/*
* socket.c -- Socket support module for UNIX
*
* Copyright (c) Go Ahead, 1995-1999
*/
/******************************** Description *********************************/
/*
* SCO Unix Socket Module. This supports non-blocking buffered socket I/O.
*/
/********************************** Includes **********************************/
#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#if __rtems__
#include <sys/select.h>
#endif
#include "uemf.h"
/*********************************** Defines **********************************/
typedef struct {
char host[64]; /* Host name */
ringq_t inBuf; /* Input ring queue */
ringq_t outBuf; /* Output ring queue */
ringq_t lineBuf; /* Line ring queue */
socketAccept_t accept; /* Accept handler */
socketHandler_t handler; /* User I/O handler */
int handler_data; /* User handler data */
int sid; /* Index into socket[] */
int port; /* Port to listen on */
int flags; /* Current state flags */
int readyMask; /* Events now ready */
int interestMask; /* Events interest */
int error; /* Last error */
int sock; /* Actual socket handle */
} socket_t;
/************************************ Locals **********************************/
static socket_t** socketList; /* List of open sockets */
static int socketMax; /* Maximum size of socket */
static int socketHighestFd = -1; /* Highest socket fd opened */
/***************************** Forward Declarations ***************************/
static int socketAlloc(char* host, int port, socketAccept_t accept, int flags);
static void socketFree(int sid);
static void socketAccept(socket_t* sp);
static int socketGetInput(int sid, char* buf, int toRead, int* errCode);
static int socketDoOutput(socket_t* sp, char* buf, int toWrite, int* errCode);
static int socketDoEvent(socket_t *sp);
static int socketGetError();
static int socketWaitForEvent(socket_t* sp, int events, int* errCode);
static int socketNonBlock(socket_t *sp);
static socket_t* socketPtr(int sid);
/*********************************** Code *************************************/
/*
* Open socket module
*/
int socketOpen()
{
return 0;
}
/******************************************************************************/
/*
* Close the socket module, by closing all open connections
*/
void socketClose()
{
int i;
for (i = socketMax; i >= 0; i--) {
if (socketList && socketList[i]) {
socketCloseConnection(i);
}
}
}
/******************************************************************************/
/*
* Open a client or server socket. Host is NULL if we want server capability.
*/
int socketOpenConnection(char* host, int port, socketAccept_t accept, int flags)
{
socket_t *sp;
struct sockaddr_in sockaddr;
struct hostent *hostent; /* Host database entry */
int sid, rc;
/*
* Allocate a socket structure
*/
if ((sid = socketAlloc(host, port, accept, flags)) < 0) {
return -1;
}
sp = socketList[sid];
a_assert(sp);
/*
* Create the socket address structure
*/
memset((char *) &sockaddr, '\0', sizeof(struct sockaddr_in));
sockaddr.sin_family = AF_INET;
sockaddr.sin_port = htons((short) (port & 0xFFFF));
if (host == NULL) {
sockaddr.sin_addr.s_addr = INADDR_ANY;
} else {
sockaddr.sin_addr.s_addr = inet_addr(host);
if (sockaddr.sin_addr.s_addr == INADDR_NONE) {
hostent = gethostbyname(host);
if (hostent != NULL) {
memcpy((char *) &sockaddr.sin_addr,
(char *) hostent->h_addr_list[0],
(size_t) hostent->h_length);
} else {
errno = ENXIO;
socketFree(sid);
return -1;
}
}
}
/*
* Create the socket. Set the close on exec flag so children don't
* inherit the socket.
