// Set number of epochs before timing out
void lsp_client_set_epoch_cnt(int cnt) {
epoch_cnt = cnt;
}
// client API
lsp_client* lsp_client_create(const char* dest, int port) {
lsp_client* client = NULL;
struct sockaddr_in* server_addr;
struct sockaddr_in* client_addr;
int addr_len = sizeof(struct sockaddr);
int addr_in_len = sizeof(struct sockaddr_in);
uint8_t* req_buf;
uint8_t ack_buf[MAXDATASIZE];
int req_len, ack_len, ack_ret;
LSPMessage req_msg = LSPMESSAGE__INIT;
LSPMessage* ack_msg;
uint32_t ack_connid;
uint32_t ack_seqnum;
int create_ret = 0;
client = (lsp_client*)malloc(sizeof(lsp_client));
if (client == NULL) {
PRINTF("lsp_client_create: malloc client failed\n");
return client;
}
// sig timer
global_client = client;
lsp_client_set_epoch_lth(epoch_lth);
// set is_last_msg_ack
client->lc_is_last_msg_ack = 1;
client->lc_socket = socket(AF_INET, SOCK_DGRAM, 0);
if (client->lc_socket < 0) {
PRINTF("lsp_client_create: create socket failed\n");
goto fail;
}
client_addr = &client->lc_client_addr;
memset(client_addr, 0, addr_in_len);
client_addr->sin_family = AF_INET;
client_addr->sin_addr.s_addr = htonl(INADDR_ANY);
client_addr->sin_port = htons(0);
// set SO_REUSEADDR so that we can re-use not fully deallocated chatrooms
int optval = 1;
setsockopt(client->lc_socket, SOL_SOCKET, SO_REUSEADDR, &optval, sizeof optval);
if (bind(client->lc_socket, (struct sockaddr *)client_addr, addr_in_len) < 0) {
PRINTF("lsp_client_create: bind failed\n");
goto fail;
}
server_addr = &client->lc_server_addr;
memset(server_addr, 0, sizeof(struct sockaddr));
server_addr->sin_family = AF_INET;
server_addr->sin_port = htons(port);
server_addr->sin_addr.s_addr = inet_addr(dest);
// send init msg
req_msg.connid = 0;
req_msg.seqnum = 0;
req_msg.payload.len = 0;
req_len = lspmessage__get_packed_size(&req_msg);
req_buf = malloc(req_len);
lspmessage__pack(&req_msg, req_buf);
DEBUG("lsp_client_create: send conn req\n");
lsp_client_store_lastmsgbuf(client, req_buf, req_len);
sendto_maydrop(client->lc_socket, req_buf, req_len, 0, (struct sockaddr *)server_addr, sizeof(struct sockaddr), false);
free(req_buf);
// receive init ack msg
DEBUG("lsp_client_create: wait ack");
ack_ret = recvfrom_maydrop(client->lc_socket, ack_buf, 4096, 0, (struct sockaddr *)&(client->lc_server_addr), &addr_len, false);
if (ack_ret == -1) {
DEBUG("lsp_client_create: receive init ack msg failed\n");
goto fail;
}
ack_msg = lspmessage__unpack(NULL, ack_ret, ack_buf);
ack_connid = ack_msg->connid;
ack_seqnum = ack_msg->seqnum;
DEBUG("lsp_client_create: ack connid %d ack_seqnum %d", ack_connid, ack_seqnum);
if (ack_connid != 0 && ack_seqnum == 0 && ack_msg->payload.len == 0) {
DEBUG("lsp_client_create: conn establish, connid %d\n", ack_connid);
client->lc_connid = ack_connid;
lsp_client_ack_lastmsgbuf(client);
create_ret = 1;
}
if (!create_ret) {
DEBUG("lsp_client_create: create_ret fail");
goto fail;
}
return client;
fail:
// todo: puzzle on fail create
// free(client);
// client = NULL;
return client;
}
bool lsp_client_store_lastmsgbuf(lsp_client* a_client, uint8_t* buf, int len) {
uint32_t old_seqnum = a_client->lc_client_seqnum;
if (a_client->lc_is_last_msg_ack == 0) {
DEBUG("lsp_client_store_lastmsgbuf: last msg not ack. abort");
DEBUG("lsp_client_store_lastmsgbuf: client seqnum %d", a_client->lc_client_seqnum);
exit(-1);
}
memcpy(a_client->lc_last_buf, buf, len);
a_client->lc_is_last_msg_ack = 0;
a_client->lc_last_buf_len = len;
}
void lsp_client_resend_lastmsgbuf(lsp_client* a_client) {
uint8_t* buf;
int len;
int addr_len = sizeof(struct sockaddr);
buf = a_client->lc_last_buf;
len = a_client->lc_last_buf_len;
if (a_client->lc_is_last_msg_ack == 1)
return;
DEBUG("lsp_client_resend_lastmsgbuf: connid %d client_seqnum %d, len %d",
a_client->lc_connid, a_client->lc_client_seqnum, len);
sendto_maydrop(a_client->lc_socket, buf, len, 0, (struct sockaddr*)&a_client->lc_server_addr, addr_len, false);
}
void lsp_client_ack_lastmsgbuf(lsp_client* a_client) {
if (a_client->lc_is_last_msg_ack == 0) {
