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mysock_api.c
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mysock_api.c
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/* mysock_api.c--application interface to the mysocket layer */
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include "mysock.h"
#include "mysock_impl.h"
#include "network_io.h"
#include "connection_demux.h"
/* MYSOCK_CHECK(cond,rc) checks that 'cond' is true; if it isn't, error
* 'rc' is indicated to the caller.
*/
#define MYSOCK_ERROR_EXIT(rc) { errno = rc; return -1; }
#define MYSOCK_CHECK(cond,rc) { if (!(cond)) MYSOCK_ERROR_EXIT(rc); }
/* create a new mysocket; returns the corresponding mysocket descriptor */
mysocket_t mysocket()
{
return _mysock_new_mysocket();
}
/* simply a wrapper around bind() */
int mybind(mysocket_t sd, struct sockaddr *addr, int addrlen)
{
mysock_context_t *ctx = _mysock_get_context(sd);
assert(addr);
MYSOCK_CHECK(ctx != NULL, EBADF);
MYSOCK_CHECK(addr->sa_family == AF_INET, EADDRNOTAVAIL);
/* mybind() must precede mylisten() */
assert(!ctx->listening);
ctx->bound = TRUE;
ctx->network_state.local_addr = *addr;
return _network_bind(&ctx->network_state, addr, addrlen);
}
/* connect to the address specified in name on the mysocket sd */
int myconnect(mysocket_t sd, struct sockaddr *name, int namelen)
{
mysock_context_t *ctx = _mysock_get_context(sd);
MYSOCK_CHECK(ctx != NULL, EINVAL);
MYSOCK_CHECK((ctx->network_state.peer_addr_len == 0), EISCONN);
#ifdef DEBUG
struct sockaddr_in *sin = (struct sockaddr_in *) name;
fprintf(stderr, "\n####Initiating a new connection to %s:%u#### (sd=%d)\n",
inet_ntoa(sin->sin_addr), ntohs(sin->sin_port), sd);
fflush(stderr);
#endif /*DEBUG*/
ctx->network_state.peer_addr = *name;
ctx->network_state.peer_addr_len = namelen;
ctx->network_state.peer_addr_valid = TRUE;
/* record connection setup for demultiplexing */
if (!ctx->bound)
{
int rc;
/* we need to find the local port number to set up demultiplexing
* before we send the SYN. (this is really only required in the VNS
* case--we have to demultiplex only on listening sockets for the
* UDP/TCP network layer--but it doesn't do any harm here in
* general).
*/
if ((rc = _mysock_bind_ephemeral(ctx)) < 0)
return rc;
}
/* time for kick off */
_mysock_transport_init(sd, TRUE);
/* block until connection is established, or we hit an error */
return _mysock_wait_for_connection(ctx);
}
mysocket_t myaccept(mysocket_t sd, struct sockaddr *addr, int *addrlen)
{
mysock_context_t *accept_ctx = _mysock_get_context(sd);
mysock_context_t *ctx;
MYSOCK_CHECK(accept_ctx != NULL, EBADF);
MYSOCK_CHECK(accept_ctx->listening, EINVAL);
#ifdef DEBUG
fprintf(stderr, "\n####Accepting a new connection at port# %hu#### "
"(sd=%d)\n",
ntohs(_network_get_port(&accept_ctx->network_state)), sd);
fflush(stderr);
#endif /*DEBUG*/
/* the new socket is created on an incoming SYN. block here until we
* establish a connection, or STCP indicates an error condition.
*/
_mysock_dequeue_connection(accept_ctx, &ctx);
assert(ctx);
if (!ctx->stcp_errno)
{
/* fill in addr, addrlen with address of peer */
assert(ctx->network_state.peer_addr_len > 0);
if (addr && addrlen)
{
*addr = ctx->network_state.peer_addr;
*addrlen = ctx->network_state.peer_addr_len;
}
}
assert(ctx->listen_sd == sd);
DEBUG_LOG(("***myaccept(%d) returning new sd %d***\n", sd, ctx->my_sd));
return (errno = ctx->stcp_errno) ? -1 : ctx->my_sd;
}
/* in this implementation, mylisten() is assumed to follow mybind() */
int mylisten(mysocket_t sd, int backlog)
{
mysock_context_t *ctx = _mysock_get_context(sd);
assert(ctx->bound);
MYSOCK_CHECK(ctx != NULL, EBADF);
MYSOCK_CHECK(ctx->bound, EINVAL);
/* set up the socket for demultiplexing */
ctx->listening = TRUE;
_mysock_set_backlog(ctx, backlog);
if (_network_listen(&ctx->network_state, backlog) < 0)
return -1;
/* since we don't spawn an STCP worker thread for passive sockets
* (there's no transport layer related work to do, so
* _mysock_transport_init() is never called for such sockets), we
* begin receiving network packets here...
