int link_read(struct link *link, char *data, size_t count, time_t stoptime)
{
ssize_t total = 0;
ssize_t chunk = 0;
if(count == 0)
return 0;
/* If this is a small read, attempt to fill the buffer */
if(count < BUFFER_SIZE) {
chunk = fill_buffer(link, stoptime);
if(chunk <= 0)
return chunk;
}
/* Then, satisfy the read from the buffer, if any. */
if(link->buffer_length > 0) {
chunk = MIN(link->buffer_length, count);
memcpy(data, &link->buffer[link->buffer_start], chunk);
data += chunk;
total += chunk;
count -= chunk;
link->buffer_start += chunk;
link->buffer_length -= chunk;
}
/* Otherwise, pull it all off the wire. */
while(count > 0) {
chunk = read(link->fd, data, count);
if(chunk < 0) {
if(errno_is_temporary(errno)) {
if(link_sleep(link, stoptime, 1, 0)) {
continue;
} else {
break;
}
} else {
break;
}
} else if(chunk == 0) {
break;
} else {
total += chunk;
count -= chunk;
data += chunk;
}
}
if(total > 0) {
return total;
} else {
if(chunk == 0) {
return 0;
} else {
return -1;
}
}
}
struct link *link_accept(struct link *master, time_t stoptime)
{
struct link *link = 0;
link = link_create();
if(!link)
goto failure;
while(1) {
if(!link_sleep(master, stoptime, 1, 0))
goto failure;
link->fd = accept(master->fd, 0, 0);
break;
}
if(!link_nonblocking(link, 1))
goto failure;
if(!link_address_remote(link, link->raddr, &link->rport))
goto failure;
link_squelch();
debug(D_TCP, "got connection from %s:%d", link->raddr, link->rport);
return link;
failure:
if(link)
link_close(link);
return 0;
}
static int fill_buffer(struct link *link, time_t stoptime)
{
int chunk;
if(link->buffer_length > 0)
return link->buffer_length;
while(1) {
chunk = read(link->fd, link->buffer, BUFFER_SIZE);
if(chunk > 0) {
link->buffer_start = 0;
link->buffer_length = chunk;
return chunk;
} else if(chunk == 0) {
link->buffer_start = 0;
link->buffer_length = 0;
return 0;
} else {
if(errno_is_temporary(errno)) {
if(link_sleep(link, stoptime, 1, 0)) {
continue;
} else {
return -1;
}
} else {
return -1;
}
}
}
}
static ssize_t fill_buffer(struct link *link, time_t stoptime)
{
if(link->buffer_length > 0)
return link->buffer_length;
while(1) {
ssize_t chunk = read(link->fd, link->buffer, sizeof(link->buffer));
if(chunk > 0) {
link->read += chunk;
link->buffer_start = link->buffer;
link->buffer_length = chunk;
return chunk;
} else if(chunk == 0) {
link->buffer_start = link->buffer;
link->buffer_length = 0;
return 0;
} else {
if(errno_is_temporary(errno)) {
if(link_sleep(link, stoptime, 1, 0)) {
continue;
} else {
return -1;
}
} else {
return -1;
}
}
}
}
ssize_t link_read_avail(struct link *link, char *data, size_t count, time_t stoptime)
{
ssize_t total = 0;
ssize_t chunk = 0;
/* First, satisfy anything from the buffer. */
if(link->buffer_length > 0) {
chunk = MIN(link->buffer_length, count);
memcpy(data, link->buffer_start, chunk);
data += chunk;
total += chunk;
count -= chunk;
link->buffer_start += chunk;
link->buffer_length -= chunk;
}
/* Next, read what is available off the wire */
while(count > 0) {
chunk = read(link->fd, data, count);
if(chunk < 0) {
/* ONLY BLOCK IF NOTHING HAS BEEN READ */
if(errno_is_temporary(errno) && total == 0) {
if(link_sleep(link, stoptime, 1, 0)) {
continue;
} else {
break;
}
} else {
break;
}
} else if(chunk == 0) {
break;
} else {
link->read += chunk;
total += chunk;
count -= chunk;
data += chunk;
}
}
if(total > 0) {
return total;
} else {
if(chunk == 0) {
return 0;
} else {
return -1;
}
}
}
ssize_t link_write(struct link *link, const char *data, size_t count, time_t stoptime)
{
ssize_t total = 0;
ssize_t chunk = 0;
if (!link)
return errno = EINVAL, -1;
while(count > 0) {
chunk = write(link->fd, data, count);
if(chunk < 0) {
if(errno_is_temporary(errno)) {
if(link_sleep(link, stoptime, 0, 1)) {
continue;
} else {
break;
}
} else {
break;
}
} else if(chunk == 0) {
break;
} else {
link->written += chunk;
total += chunk;
count -= chunk;