a_client->lc_is_last_msg_ack = 1;
}
}
// Client Read. Return NULL when connection lost
// Returns number of bytes read
int lsp_client_read(lsp_client * a_client, uint8_t * pld) {
uint8_t buf[4096];
int len;
LSPMessage* msg;
int ret;
int addr_len = sizeof(struct sockaddr);
enum msg_type msg_type;
DEBUG("\n");
DEBUG("lsp_client_read:###################");
recv_again:
ret = recvfrom_maydrop(a_client->lc_socket, buf, 4096, 0, (struct sockaddr*)&(a_client->lc_server_addr), &addr_len, true);
if (ret == -1) {
DEBUG("lsp_client_read: recvfrom return -1\n");
return -1;
}
msg = lspmessage__unpack(NULL, ret, buf);
len = msg->payload.len;
msg_type = lsp_msg_type(msg);
if (msg_type != DATA_SEND) {
DEBUG("lsp_client_read: recv not DATA_SEND msg, try again");
dump_msg(msg);
goto recv_again;
}
if (msg->seqnum == a_client->lc_server_seqnum + 1 &&
msg->connid == a_client->lc_connid &&
msg->payload.len != 0) {
DEBUG("lsp_client_read: read server data, server_seqnum %d", msg->seqnum);
a_client->lc_server_seqnum = msg->seqnum;
a_client->lc_epoch_recv_flag = 1;
memcpy(pld, msg->payload.data, len);
lsp_msg_ack(msg, a_client->lc_socket, &a_client->lc_server_addr);
} else {
DEBUG("lsp_client_read: seqnum mismatch, sever_seqnum %d .dump msg\n", a_client->lc_server_seqnum);
dump_msg(msg);
}
lspmessage__free_unpacked(msg, NULL);
DEBUG("lsp_client_read:###################\n\n");
return len;
}
// Client Write. Should not send NULL
bool lsp_client_write(lsp_client* a_client, uint8_t* pld, int lth) {
uint8_t* req_buf = NULL;
int req_len, req_ret;
LSPMessage req_msg = LSPMESSAGE__INIT;
uint8_t ack_buf[MAXDATASIZE];
int ack_len, ack_ret;
LSPMessage* ack_msg;
int addr_len = sizeof(struct sockaddr);
enum msg_type msg_type;
int retry = 0;
DEBUG("\n");
DEBUG("lsp_client_write:###################");
// send data
req_msg.connid = a_client->lc_connid;
a_client->lc_client_seqnum++;
req_msg.seqnum = a_client->lc_client_seqnum;
req_msg.payload.data = malloc(sizeof(uint8_t) * lth);
if (req_msg.payload.data == NULL) {
PRINTF("lsp_client_write: alloc payload failed\n");
return -1;
}
req_msg.payload.len = lth;
memcpy(req_msg.payload.data, pld, lth * sizeof(uint8_t));
req_len = lspmessage__get_packed_size(&req_msg);
req_buf = malloc(req_len);
if (req_buf == NULL) {
PRINTF("lsp_client_write: alloc buf failed\n");
return -1;
}
lspmessage__pack(&req_msg, req_buf);
DEBUG("lsp_client_write: send msg connid %d, seqnum %d, buf %s", req_msg.connid, req_msg.seqnum, pld);
lsp_client_store_lastmsgbuf(a_client, req_buf, req_len);
req_ret = sendto_maydrop(a_client->lc_socket, req_buf, req_len, 0, (struct sockaddr *)&a_client->lc_server_addr, sizeof(struct sockaddr), true);
if (req_ret != req_len) {
DEBUG("lsp_client_write: sendto ret %d", req_ret);
}
free(req_buf);
free(req_msg.payload.data);
// receive ack
recv_ack:
retry++;
if (retry > 5)
goto out;
DEBUG("lsp_client_write: wait on ack");
ack_ret = recvfrom_maydrop(a_client->lc_socket, ack_buf, 4096, 0, (struct sockaddr *)&(a_client->lc_server_addr), &addr_len, false);
if (ack_ret == -1) {
DEBUG("lsp_client_create: receive init ack msg failed\n");
}
ack_msg = lspmessage__unpack(NULL, ack_ret, ack_buf);
msg_type = lsp_msg_type(ack_msg);
if (msg_type != DATA_ACK) {
DEBUG("lsp_client_write: recv not DATA_ACK, try again");
dump_msg(ack_msg);
goto recv_ack;
}
if (ack_msg->seqnum == a_client->lc_client_seqnum &&
ack_msg->connid == a_client->lc_connid &&
ack_msg->payload.len == 0) {
DEBUG("lsp_client_write: seqnum %d recv ack", a_client->lc_client_seqnum);
lsp_client_ack_lastmsgbuf(a_client);
} else {
DEBUG("lsp_client_write: wrong ack, send seqnum %d, recv %d", a_client->lc_client_seqnum, ack_msg->seqnum);
dump_msg(ack_msg);
DEBUG("lsp_ciient_write: try again");
memset(ack_buf, 0, MAXDATASIZE);
goto recv_ack;
}
out:
DEBUG("lsp_client_write:###################\n\n");
return true;
}
// Close connection. Remember to free memory.
bool lsp_client_close(lsp_client* a_client) {
close(a_client->lc_socket);
free(a_client);
a_client = NULL;
return true;
}
#endif