/**
* Closes the connection held by the PCB.
*
*/
err_t
tcp_close(struct tcp_pcb *pcb)
{
err_t err;
#if TCP_DEBUG
LWIP_DEBUGF(TCP_DEBUG, ("tcp_close: closing in state "));
tcp_debug_print_state(pcb->state);
LWIP_DEBUGF(TCP_DEBUG, ("\n"));
#endif /* TCP_DEBUG */
switch (pcb->state) {
case CLOSED:
/* Closing a pcb in the CLOSED state might seem erroneous,
* however, it is in this state once allocated and as yet unused
* and the user needs some way to free it should the need arise.
* Calling tcp_close() with a pcb that has already been closed, (i.e. twice)
* or for a pcb that has been used and then entered the CLOSED state
* is erroneous, but this should never happen as the pcb has in those cases
* been freed, and so any remaining handles are bogus. */
err = ERR_OK;
memp_free(MEMP_TCP_PCB, pcb);
pcb = NULL;
break;
case LISTEN:
err = ERR_OK;
tcp_pcb_remove((struct tcp_pcb **)&tcp_listen_pcbs.pcbs, pcb);
memp_free(MEMP_TCP_PCB_LISTEN, pcb);
pcb = NULL;
break;
case SYN_SENT:
err = ERR_OK;
tcp_pcb_remove(&tcp_active_pcbs, pcb);
memp_free(MEMP_TCP_PCB, pcb);
pcb = NULL;
break;
case SYN_RCVD:
case ESTABLISHED:
err = tcp_send_ctrl(pcb, TCP_FIN);
if (err == ERR_OK) {
pcb->state = FIN_WAIT_1;
}
break;
case CLOSE_WAIT:
err = tcp_send_ctrl(pcb, TCP_FIN);
if (err == ERR_OK) {
pcb->state = LAST_ACK;
}
break;
default:
/* Has already been closed, do nothing. */
err = ERR_OK;
pcb = NULL;
break;
}
if (pcb != NULL && err == ERR_OK) {
err = tcp_output(pcb);
}
return err;
}
static err_t
accept_function(void *arg, struct tcp_pcb *newpcb, err_t err)
{
sys_mbox_t mbox;
struct netconn *newconn;
struct netconn *conn;
#if API_MSG_DEBUG
#if TCP_DEBUG
tcp_debug_print_state(newpcb->state);
#endif /* TCP_DEBUG */
#endif /* API_MSG_DEBUG */
conn = (struct netconn *)arg;
mbox = conn->acceptmbox;
newconn = memp_malloc(MEMP_NETCONN);
if (newconn == NULL) {
return ERR_MEM;
}
newconn->recvmbox = sys_mbox_new();
if (newconn->recvmbox == SYS_MBOX_NULL) {
memp_free(MEMP_NETCONN, newconn);
return ERR_MEM;
}
newconn->mbox = sys_mbox_new();
if (newconn->mbox == SYS_MBOX_NULL) {
sys_mbox_free(newconn->recvmbox);
memp_free(MEMP_NETCONN, newconn);
return ERR_MEM;
}
newconn->sem = sys_sem_new(0);
if (newconn->sem == SYS_SEM_NULL) {
sys_mbox_free(newconn->recvmbox);
sys_mbox_free(newconn->mbox);
memp_free(MEMP_NETCONN, newconn);
return ERR_MEM;
}
/* Allocations were OK, setup the PCB etc */
newconn->type = NETCONN_TCP;
newconn->pcb.tcp = newpcb;
setup_tcp(newconn);
newconn->acceptmbox = SYS_MBOX_NULL;
newconn->err = err;
/* Register event with callback */
if (conn->callback)
{
(*conn->callback)(conn, NETCONN_EVT_RCVPLUS, 0);
}
/* We have to set the callback here even though
* the new socket is unknown. Mark the socket as -1. */
newconn->callback = conn->callback;
newconn->socket = -1;
newconn->recv_avail = 0;
sys_mbox_post(mbox, newconn);
return ERR_OK;
}
/*-----------------------------------------------------------------------------------*/
err_t
tcp_close(struct tcp_pcb *pcb)
{
err_t err;
#if TCP_DEBUG
DEBUGF(TCP_DEBUG, ("tcp_close: closing in state "));
tcp_debug_print_state(pcb->state);
DEBUGF(TCP_DEBUG, ("\n"));
#endif /* TCP_DEBUG */
switch(pcb->state) {
case LISTEN:
err = ERR_OK;
tcp_pcb_remove(TCP_LIST_LISTEN, pcb);
memp_free(MEMP_TCP_PCB_LISTEN, pcb);
pcb = NULL;
break;
case SYN_SENT:
err = ERR_OK;
tcp_pcb_remove(TCP_LIST_ACTIVE, pcb);
memp_free(MEMP_TCP_PCB, pcb);
pcb = NULL;
break;
case SYN_RCVD:
err = tcp_send_ctrl(pcb, TCP_FIN);
if(err == ERR_OK) {
pcb->state = FIN_WAIT_1;
}
break;
case ESTABLISHED:
err = tcp_send_ctrl(pcb, TCP_FIN);
if(err == ERR_OK) {
pcb->state = FIN_WAIT_1;
}
break;
case CLOSE_WAIT:
err = tcp_send_ctrl(pcb, TCP_FIN);
if(err == ERR_OK) {
pcb->state = LAST_ACK;
}
break;
default:
/* Has already been closed, do nothing. */
err = ERR_OK;
pcb = NULL;
break;
}
if(pcb != NULL && err == ERR_OK) {
err = tcp_output(pcb);
}
return err;
}
/**
* Closes the connection held by the PCB.