*/
sp->sock = socket(AF_INET, SOCK_STREAM, 0);
if (sp->sock < 0) {
socketFree(sid);
return -1;
}
fcntl(sp->sock, F_SETFD, FD_CLOEXEC);
socketHighestFd = max(socketHighestFd, sp->sock);
/*
* Host is set if we are the client
*/
if (host) {
/*
* Connect to the remote server
*/
if (connect(sp->sock, (struct sockaddr *) &sockaddr,
sizeof(sockaddr)) < 0) {
socketFree(sid);
return -1;
}
socketNonBlock(sp);
} else {
/*
* Bind to the socket endpoint with resule and the call listen()
** to start listening
*/
rc = 1;
setsockopt(sp->sock, SOL_SOCKET, SO_REUSEADDR, (char *)&rc, sizeof(rc));
if (bind(sp->sock, (struct sockaddr *) &sockaddr, sizeof(sockaddr))
< 0) {
socketFree(sid);
return -1;
}
sp->flags |= SOCKET_LISTENING;
if (listen(sp->sock, SOMAXCONN) < 0) {
socketFree(sid);
return -1;
}
sp->interestMask = SOCKET_READABLE;
}
return sid;
}
/******************************************************************************/
/*
* Close a socket
*/
void socketCloseConnection(int sid)
{
socket_t* sp;
if ((sp = socketPtr(sid)) == NULL) {
return;
}
/*
* We always flush all output before closing. Unlink from the emf event
* mechanism and then free (and close) the connection
*/
socketFlush(sid, 1);
socketFree(sid);
}
/******************************************************************************/
/*
* Accept a connection. Called by socketDoEvent
*/
static void socketAccept(socket_t* sp)
{
struct sockaddr_in addr;
socket_t *nsp;
int len;
int newSock, nid;
a_assert(sp);
/*
* Accept the connection and prevent inheriting by children (F_SETFD)
*/
len = sizeof(struct sockaddr_in);
if ((newSock = accept(sp->sock, (struct sockaddr *) &addr, &len)) < 0) {
return;
}
fcntl(newSock, F_SETFD, FD_CLOEXEC);
socketHighestFd = max(socketHighestFd, newSock);
/*
* Create a socket structure and insert into the socket list
*/
nid = socketAlloc(sp->host, sp->port, sp->accept, 0);
nsp = socketList[nid];
a_assert(nsp);
nsp->sock = newSock;
if (nsp == NULL) {
return;
}
/*
* Call the user accept callback, the user must call socketCreateHandler
* to register for further events of interest.
*/
if (sp->accept != NULL) {
if ((sp->accept)(nid, inet_ntoa(addr.sin_addr),
ntohs(addr.sin_port)) < 0) {
socketFree(nid);
return;
}
}
socketNonBlock(nsp);
}
/******************************************************************************/
/*
* Write to a socket. This may block if the underlying socket cannot
* absorb the data. Returns -1 on error, otherwise the number of bytes
* written.
*/
int socketWrite(int sid, char* buf, int bufsize)
{
socket_t* sp;
ringq_t* rq;
int len, bytesWritten, room;
a_assert(buf);
a_assert(bufsize >= 0);
if ((sp = socketPtr(sid)) == NULL) {
return -1;
}
/*
* Loop adding as much data to the output ringq as we can absorb
* Flush when the ringq is too full and continue.
*/
rq = &sp->outBuf;
for (bytesWritten = 0; bufsize > 0; ) {
if ((room = ringqPutBlkMax(rq)) == 0) {
if (socketFlush(sid, 0) < 0) {
return -1;
}
if ((room = ringqPutBlkMax(rq)) == 0) {
break;
}
continue;
}
len = min(room, bufsize);
ringqPutBlk(rq, (unsigned char*) buf, len);
bytesWritten += len;
bufsize -= len;
buf += len;
}
return bytesWritten;
}
/******************************************************************************/
/*
* Read from a socket. Return the number of bytes read if successful. This
* may be less than the requested "bufsize" and may be zero. Return -1 for
* errors. Return 0 for EOF. Otherwise return the number of bytes read. Since
* this may be zero, callers should use socketEof() to distinguish between
* this and EOF. Note: this ignores the line buffer, so a previous socketGets
* which read a partial line may cause a subsequent socketRead to miss
* some data.