*/
if (_network_start_recv_thread(ctx) < 0)
{
assert(0);
return -1;
}
return 0;
}
/* close the given mysocket. note that the semantics of myclose() differ
* slightly from a regular close(); STCP doesn't implement TIME_WAIT, so
* myclose() simply discards all knowledge of the connection once the
* connection is terminated.
*/
int myclose(mysocket_t sd)
{
mysock_context_t *ctx = _mysock_get_context(sd);
DEBUG_LOG(("***myclose(%d)***\n", sd));
MYSOCK_CHECK(ctx != NULL, EBADF);
/* stcp_wait_for_event() needs to wake up on a socket close request */
PTHREAD_CALL(pthread_mutex_lock(&ctx->data_ready_lock));
ctx->close_requested = TRUE;
PTHREAD_CALL(pthread_mutex_unlock(&ctx->data_ready_lock));
PTHREAD_CALL(pthread_cond_broadcast(&ctx->data_ready_cond));
/* block until STCP thread exits */
if (ctx->transport_thread_started)
{
assert(!ctx->listening);
assert(ctx->is_active || ctx->listen_sd != -1);
PTHREAD_CALL(pthread_join(ctx->transport_thread, NULL));
ctx->transport_thread_started = FALSE;
}
_network_stop_recv_thread(ctx);
if (ctx->listening)
{
/* remove entry from SYN demultiplexing table */
_mysock_close_passive_socket(ctx);
}
/* free all resources associated with this mysocket */
_mysock_free_context(ctx);
DEBUG_LOG(("myclose(%d) returning...\n", sd));
return 0;
}
int mywrite(mysocket_t sd, const void *buf, size_t buf_len)
{
mysock_context_t *ctx = _mysock_get_context(sd);
MYSOCK_CHECK(ctx != NULL, EBADF);
MYSOCK_CHECK(!ctx->listening, EINVAL);
assert(!ctx->close_requested);
_mysock_enqueue_buffer(ctx, &ctx->app_recv_queue, buf, buf_len);
/* XXX: all bytes are queued, irrespective of current sender window */
return buf_len;
}
int myread(mysocket_t sd, void *buf, size_t buf_len)
{
mysock_context_t *ctx = _mysock_get_context(sd);
int len;
MYSOCK_CHECK(ctx != NULL, EBADF);
MYSOCK_CHECK(!ctx->listening, EINVAL);
assert(!ctx->close_requested);
if (ctx->eof)
return 0;
if ((len = _mysock_dequeue_buffer(ctx, &ctx->app_send_queue,
buf, buf_len, TRUE)) == 0)
{
/* make sure repeated calls to myread() return 0 on EOF */
ctx->eof = TRUE;
}
return len;
}
/* fills in addr with current port associated with the mysocket descriptor.
* like the regular getsockname(), this does not fill in the local IP
* address unless it's known.
*/
int mygetsockname(mysocket_t sd, struct sockaddr *addr, socklen_t *addrlen)
{
mysock_context_t *ctx = _mysock_get_context(sd);
assert(addr && addrlen);
MYSOCK_CHECK(ctx != NULL, EBADF);
MYSOCK_CHECK(addr != NULL && addrlen != NULL, EFAULT);
*addr = ctx->network_state.local_addr;
assert(!addr->sa_family || addr->sa_family == AF_INET);
addr->sa_family = AF_INET;
((struct sockaddr_in *) addr)->sin_port =
_network_get_port(&ctx->network_state);
if (ctx->network_state.peer_addr_valid)
{
/* XXX: if local address has been bound, and local_addr is set,
* we probably shouldn't override it here... although this
* shouldn't really affect anything...
*/
((struct sockaddr_in *) addr)->sin_addr.s_addr =
_network_get_local_addr(&ctx->network_state);
}
return 0;
}
int mygetpeername(mysocket_t sd, struct sockaddr *name, socklen_t *namelen)
{
mysock_context_t *ctx = _mysock_get_context(sd);
assert(name && namelen);
MYSOCK_CHECK(name != NULL && namelen != NULL, EFAULT);
memcpy(name, &ctx->network_state.peer_addr,
MIN(*namelen, (socklen_t)ctx->network_state.peer_addr_len));
MYSOCK_CHECK((*namelen = ctx->network_state.peer_addr_len) > 0, ENOTCONN);
return 0;
}
/* returns IP address of interface on which packets to/from network address
* peer_addr (network byte order) are delivered.
*/
uint32_t mylocalip(uint32_t peer_addr)
{
return _network_get_interface_ip(peer_addr);
}