*
* Listening pcbs are freed and may not be referenced any more.
* Connection pcbs are freed if not yet connected and may not be referenced
* any more. If a connection is established (at least SYN received or in
* a closing state), the connection is closed, and put in a closing state.
* The pcb is then automatically freed in tcp_slowtmr(). It is therefore
* unsafe to reference it (unless an error is returned).
*
* @param pcb the tcp_pcb to close
* @return ERR_OK if connection has been closed
* another err_t if closing failed and pcb is not freed
*/
err_t
tcp_close(struct tcp_pcb *pcb)
{
#if TCP_DEBUG
LWIP_DEBUGF(TCP_DEBUG, ("tcp_close: closing in "));
tcp_debug_print_state(pcb->state);
#endif /* TCP_DEBUG */
if (pcb->state != LISTEN) {
/* Set a flag not to receive any more data... */
pcb->flags |= TF_RXCLOSED;
}
/* ... and close */
return tcp_close_shutdown(pcb, 1);
}
/**
* Closes the connection held by the PCB.
*
* Listening pcbs are freed and may not be referenced any more.
* Connection pcbs are freed if not yet connected and may not be referenced
* any more. If a connection is established (at least SYN received or in
* a closing state), the connection is closed, and put in a closing state.
* The pcb is then automatically freed in tcp_slowtmr(). It is therefore
* unsafe to reference it.
*
* @param pcb the tcp_pcb to close
* @return ERR_OK if connection has been closed
* another err_t if closing failed and pcb is not freed
*/
err_t
tcp_close(struct tcp_pcb *pcb)
{
err_t err;
#if TCP_DEBUG
LWIP_DEBUGF(TCP_DEBUG, ("tcp_close: closing in "));
tcp_debug_print_state(pcb->state);
#endif /* TCP_DEBUG */
switch (pcb->state) {
case CLOSED:
/* Closing a pcb in the CLOSED state might seem erroneous,
* however, it is in this state once allocated and as yet unused
* and the user needs some way to free it should the need arise.
* Calling tcp_close() with a pcb that has already been closed, (i.e. twice)
* or for a pcb that has been used and then entered the CLOSED state
* is erroneous, but this should never happen as the pcb has in those cases
* been freed, and so any remaining handles are bogus. */
err = ERR_OK;
TCP_RMV(&tcp_bound_pcbs, pcb);
memp_free(MEMP_TCP_PCB, pcb);
pcb = NULL;
break;
case LISTEN:
err = ERR_OK;
tcp_pcb_remove((struct tcp_pcb **)&tcp_listen_pcbs.pcbs, pcb);
memp_free(MEMP_TCP_PCB_LISTEN, pcb);
pcb = NULL;
break;
case SYN_SENT:
err = ERR_OK;
tcp_pcb_remove(&tcp_active_pcbs, pcb);
memp_free(MEMP_TCP_PCB, pcb);
pcb = NULL;
snmp_inc_tcpattemptfails();
break;
case SYN_RCVD:
err = tcp_send_ctrl(pcb, TCP_FIN);
if (err == ERR_OK) {
snmp_inc_tcpattemptfails();
pcb->state = FIN_WAIT_1;
}
break;
case ESTABLISHED:
err = tcp_send_ctrl(pcb, TCP_FIN);
if (err == ERR_OK) {
snmp_inc_tcpestabresets();
pcb->state = FIN_WAIT_1;
}
break;
case CLOSE_WAIT:
err = tcp_send_ctrl(pcb, TCP_FIN);
if (err == ERR_OK) {
snmp_inc_tcpestabresets();
pcb->state = LAST_ACK;
}
break;
default:
/* Has already been closed, do nothing. */
err = ERR_OK;
pcb = NULL;
break;
}
if (pcb != NULL && err == ERR_OK) {
/* To ensure all data has been sent when tcp_close returns, we have
to make sure tcp_output doesn't fail.