*/
int socketRead(int sid, char* buf, int bufsize)
{
socket_t* sp;
ringq_t* rq;
int len, room, errCode, bytesRead;
a_assert(buf);
a_assert(bufsize > 0);
if ((sp = socketPtr(sid)) == NULL) {
return -1;
}
if (sp->flags & SOCKET_EOF) {
return 0;
}
rq = &sp->inBuf;
for (bytesRead = 0; bufsize > 0; ) {
len = min(ringqLen(rq), bufsize);
if (len <= 0) {
room = ringqPutBlkMax(rq);
len = socketGetInput(sid, (char*) rq->endp, room, &errCode);
if (len < 0) {
if (errCode == EWOULDBLOCK) {
if (bytesRead >= 0) {
return bytesRead;
}
}
return -1;
} else if (len == 0) {
/*
* This is EOF, but we may have already read some data so pass that
* back first before notifying EOF. The next read will return 0
* to indicate EOF.
*/
return bytesRead;
}
ringqPutBlkAdj(rq, len);
len = min(len, bufsize);
}
memcpy(&buf[bytesRead], rq->servp, len);
ringqGetBlkAdj(rq, len);
bufsize -= len;
bytesRead += len;
}
return bytesRead;
}
/******************************************************************************/
/*
* Get a string from a socket. This returns data in *buf in a malloced string
* after trimming the '\n'. If there is zero bytes returned, *buf will be set
* to NULL. It returns -1 for error, EOF or when no complete line yet read.
* Otherwise the length of the line is returned. If a partial line is read
* socketInputBuffered or socketEof can be used to distinguish between EOF
* and partial line still buffered. This routine eats and ignores carriage
* returns.
*/
int socketGets(int sid, char** buf)
{
socket_t* sp;
ringq_t* lq;
char c;
int rc, len;
a_assert(buf);
if ((sp = socketPtr(sid)) == NULL) {
return -1;
}
lq = &sp->lineBuf;
while (1) {
if ((rc = socketRead(sid, &c, 1)) < 0) {
return rc;
} else if (rc == 0) {
/*
* If there is a partial line and we are at EOF, pretend we saw a '\n'
*/
if (ringqLen(lq) > 0 && (sp->flags & SOCKET_EOF)) {
c = '\n';
} else {
return -1;
}
}
/*
* If a newline is seen, return the data excluding the new line to the
* caller. If carriage return is seen, just eat it.
*/
if (c == '\n') {
len = ringqLen(lq);
if (len > 0) {
if ((*buf = balloc(B_L, len + 1)) == NULL) {
return -1;
}
memset(*buf, 0, len + 1);
ringqGetBlk(lq, (unsigned char*) *buf, len);
} else {
*buf = NULL;
}
return len;
} else if (c == '\r') {
continue;
}
ringqPutc(lq, c);
}
}
/******************************************************************************/
/*
* Flush a socket. Do not wait, just initiate output and return.
* This will return -1 on errors and 0 if successful.
*/
int socketFlush(int sid, int block)
{
socket_t* sp;
ringq_t* rq;
int len, bytesWritten, errCode;
a_assert(block == 0 || block == 1);
if ((sp = socketPtr(sid)) == NULL) {
return -1;
}
rq = &sp->outBuf;
/*
* Set the background flushing flag which socketDoEvent will check to
* continue the flush.
*/
if (!block) {
sp->flags |= SOCKET_FLUSHING;
}
/*
* Break from loop if not blocking after initiating output. If we are blocking
* we wait for a write event.
*/
while (ringqLen(rq) > 0) {
len = ringqGetBlkMax(&sp->outBuf);
bytesWritten = socketDoOutput(sp, (char*) rq->servp, len, &errCode);
if (bytesWritten < 0) {
if (errCode == EINTR) {
continue;
} else if (errCode == EWOULDBLOCK || errCode == EAGAIN) {
if (! block) {
return 0;
}
if (socketWaitForEvent(sp, SOCKET_WRITABLE | SOCKET_EXCEPTION,
&errCode)) {
continue;
}
}
return -1;
}
ringqGetBlkAdj(rq, bytesWritten);
if (! block) {
break;
}
}
return 0;
}
/******************************************************************************/
/*
* Return the count of input characters buffered. We look at both the line
* buffer and the input (raw) buffer. Return -1 on error or EOF.