data += chunk;
}
}
if(total > 0) {
return total;
} else {
if(chunk == 0) {
return 0;
} else {
return -1;
}
}
}
struct link *link_connect(const char *addr, int port, time_t stoptime)
{
struct sockaddr_in address;
struct link *link = 0;
int result;
int save_errno;
link = link_create();
if(!link)
goto failure;
link_squelch();
memset(&address, 0, sizeof(address));
#if defined(CCTOOLS_OPSYS_DARWIN)
address.sin_len = sizeof(address);
#endif
address.sin_family = AF_INET;
address.sin_port = htons(port);
if(!string_to_ip_address(addr, (unsigned char *) &address.sin_addr))
goto failure;
link->fd = socket(AF_INET, SOCK_STREAM, 0);
if(link->fd < 0)
goto failure;
link_window_configure(link);
/* sadly, cygwin does not do non-blocking connect correctly */
#ifdef CCTOOLS_OPSYS_CYGWIN
if(!link_nonblocking(link, 0))
goto failure;
#else
if(!link_nonblocking(link, 1))
goto failure;
#endif
debug(D_TCP, "connecting to %s:%d", addr, port);
do {
result = connect(link->fd, (struct sockaddr *) &address, sizeof(address));
/* On some platforms, errno is not set correctly. */
/* If the remote address can be found, then we are really connected. */
/* Also, on bsd-derived systems, failure to connect is indicated by a second connect returning EINVAL. */
if(result < 0 && !errno_is_temporary(errno)) {
if(errno == EINVAL)
errno = ECONNREFUSED;
break;
}
if(link_address_remote(link, link->raddr, &link->rport)) {
debug(D_TCP, "made connection to %s:%d", link->raddr, link->rport);
#ifdef CCTOOLS_OPSYS_CYGWIN
link_nonblocking(link, 1);
#endif
return link;
}
} while(link_sleep(link, stoptime, 0, 1));
debug(D_TCP, "connection to %s:%d failed (%s)", addr, port, strerror(errno));
failure:
save_errno = errno;
if(link)
link_close(link);
errno = save_errno;
return 0;
}
struct link *link_connect(const char *addr, int port, time_t stoptime)
{
struct sockaddr_in address;
struct link *link = 0;
int result;
int save_errno;
link = link_create();
if(!link)
goto failure;
link_squelch();
memset(&address, 0, sizeof(address));
#if defined(CCTOOLS_OPSYS_DARWIN)
address.sin_len = sizeof(address);
#endif
address.sin_family = AF_INET;
address.sin_port = htons(port);
if(!string_to_ip_address(addr, (unsigned char *) &address.sin_addr))
goto failure;
link->fd = socket(AF_INET, SOCK_STREAM, 0);
if(link->fd < 0)
goto failure;
link_window_configure(link);
/* sadly, cygwin does not do non-blocking connect correctly */
#ifdef CCTOOLS_OPSYS_CYGWIN
if(!link_nonblocking(link, 0))
goto failure;
#else
if(!link_nonblocking(link, 1))
goto failure;
#endif
debug(D_TCP, "connecting to %s:%d", addr, port);
while(1) {
// First attempt a non-blocking connect
result = connect(link->fd, (struct sockaddr *) &address, sizeof(address));
// On many platforms, non-blocking connect sets errno in unexpected ways:
// On OSX, result=-1 and errno==EISCONN indicates a successful connection.
if(result<0 && errno==EISCONN) result=0;
// On BSD-derived systems, failure to connect is indicated by errno = EINVAL.
// Set it to something more explanatory.
if(result<0 && errno==EINVAL) errno=ECONNREFUSED;
// Otherwise, a non-temporary errno should cause us to bail out.
if(result<0 && !errno_is_temporary(errno)) break;
// If the remote address is valid, we are connected no matter what.
if(link_address_remote(link, link->raddr, &link->rport)) {
debug(D_TCP, "made connection to %s:%d", link->raddr, link->rport);
#ifdef CCTOOLS_OPSYS_CYGWIN
link_nonblocking(link, 1);
#endif
return link;
}
// if the time has expired, bail out
if( time(0) >= stoptime ) {
errno = ETIMEDOUT;
break;
}
// wait for some activity on the socket.
link_sleep(link, stoptime, 0, 1);
// No matter how the sleep ends, we want to go back to the top
// and call connect again to get a proper errno.
}
debug(D_TCP, "connection to %s:%d failed (%s)", addr, port, strerror(errno));
failure:
save_errno = errno;
if(link)
link_close(link);
errno = save_errno;
return 0;
}