Since we don't really have to ensure all data has been sent when tcp_close
returns (unsent data is sent from tcp timer functions, also), we don't care
for the return value of tcp_output for now. */
/* @todo: When implementing SO_LINGER, this must be changed somehow:
If SOF_LINGER is set, the data should be sent when tcp_close returns. */
tcp_output(pcb);
}
return err;
}
/**
* The initial input processing of TCP. It verifies the TCP header, demultiplexes
* the segment between the PCBs and passes it on to tcp_process(), which implements
* the TCP finite state machine. This function is called by the IP layer (in
* ip_input()).
*
* @param p received TCP segment to process (p->payload pointing to the IP header)
* @param inp network interface on which this segment was received
*/
void
tcp_input(struct pbuf *p, struct netif *inp)
{
struct tcp_pcb *pcb, *prev;
struct tcp_pcb_listen *lpcb;
u8_t hdrlen;
err_t err;
PERF_START;
TCP_STATS_INC(tcp.recv);
snmp_inc_tcpinsegs();
iphdr = p->payload;
tcphdr = (struct tcp_hdr *)((u8_t *)p->payload + IPH_HL(iphdr) * 4);
#if TCP_INPUT_DEBUG
tcp_debug_print(tcphdr);
#endif
/* remove header from payload */
if (pbuf_header(p, -((s16_t)(IPH_HL(iphdr) * 4))) || (p->tot_len < sizeof(struct tcp_hdr))) {
/* drop short packets */
LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: short packet (%"U16_F" bytes) discarded\n", p->tot_len));
TCP_STATS_INC(tcp.lenerr);
TCP_STATS_INC(tcp.drop);
snmp_inc_tcpinerrs();
pbuf_free(p);
return;
}
/* Don't even process incoming broadcasts/multicasts. */
if (ip_addr_isbroadcast(&(iphdr->dest), inp) ||
ip_addr_ismulticast(&(iphdr->dest))) {
TCP_STATS_INC(tcp.proterr);
TCP_STATS_INC(tcp.drop);
snmp_inc_tcpinerrs();
pbuf_free(p);
return;
}
#if CHECKSUM_CHECK_TCP
/* Verify TCP checksum. */
if (inet_chksum_pseudo(p, (struct ip_addr *)&(iphdr->src),
(struct ip_addr *)&(iphdr->dest),
IP_PROTO_TCP, p->tot_len) != 0) {
LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: packet discarded due to failing checksum 0x%04"X16_F"\n",
inet_chksum_pseudo(p, (struct ip_addr *)&(iphdr->src), (struct ip_addr *)&(iphdr->dest),
IP_PROTO_TCP, p->tot_len)));
#if TCP_DEBUG
tcp_debug_print(tcphdr);
#endif /* TCP_DEBUG */
TCP_STATS_INC(tcp.chkerr);
TCP_STATS_INC(tcp.drop);
snmp_inc_tcpinerrs();
pbuf_free(p);
return;
}
#endif
/* Move the payload pointer in the pbuf so that it points to the
TCP data instead of the TCP header. */
hdrlen = TCPH_HDRLEN(tcphdr);
if(pbuf_header(p, -(hdrlen * 4))){
/* drop short packets */
LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: short packet\n"));
TCP_STATS_INC(tcp.lenerr);
TCP_STATS_INC(tcp.drop);
snmp_inc_tcpinerrs();
pbuf_free(p);
return;
}
/* Convert fields in TCP header to host byte order. */
tcphdr->src = ntohs(tcphdr->src);
tcphdr->dest = ntohs(tcphdr->dest);
seqno = tcphdr->seqno = ntohl(tcphdr->seqno);
ackno = tcphdr->ackno = ntohl(tcphdr->ackno);
tcphdr->wnd = ntohs(tcphdr->wnd);
flags = TCPH_FLAGS(tcphdr) & TCP_FLAGS;
tcplen = p->tot_len + ((flags & TCP_FIN || flags & TCP_SYN)? 1: 0);
/* Demultiplex an incoming segment. First, we check if it is destined
for an active connection. */
prev = NULL;
for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
LWIP_ASSERT("tcp_input: active pcb->state != CLOSED", pcb->state != CLOSED);
LWIP_ASSERT("tcp_input: active pcb->state != TIME-WAIT", pcb->state != TIME_WAIT);
LWIP_ASSERT("tcp_input: active pcb->state != LISTEN", pcb->state != LISTEN);
if (pcb->remote_port == tcphdr->src &&
pcb->local_port == tcphdr->dest &&
ip_addr_cmp(&(pcb->remote_ip), &(iphdr->src)) &&
ip_addr_cmp(&(pcb->local_ip), &(iphdr->dest))) {
/* Move this PCB to the front of the list so that subsequent
lookups will be faster (we exploit locality in TCP segment
arrivals). */
LWIP_ASSERT("tcp_input: pcb->next != pcb (before cache)", pcb->next != pcb);
if (prev != NULL) {
prev->next = pcb->next;
pcb->next = tcp_active_pcbs;
tcp_active_pcbs = pcb;
}