*/
int socketInputBuffered(int sid)
{
socket_t* sp;
if ((sp = socketPtr(sid)) == NULL) {
return -1;
}
if (socketEof(sid)) {
return -1;
}
return ringqLen(&sp->lineBuf) + ringqLen(&sp->inBuf);
}
/******************************************************************************/
/*
* Return true if EOF
*/
int socketEof(int sid)
{
socket_t* sp;
if ((sp = socketPtr(sid)) == NULL) {
return -1;
}
return sp->flags & SOCKET_EOF;
}
/******************************************************************************/
/*
* Create a user handler for this socket. The handler called whenever there
* is an event of interest as defined by interestMask (SOCKET_READABLE, ...)
*/
void socketCreateHandler(int sid, int interestMask, socketHandler_t handler,
int data)
{
socket_t* sp;
if ((sp = socketPtr(sid)) == NULL) {
return;
}
sp->handler = handler;
sp->handler_data = data;
sp->interestMask = interestMask;
}
/******************************************************************************/
/*
* Delete a handler
*/
void socketDeleteHandler(int sid)
{
socket_t* sp;
if ((sp = socketPtr(sid)) == NULL) {
return;
}
sp->handler = NULL;
sp->interestMask = 0;
}
/******************************************************************************/
/*
* Get more input from the socket and return in buf.
* Returns 0 for EOF, -1 for errors and otherwise the number of bytes read.
*/
static int socketGetInput(int sid, char* buf, int toRead, int* errCode)
{
struct sockaddr_in server;
socket_t* sp;
int len, bytesRead;
a_assert(buf);
a_assert(errCode);
*errCode = 0;
if ((sp = socketPtr(sid)) == NULL) {
return -1;
}
/*
* If we have previously seen an EOF condition, then just return
*/
if (sp->flags & SOCKET_EOF) {
return 0;
}
/*
* Read the data
*/
if (sp->flags & SOCKET_BROADCAST) {
server.sin_family = AF_INET;
server.sin_addr.s_addr = INADDR_BROADCAST;
server.sin_port = htons((short)(sp->port & 0xFFFF));
len = sizeof(server);
bytesRead = recvfrom(sp->sock, buf, toRead, 0,
(struct sockaddr*) &server, &len);
} else {
bytesRead = recv(sp->sock, buf, toRead, 0);
}
if (bytesRead < 0) {
if (errno == ECONNRESET) {
return 0;
}
*errCode = socketGetError();
return -1;
} else if (bytesRead == 0) {
sp->flags |= SOCKET_EOF;
}
return bytesRead;
}
/******************************************************************************/
/*
* Socket output procedure. Return -1 on errors otherwise return the number
* of bytes written.
*/
static int socketDoOutput(socket_t* sp, char* buf, int toWrite, int* errCode)
{
struct sockaddr_in server;
int bytes;
a_assert(sp);
a_assert(buf);
a_assert(toWrite > 0);
a_assert(errCode);
*errCode = 0;
/*
* Write the data
*/
if (sp->flags & SOCKET_BROADCAST) {
server.sin_family = AF_INET;
server.sin_addr.s_addr = INADDR_BROADCAST;
server.sin_port = htons((short)(sp->port & 0xFFFF));
bytes = sendto(sp->sock, buf, toWrite, 0,
(struct sockaddr*) &server, sizeof(server));
} else {
bytes = send(sp->sock, buf, toWrite, 0);
}
if (bytes == 0 && bytes != toWrite) {
*errCode = EWOULDBLOCK;
return -1;
}
if (bytes < 0) {
*errCode = socketGetError();
}
return bytes;
}
/******************************************************************************/
/*
* Return TRUE if there is a socket with an event ready to process,
*/
int socketReady()
{
socket_t *sp;
int i;
for (i = 0; i < socketMax; i++) {
if ((sp = socketList[i]) == NULL) {
continue;
}
if (sp->readyMask & sp->interestMask) {
return 1;
}
}
return 0;
}
/******************************************************************************/
/*
* Wait for a handle to become readable or writable and return a number of
* noticed events.