LWIP_ASSERT("tcp_input: pcb->next != pcb (after cache)", pcb->next != pcb);
break;
}
prev = pcb;
}
if (pcb == NULL) {
/* If it did not go to an active connection, we check the connections
in the TIME-WAIT state. */
for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
LWIP_ASSERT("tcp_input: TIME-WAIT pcb->state == TIME-WAIT", pcb->state == TIME_WAIT);
if (pcb->remote_port == tcphdr->src &&
pcb->local_port == tcphdr->dest &&
ip_addr_cmp(&(pcb->remote_ip), &(iphdr->src)) &&
ip_addr_cmp(&(pcb->local_ip), &(iphdr->dest))) {
/* We don't really care enough to move this PCB to the front
of the list since we are not very likely to receive that
many segments for connections in TIME-WAIT. */
LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: packed for TIME_WAITing connection.\n"));
tcp_timewait_input(pcb);
pbuf_free(p);
return;
}
}
/* Finally, if we still did not get a match, we check all PCBs that
are LISTENing for incoming connections. */
prev = NULL;
for(lpcb = tcp_listen_pcbs.listen_pcbs; lpcb != NULL; lpcb = lpcb->next) {
if ((ip_addr_isany(&(lpcb->local_ip)) ||
ip_addr_cmp(&(lpcb->local_ip), &(iphdr->dest))) &&
lpcb->local_port == tcphdr->dest) {
/* Move this PCB to the front of the list so that subsequent
lookups will be faster (we exploit locality in TCP segment
arrivals). */
if (prev != NULL) {
((struct tcp_pcb_listen *)prev)->next = lpcb->next;
/* our successor is the remainder of the listening list */
lpcb->next = tcp_listen_pcbs.listen_pcbs;
/* put this listening pcb at the head of the listening list */
tcp_listen_pcbs.listen_pcbs = lpcb;
}
LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: packed for LISTENing connection.\n"));
tcp_listen_input(lpcb);
pbuf_free(p);
return;
}
prev = (struct tcp_pcb *)lpcb;
}
}
#if TCP_INPUT_DEBUG
LWIP_DEBUGF(TCP_INPUT_DEBUG, ("+-+-+-+-+-+-+-+-+-+-+-+-+-+- tcp_input: flags "));
tcp_debug_print_flags(TCPH_FLAGS(tcphdr));
LWIP_DEBUGF(TCP_INPUT_DEBUG, ("-+-+-+-+-+-+-+-+-+-+-+-+-+-+\n"));
#endif /* TCP_INPUT_DEBUG */
if (pcb != NULL) {
/* The incoming segment belongs to a connection. */
#if TCP_INPUT_DEBUG
#if TCP_DEBUG
tcp_debug_print_state(pcb->state);
#endif /* TCP_DEBUG */
#endif /* TCP_INPUT_DEBUG */
/* Set up a tcp_seg structure. */
inseg.next = NULL;
inseg.len = p->tot_len;
inseg.dataptr = p->payload;
inseg.p = p;
inseg.tcphdr = tcphdr;
recv_data = NULL;
recv_flags = 0;
/* If there is data which was previously "refused" by upper layer */
if (pcb->refused_data != NULL) {
/* Notify again application with data previously received. */
LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: notify kept packet\n"));
TCP_EVENT_RECV(pcb, pcb->refused_data, ERR_OK, err);
if (err == ERR_OK) {
pcb->refused_data = NULL;
} else {
/* drop incoming packets, because pcb is "full" */
LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: drop incoming packets, because pcb is \"full\"\n"));
TCP_STATS_INC(tcp.drop);
snmp_inc_tcpinerrs();
pbuf_free(p);
return;
}
}
tcp_input_pcb = pcb;
err = tcp_process(pcb);
tcp_input_pcb = NULL;
/* A return value of ERR_ABRT means that tcp_abort() was called
and that the pcb has been freed. If so, we don't do anything. */
if (err != ERR_ABRT) {
if (recv_flags & TF_RESET) {
/* TF_RESET means that the connection was reset by the other
end. We then call the error callback to inform the
application that the connection is dead before we
deallocate the PCB. */
TCP_EVENT_ERR(pcb->errf, pcb->callback_arg, ERR_RST);
tcp_pcb_remove(&tcp_active_pcbs, pcb);
memp_free(MEMP_TCP_PCB, pcb);
} else if (recv_flags & TF_CLOSED) {
/* The connection has been closed and we will deallocate the
PCB. */
tcp_pcb_remove(&tcp_active_pcbs, pcb);
memp_free(MEMP_TCP_PCB, pcb);
} else {
err = ERR_OK;
/* If the application has registered a "sent" function to be
called when new send buffer space is available, we call it
now. */
if (pcb->acked > 0) {
TCP_EVENT_SENT(pcb, pcb->acked, err);
}
if (recv_data != NULL) {
if(flags & TCP_PSH) {
recv_data->flags |= PBUF_FLAG_PUSH;
}
/* Notify application that data has been received. */
TCP_EVENT_RECV(pcb, recv_data, ERR_OK, err);
/* If the upper layer can't receive this data, store it */
if (err != ERR_OK) {
pcb->refused_data = recv_data;
LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: keep incoming packet, because pcb is \"full\"\n"));
}
}
/* If a FIN segment was received, we call the callback
function with a NULL buffer to indicate EOF. */
if (recv_flags & TF_GOT_FIN) {
TCP_EVENT_RECV(pcb, NULL, ERR_OK, err);
}
/* If there were no errors, we try to send something out. */
if (err == ERR_OK) {
tcp_output(pcb);
}
}
}
/* give up our reference to inseg.p */
if (inseg.p != NULL)
{
pbuf_free(inseg.p);
inseg.p = NULL;
}
#if TCP_INPUT_DEBUG
#if TCP_DEBUG
tcp_debug_print_state(pcb->state);
#endif /* TCP_DEBUG */
#endif /* TCP_INPUT_DEBUG */
} else {
/* If no matching PCB was found, send a TCP RST (reset) to the
sender. */
LWIP_DEBUGF(TCP_RST_DEBUG, ("tcp_input: no PCB match found, resetting.\n"));
if (!(TCPH_FLAGS(tcphdr) & TCP_RST)) {
TCP_STATS_INC(tcp.proterr);
TCP_STATS_INC(tcp.drop);
tcp_rst(ackno, seqno + tcplen,
&(iphdr->dest), &(iphdr->src),
tcphdr->dest, tcphdr->src);
}
pbuf_free(p);
}
LWIP_ASSERT("tcp_input: tcp_pcbs_sane()", tcp_pcbs_sane());
PERF_STOP("tcp_input");
}
/**
* Closes the connection held by the PCB.
*
* Listening pcbs are freed and may not be referenced any more.
* Connection pcbs are freed if not yet connected and may not be referenced
* any more. If a connection is established (at least SYN received or in
* a closing state), the connection is closed, and put in a closing state.
* The pcb is then automatically freed in tcp_slowtmr(). It is therefore
* unsafe to reference it.
*
* @param pcb the tcp_pcb to close
* @return ERR_OK if connection has been closed
* another err_t if closing failed and pcb is not freed
*/
err_t
tcp_close(struct tcp_pcb *pcb)
{
err_t err;
#if TCP_DEBUG
LWIP_DEBUGF(TCP_DEBUG, ("tcp_close: closing in "));
tcp_debug_print_state(pcb->state);
#endif /* TCP_DEBUG */
switch (pcb->state) {
/* 若TCP在CLOSE状态，即tcp_new()之后从未使用过 */
case CLOSED:
/* Closing a pcb in the CLOSED state might seem erroneous,
* however, it is in this state once allocated and as yet unused
* and the user needs some way to free it should the need arise.
* Calling tcp_close() with a pcb that has already been closed, (i.e. twice)
* or for a pcb that has been used and then entered the CLOSED state
* is erroneous, but this should never happen as the pcb has in those cases
* been freed, and so any remaining handles are bogus. */
err = ERR_OK;
/* 从tcp_bound_pcbs链表上删除(如果已经调用tcp_bind()的话) */
TCP_RMV(&tcp_bound_pcbs, pcb);
/* 释放TCP控制所占内存 */
memp_free(MEMP_TCP_PCB, pcb);
pcb = NULL;
break;
case LISTEN:
err = ERR_OK;
/* 从LISTEN链表上删除，并发送可能存在的delayed ACKs */
tcp_pcb_remove((struct tcp_pcb **)&tcp_listen_pcbs.pcbs, pcb);
/* 释放LISTEN类型的TCP控制块 */
memp_free(MEMP_TCP_PCB_LISTEN, pcb);
pcb = NULL;
break;
case SYN_SENT:
err = ERR_OK;
tcp_pcb_remove(&tcp_active_pcbs, pcb);
memp_free(MEMP_TCP_PCB, pcb);
pcb = NULL;
snmp_inc_tcpattemptfails();
break;
case SYN_RCVD:
/* 构造FIN报文，主动关闭 */
err = tcp_send_ctrl(pcb, TCP_FIN);
if (err == ERR_OK) {
snmp_inc_tcpattemptfails();
/* 进入FIN_WAIT_1状态 */
pcb->state = FIN_WAIT_1;
}
break;
case ESTABLISHED:
/* 构造FIN报文，主动关闭 */
err = tcp_send_ctrl(pcb, TCP_FIN);
if (err == ERR_OK) {
snmp_inc_tcpestabresets();
/* 进入FIN_WAIT_1状态 */
pcb->state = FIN_WAIT_1;
}
break;
/* 被动关闭，收到对方的FIN后，构造FIN关闭另一个方向传输 */
case CLOSE_WAIT:
err = tcp_send_ctrl(pcb, TCP_FIN);
if (err == ERR_OK) {
snmp_inc_tcpestabresets();
/* 进入LAST_ACK状态 */
pcb->state = LAST_ACK;
}
break;
/* 其他状态，用TCP定时器函数实现 */
default:
/* Has already been closed, do nothing. */
err = ERR_OK;
pcb = NULL;
break;
}
/* 发送TCP控制块中剩余的报文段，包括FIN报文 */
if (pcb != NULL && err == ERR_OK) {
/* To ensure all data has been sent when tcp_close returns, we have
to make sure tcp_output doesn't fail.