*/
int socketSelect()
{
socket_t *sp;
fd_mask *readFds, *writeFds, *exceptFds;
int sid, len, nwords, index, bit, nEvents;
/*
* Allocate and zero the select masks
*/
nwords = (socketHighestFd + NFDBITS - 1) / NFDBITS;
len = nwords * sizeof(int);
readFds = balloc(B_L, len);
memset(readFds, 0, len);
writeFds = balloc(B_L, len);
memset(writeFds, 0, len);
exceptFds = balloc(B_L, len);
memset(exceptFds, 0, len);
/*
* Set the select event masks for events to watch
*/
for (sid = 0; sid < socketMax; sid++) {
if ((sp = socketList[sid]) == NULL) {
continue;
}
a_assert(sp);
/*
* Initialize the ready masks and compute the mask offsets.
*/
index = sp->sock / (NBBY * sizeof(fd_mask));
bit = 1 << (sp->sock % (NBBY * sizeof(fd_mask)));
/*
* Set the appropriate bit in the ready masks for the sp->sock.
*/
if (sp->interestMask & SOCKET_READABLE) {
readFds[index] |= bit;
}
if (sp->interestMask & SOCKET_WRITABLE) {
writeFds[index] |= bit;
}
if (sp->interestMask & SOCKET_EXCEPTION) {
exceptFds[index] |= bit;
}
}
/*
* Wait for the event or a timeout.
*/
nEvents = select(socketHighestFd + 1, (fd_set *) readFds,
(fd_set *) writeFds, (fd_set *) exceptFds, NULL);
if (nEvents > 0) {
for (sid = 0; sid < socketMax; sid++) {
if ((sp = socketList[sid]) == NULL) {
continue;
}
index = sp->sock / (NBBY * sizeof(fd_mask));
bit = 1 << (sp->sock % (NBBY * sizeof(fd_mask)));
if (readFds[index] & bit) {
sp->readyMask |= SOCKET_READABLE;
}
if (writeFds[index] & bit) {
sp->readyMask |= SOCKET_WRITABLE;
}
if (exceptFds[index] & bit) {
sp->readyMask |= SOCKET_EXCEPTION;
}
}
}
bfree(B_L, readFds);
bfree(B_L, writeFds);
bfree(B_L, exceptFds);
return nEvents;
}
/******************************************************************************/
/*
* Process socket events
*/
void socketProcess()
{
socket_t *sp;
int sid;
/*
* Process each socket
*/
for (sid = 0; sid < socketMax; sid++) {
if ((sp = socketList[sid]) == NULL) {
continue;
}
if ((sp->readyMask & sp->interestMask) ||
((sp->interestMask & SOCKET_READABLE) &&
socketInputBuffered(sid))) {
socketDoEvent(sp);
}
}
}
/******************************************************************************/
/*
* Process and event on the event queue
*/
static int socketDoEvent(socket_t *sp)
{
ringq_t* rq;
int sid;
a_assert(sp);
sid = sp->sid;
if (sp->readyMask & SOCKET_READABLE) {
if (sp->flags & SOCKET_LISTENING) {
socketAccept(sp);
sp->readyMask = 0;
return 1;
}
} else {
/*
* If there is still read data in the buffers, trigger the read handler
* NOTE: this may busy spin if the read handler doesn't read the data
*/
if (sp->interestMask & SOCKET_READABLE && socketInputBuffered(sid)) {
sp->readyMask |= SOCKET_READABLE;
}
}
/*
* If now writable and flushing in the background, continue flushing
*/
if (sp->readyMask & SOCKET_WRITABLE) {
if (sp->flags & SOCKET_FLUSHING) {
rq = &sp->outBuf;
if (ringqLen(rq) > 0) {
socketFlush(sp->sid, 0);
} else {
sp->flags &= ~SOCKET_FLUSHING;
}
}
}
/*
* Now invoke the users socket handler. NOTE: the handler may delete the
* socket, so we must be very careful after calling the handler.