Since we don't really have to ensure all data has been sent when tcp_close
returns (unsent data is sent from tcp timer functions, also), we don't care
for the return value of tcp_output for now. */
/* @todo: When implementing SO_LINGER, this must be changed somehow:
If SOF_LINGER is set, the data should be sent when tcp_close returns. */
tcp_output(pcb);
}
return err;
}
/**
* Receive callback function for RAW netconns.
* Doesn't 'eat' the packet, only references it and sends it to
* conn->recvmbox
*
* @see raw.h (struct raw_pcb.recv) for parameters and return value
*/
static u8_t
recv_raw(void *arg, struct raw_pcb *pcb, struct pbuf *p,
struct ip_addr *addr)
{
struct pbuf *q;
struct netbuf *buf;
struct netconn *conn;
#if LWIP_SO_RCVBUF
int recv_avail;
#endif /* LWIP_SO_RCVBUF */
LWIP_UNUSED_ARG(addr);
conn = arg;
#if LWIP_SO_RCVBUF
SYS_ARCH_GET(conn->recv_avail, recv_avail);
if ((conn != NULL) && (conn->recvmbox != SYS_MBOX_NULL) &&
((recv_avail + (int)(p->tot_len)) <= conn->recv_bufsize)) {
#else /* LWIP_SO_RCVBUF */
if ((conn != NULL) && (conn->recvmbox != SYS_MBOX_NULL)) {
#endif /* LWIP_SO_RCVBUF */
/* copy the whole packet into new pbufs */
q = pbuf_alloc(PBUF_RAW, p->tot_len, PBUF_RAM);
if(q != NULL) {
if (pbuf_copy(q, p) != ERR_OK) {
pbuf_free(q);
q = NULL;
}
}
if(q != NULL) {
buf = memp_malloc(MEMP_NETBUF);
if (buf == NULL) {
pbuf_free(q);
return 0;
}
buf->p = q;
buf->ptr = q;
buf->addr = &(((struct ip_hdr*)(q->payload))->src);
buf->port = pcb->protocol;
if (sys_mbox_trypost(conn->recvmbox, buf) != ERR_OK) {
netbuf_delete(buf);
return 0;
} else {
SYS_ARCH_INC(conn->recv_avail, q->tot_len);
/* Register event with callback */
API_EVENT(conn, NETCONN_EVT_RCVPLUS, q->tot_len);
}
}
}
return 0; /* do not eat the packet */
}
#endif /* LWIP_RAW*/
#if LWIP_UDP
/**
* Receive callback function for UDP netconns.
* Posts the packet to conn->recvmbox or deletes it on memory error.
*
* @see udp.h (struct udp_pcb.recv) for parameters
*/
static void
recv_udp(void *arg, struct udp_pcb *pcb, struct pbuf *p,
struct ip_addr *addr, u16_t port)
{
struct netbuf *buf;
struct netconn *conn;
#if LWIP_SO_RCVBUF
int recv_avail;
#endif /* LWIP_SO_RCVBUF */
LWIP_UNUSED_ARG(pcb); /* only used for asserts... */
LWIP_ASSERT("recv_udp must have a pcb argument", pcb != NULL);
LWIP_ASSERT("recv_udp must have an argument", arg != NULL);
conn = arg;
LWIP_ASSERT("recv_udp: recv for wrong pcb!", conn->pcb.udp == pcb);
#if LWIP_SO_RCVBUF
SYS_ARCH_GET(conn->recv_avail, recv_avail);
if ((conn == NULL) || (conn->recvmbox == SYS_MBOX_NULL) ||
((recv_avail + (int)(p->tot_len)) > conn->recv_bufsize)) {
#else /* LWIP_SO_RCVBUF */
if ((conn == NULL) || (conn->recvmbox == SYS_MBOX_NULL)) {
#endif /* LWIP_SO_RCVBUF */
pbuf_free(p);
return;
}
buf = memp_malloc(MEMP_NETBUF);
if (buf == NULL) {
pbuf_free(p);
return;
} else {
buf->p = p;
buf->ptr = p;
buf->addr = addr;
buf->port = port;
#if LWIP_NETBUF_RECVINFO
{
const struct ip_hdr* iphdr = ip_current_header();
/* get the UDP header - always in the first pbuf, ensured by udp_input */
const struct udp_hdr* udphdr = (void*)(((char*)iphdr) + IPH_LEN(iphdr));
buf->toaddr = (struct ip_addr*)&iphdr->dest;
buf->toport = udphdr->dest;
}
#endif /* LWIP_NETBUF_RECVINFO */
}
if (sys_mbox_trypost(conn->recvmbox, buf) != ERR_OK) {
netbuf_delete(buf);
return;
} else {
SYS_ARCH_INC(conn->recv_avail, p->tot_len);
/* Register event with callback */
API_EVENT(conn, NETCONN_EVT_RCVPLUS, p->tot_len);
}
}
#endif /* LWIP_UDP */
#if LWIP_TCP
/**
* Receive callback function for TCP netconns.
* Posts the packet to conn->recvmbox, but doesn't delete it on errors.
*
* @see tcp.h (struct tcp_pcb.recv) for parameters and return value
*/
static err_t
recv_tcp(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err)
{
struct netconn *conn;
u16_t len;
LWIP_UNUSED_ARG(pcb);
LWIP_ASSERT("recv_tcp must have a pcb argument", pcb != NULL);
LWIP_ASSERT("recv_tcp must have an argument", arg != NULL);
conn = arg;
LWIP_ASSERT("recv_tcp: recv for wrong pcb!", conn->pcb.tcp == pcb);
if ((conn == NULL) || (conn->recvmbox == SYS_MBOX_NULL)) {
return ERR_VAL;
}
conn->err = err;
if (p != NULL) {
len = p->tot_len;
SYS_ARCH_INC(conn->recv_avail, len);
} else {
len = 0;
}
if (sys_mbox_trypost(conn->recvmbox, p) != ERR_OK) {
return ERR_MEM;
} else {
/* Register event with callback */
API_EVENT(conn, NETCONN_EVT_RCVPLUS, len);
}
return ERR_OK;
}
/**
* Poll callback function for TCP netconns.
* Wakes up an application thread that waits for a connection to close
* or data to be sent. The application thread then takes the
* appropriate action to go on.
*
* Signals the conn->sem.
* netconn_close waits for conn->sem if closing failed.
*
* @see tcp.h (struct tcp_pcb.poll) for parameters and return value
*/
static err_t
poll_tcp(void *arg, struct tcp_pcb *pcb)
{
struct netconn *conn = arg;
LWIP_UNUSED_ARG(pcb);
LWIP_ASSERT("conn != NULL", (conn != NULL));
if (conn->state == NETCONN_WRITE) {
do_writemore(conn);
} else if (conn->state == NETCONN_CLOSE) {
do_close_internal(conn);
}
return ERR_OK;
}
/**
* Sent callback function for TCP netconns.
* Signals the conn->sem and calls API_EVENT.
* netconn_write waits for conn->sem if send buffer is low.
*
* @see tcp.h (struct tcp_pcb.sent) for parameters and return value
*/
static err_t
sent_tcp(void *arg, struct tcp_pcb *pcb, u16_t len)
{
struct netconn *conn = arg;
LWIP_UNUSED_ARG(pcb);
LWIP_ASSERT("conn != NULL", (conn != NULL));
if (conn->state == NETCONN_WRITE) {
LWIP_ASSERT("conn->pcb.tcp != NULL", conn->pcb.tcp != NULL);
do_writemore(conn);
} else if (conn->state == NETCONN_CLOSE) {
do_close_internal(conn);
}
if (conn) {
if ((conn->pcb.tcp != NULL) && (tcp_sndbuf(conn->pcb.tcp) > TCP_SNDLOWAT)) {
API_EVENT(conn, NETCONN_EVT_SENDPLUS, len);
}
}
return ERR_OK;
}
/**
* Error callback function for TCP netconns.
* Signals conn->sem, posts to all conn mboxes and calls API_EVENT.
* The application thread has then to decide what to do.