*/
if (sp->handler && (sp->interestMask & sp->readyMask)) {
(sp->handler)(sid, sp->interestMask & sp->readyMask,
sp->handler_data);
/*
* Make sure socket pointer is still valid, then set the readyMask
* to 0.
*/
if (socketPtr(sid)) {
sp->readyMask = 0;
}
}
return 1;
}
/******************************************************************************/
/*
* Allocate a new socket structure
*/
static int socketAlloc(char* host, int port, socketAccept_t accept, int flags)
{
socket_t *sp;
int sid;
if ((sid = hAlloc((void***) &socketList)) < 0) {
return -1;
}
if ((sp = (socket_t*) balloc(B_L, sizeof(socket_t))) == NULL) {
hFree((void***) &socket, sid);
return -1;
}
memset(sp, 0, sizeof(socket_t));
socketList[sid] = sp;
if (sid >= socketMax)
socketMax = sid + 1;
sp->sid = sid;
sp->accept = accept;
sp->port = port;
sp->flags = flags;
if (host) {
strncpy(sp->host, host, sizeof(sp->host));
}
ringqOpen(&sp->inBuf, SOCKET_BUFSIZ, SOCKET_BUFSIZ);
ringqOpen(&sp->outBuf, SOCKET_BUFSIZ, SOCKET_BUFSIZ);
ringqOpen(&sp->lineBuf, SOCKET_BUFSIZ, -1);
return sid;
}
/******************************************************************************/
/*
* Free a socket structure
*/
static void socketFree(int sid)
{
socket_t* sp;
int i;
if ((sp = socketPtr(sid)) == NULL) {
return;
}
if (sp->sock >= 0) {
close(sp->sock);
}
ringqClose(&sp->inBuf);
ringqClose(&sp->outBuf);
ringqClose(&sp->lineBuf);
bfree(B_L, sp);
socketMax = hFree((void***) &socketList, sid);
/*
* Calculate the new highest socket number
*/
socketHighestFd = -1;
for (i = 0; i < socketMax; i++) {
if ((sp = socketList[i]) == NULL) {
continue;
}
socketHighestFd = max(socketHighestFd, sp->sock);
}
}
/******************************************************************************/
/*
* Validate a socket handle
*/
static socket_t* socketPtr(int sid)
{
if (sid < 0 || sid >= socketMax || socketList[sid] == NULL) {
a_assert(NULL);
return NULL;
}
a_assert(socketList[sid]);
return socketList[sid];
}
/******************************************************************************/
/*
* Get the operating system error code
*/
static int socketGetError()
{
return errno;
}
/******************************************************************************/
/*
* Wait until an event occurs on a socket. Return 1 on success, 0 on failure.
*/
static int socketWaitForEvent(socket_t* sp, int interestMask, int* errCode)
{
a_assert(sp);
while (socketSelect()) {
if (sp->readyMask & interestMask) {
break;
}
}
if (sp->readyMask & SOCKET_EXCEPTION) {
return -1;
} else if (sp->readyMask & SOCKET_WRITABLE) {
return 0;
} else {
*errCode = errno = EWOULDBLOCK;
return -1;
}
}
/******************************************************************************/
/*
* Put the socket into non-blocking mode
*/
static int socketNonBlock(socket_t *sp)
{
int flags;
flags = fcntl(sp->sock, F_GETFL) | O_NONBLOCK;
if (fcntl(sp->sock, F_SETFL, flags) < 0) {
return -1;
}
return 0;
}
/******************************************************************************/
/*
* Duplicate stdin and stdout
*/
int DuplicateStdFile (int sid)
{
if (0 != dup2(socketList[sid]->sock, 0) || 1 != dup2(socketList[sid]->sock, 1))
return -1;
return 0;
}