*
* @see tcp.h (struct tcp_pcb.err) for parameters
*/
static void
err_tcp(void *arg, err_t err)
{
struct netconn *conn;
conn = arg;
LWIP_ASSERT("conn != NULL", (conn != NULL));
conn->pcb.tcp = NULL;
conn->err = err;
if (conn->recvmbox != SYS_MBOX_NULL) {
/* Register event with callback */
API_EVENT(conn, NETCONN_EVT_RCVPLUS, 0);
sys_mbox_post(conn->recvmbox, NULL);
}
if (conn->op_completed != SYS_SEM_NULL && conn->state == NETCONN_CONNECT) {
conn->state = NETCONN_NONE;
sys_sem_signal(conn->op_completed);
}
if (conn->acceptmbox != SYS_MBOX_NULL) {
/* Register event with callback */
API_EVENT(conn, NETCONN_EVT_RCVPLUS, 0);
sys_mbox_post(conn->acceptmbox, NULL);
}
if ((conn->state == NETCONN_WRITE) || (conn->state == NETCONN_CLOSE)) {
/* calling do_writemore/do_close_internal is not necessary
since the pcb has already been deleted! */
conn->state = NETCONN_NONE;
/* wake up the waiting task */
sys_sem_signal(conn->op_completed);
}
}
/**
* Setup a tcp_pcb with the correct callback function pointers
* and their arguments.
*
* @param conn the TCP netconn to setup
*/
static void
setup_tcp(struct netconn *conn)
{
struct tcp_pcb *pcb;
pcb = conn->pcb.tcp;
tcp_arg(pcb, conn);
tcp_recv(pcb, recv_tcp);
tcp_sent(pcb, sent_tcp);
tcp_poll(pcb, poll_tcp, 4);
tcp_err(pcb, err_tcp);
}
/**
* Accept callback function for TCP netconns.
* Allocates a new netconn and posts that to conn->acceptmbox.
*
* @see tcp.h (struct tcp_pcb_listen.accept) for parameters and return value
*/
static err_t
accept_function(void *arg, struct tcp_pcb *newpcb, err_t err)
{
struct netconn *newconn;
struct netconn *conn;
#if API_MSG_DEBUG
#if TCP_DEBUG
tcp_debug_print_state(newpcb->state);
#endif /* TCP_DEBUG */
#endif /* API_MSG_DEBUG */
conn = (struct netconn *)arg;
LWIP_ERROR("accept_function: invalid conn->acceptmbox",
conn->acceptmbox != SYS_MBOX_NULL, return ERR_VAL;);
/* We have to set the callback here even though
* the new socket is unknown. conn->socket is marked as -1. */
newconn = netconn_alloc(conn->type, conn->callback);
if (newconn == NULL) {
return ERR_MEM;
}
newconn->pcb.tcp = newpcb;
setup_tcp(newconn);
newconn->err = err;
if (sys_mbox_trypost(conn->acceptmbox, newconn) != ERR_OK) {
/* When returning != ERR_OK, the connection is aborted in tcp_process(),
so do nothing here! */
newconn->pcb.tcp = NULL;
netconn_free(newconn);
return ERR_MEM;
} else {
/* Register event with callback */
API_EVENT(conn, NETCONN_EVT_RCVPLUS, 0);
}
return ERR_OK;
}
#endif /* LWIP_TCP */
/**
* Create a new pcb of a specific type.
* Called from do_newconn().
*
* @param msg the api_msg_msg describing the connection type
* @return msg->conn->err, but the return value is currently ignored
*/
static err_t
pcb_new(struct api_msg_msg *msg)
{
msg->conn->err = ERR_OK;
LWIP_ASSERT("pcb_new: pcb already allocated", msg->conn->pcb.tcp == NULL);
/* Allocate a PCB for this connection */
switch(NETCONNTYPE_GROUP(msg->conn->type)) {
#if LWIP_RAW
case NETCONN_RAW:
msg->conn->pcb.raw = raw_new(msg->msg.n.proto);
if(msg->conn->pcb.raw == NULL) {
msg->conn->err = ERR_MEM;
break;
}
raw_recv(msg->conn->pcb.raw, recv_raw, msg->conn);
break;
#endif /* LWIP_RAW */
#if LWIP_UDP
case NETCONN_UDP:
msg->conn->pcb.udp = udp_new();
if(msg->conn->pcb.udp == NULL) {
msg->conn->err = ERR_MEM;
break;
}
#if LWIP_UDPLITE
if (msg->conn->type==NETCONN_UDPLITE) {
udp_setflags(msg->conn->pcb.udp, UDP_FLAGS_UDPLITE);
}
#endif /* LWIP_UDPLITE */
if (msg->conn->type==NETCONN_UDPNOCHKSUM) {
udp_setflags(msg->conn->pcb.udp, UDP_FLAGS_NOCHKSUM);
}
udp_recv(msg->conn->pcb.udp, recv_udp, msg->conn);
break;
#endif /* LWIP_UDP */
#if LWIP_TCP
case NETCONN_TCP:
msg->conn->pcb.tcp = tcp_new();
if(msg->conn->pcb.tcp == NULL) {
msg->conn->err = ERR_MEM;
break;
}
setup_tcp(msg->conn);
break;
#endif /* LWIP_TCP */
default:
/* Unsupported netconn type, e.g. protocol disabled */
msg->conn->err = ERR_VAL;
break;
}
return msg->conn->err;
}
