/*
* os_unix.c --
*
* Description of file.
*
*
* Copyright (c) 1995 Open Market, Inc.
* All rights reserved.
*
* This file contains proprietary and confidential information and
* remains the unpublished property of Open Market, Inc. Use,
* disclosure, or reproduction is prohibited except as permitted by
* express written license agreement with Open Market, Inc.
*
* Bill Snapper
* snapper@openmarket.com
*/
#ifndef lint
static const char rcsid[] = "$Id: os_unix.c,v 1.37 2002/03/05 19:14:49 robs Exp $";
#endif /* not lint */
#include "fcgi_config.h"
#include <sys/types.h>
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#include <arpa/inet.h>
#include <assert.h>
#include <errno.h>
#include <fcntl.h> /* for fcntl */
#include <math.h>
#include <memory.h> /* for memchr() */
#include <netinet/tcp.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <sys/un.h>
#include <signal.h>
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h> /* for getpeername */
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include "fastcgi.h"
#include "fcgimisc.h"
#include "fcgios.h"
#ifndef INADDR_NONE
#define INADDR_NONE ((unsigned long) -1)
#endif
/*
* This structure holds an entry for each oustanding async I/O operation.
*/
typedef struct {
OS_AsyncProc procPtr; /* callout completion procedure */
ClientData clientData; /* caller private data */
int fd;
int len;
int offset;
void *buf;
int inUse;
} AioInfo;
/*
* Entries in the async I/O table are allocated 2 per file descriptor.
*
* Read Entry Index = fd * 2
* Write Entry Index = (fd * 2) + 1
*/
#define AIO_RD_IX(fd) (fd * 2)
#define AIO_WR_IX(fd) ((fd * 2) + 1)
static int asyncIoInUse = FALSE;
static int asyncIoTableSize = 16;
static AioInfo *asyncIoTable = NULL;
static int libInitialized = FALSE;
static fd_set readFdSet;
static fd_set writeFdSet;
static fd_set readFdSetPost;
static int numRdPosted = 0;
static fd_set writeFdSetPost;
static int numWrPosted = 0;
static int volatile maxFd = -1;
static int shutdownPending = FALSE;
static int shutdownNow = FALSE;
void OS_ShutdownPending()
{
shutdownPending = TRUE;
}
static void OS_Sigusr1Handler(int signo)
{
OS_ShutdownPending();
}
static void OS_SigpipeHandler(int signo)
{
;
}
static void installSignalHandler(int signo, const struct sigaction * act, int force)
{
struct sigaction sa;
sigaction(signo, NULL, &sa);
if (force || sa.sa_handler == SIG_DFL)
{
sigaction(signo, act, NULL);
}
}
static void OS_InstallSignalHandlers(int force)
{
struct sigaction sa;
sigemptyset(&sa.sa_mask);
sa.sa_flags = 0;
sa.sa_handler = OS_SigpipeHandler;
installSignalHandler(SIGPIPE, &sa, force);
sa.sa_handler = OS_Sigusr1Handler;
installSignalHandler(SIGUSR1, &sa, force);
}
/*
*--------------------------------------------------------------
*
* OS_LibInit --
*
* Set up the OS library for use.
*
* NOTE: This function is really only needed for application
* asynchronous I/O. It will most likely change in the
* future to setup the multi-threaded environment.
*
* Results:
* Returns 0 if success, -1 if not.
*
* Side effects:
* Async I/O table allocated and initialized.
*
*--------------------------------------------------------------
*/
int OS_LibInit(int stdioFds[3])
{
if(libInitialized)
return 0;
asyncIoTable = (AioInfo *)malloc(asyncIoTableSize * sizeof(AioInfo));
if(asyncIoTable == NULL) {
errno = ENOMEM;
return -1;
}
memset((char *) asyncIoTable, 0,
asyncIoTableSize * sizeof(AioInfo));
FD_ZERO(&readFdSet);
FD_ZERO(&writeFdSet);
FD_ZERO(&readFdSetPost);
FD_ZERO(&writeFdSetPost);
OS_InstallSignalHandlers(FALSE);
libInitialized = TRUE;
return 0;
}
/*
*--------------------------------------------------------------
*
* OS_LibShutdown --
*
* Shutdown the OS library.
*
* Results:
* None.
*
* Side effects:
* Memory freed, fds closed.
*
*--------------------------------------------------------------
*/
void OS_LibShutdown()
{
if(!libInitialized)
return;
free(asyncIoTable);
asyncIoTable = NULL;
libInitialized = FALSE;
return;
}
/*
*----------------------------------------------------------------------
*
* OS_BuildSockAddrUn --
*
* Using the pathname bindPath, fill in the sockaddr_un structure
* *servAddrPtr and the length of this structure *servAddrLen.
*
* The format of the sockaddr_un structure changed incompatibly in
* 4.3BSD Reno. Digital UNIX supports both formats, other systems
* support one or the other.
*
* Results:
* 0 for normal return, -1 for failure (bindPath too long).
*
*----------------------------------------------------------------------
*/
static int OS_BuildSockAddrUn(const char *bindPath,
struct sockaddr_un *servAddrPtr,
int *servAddrLen)
{
int bindPathLen = strlen(bindPath);
#ifdef HAVE_SOCKADDR_UN_SUN_LEN /* 4.3BSD Reno and later: BSDI, DEC */
if(bindPathLen >= sizeof(servAddrPtr->sun_path)) {
return -1;
}
#else /* 4.3 BSD Tahoe: Solaris, HPUX, DEC, ... */
if(bindPathLen > sizeof(servAddrPtr->sun_path)) {
return -1;
}
#endif
memset((char *) servAddrPtr, 0, sizeof(*servAddrPtr));
servAddrPtr->sun_family = AF_UNIX;
memcpy(servAddrPtr->sun_path, bindPath, bindPathLen);
#ifdef HAVE_SOCKADDR_UN_SUN_LEN /* 4.3BSD Reno and later: BSDI, DEC */
*servAddrLen = sizeof(servAddrPtr->sun_len)
+ sizeof(servAddrPtr->sun_family)
+ bindPathLen + 1;
servAddrPtr->sun_len = *servAddrLen;
#else /* 4.3 BSD Tahoe: Solaris, HPUX, DEC, ... */
*servAddrLen = sizeof(servAddrPtr->sun_family) + bindPathLen;
#endif
return 0;
}
union SockAddrUnion {
struct sockaddr_un unixVariant;
struct sockaddr_in inetVariant;
};
/*
* OS_CreateLocalIpcFd --
*
* This procedure is responsible for creating the listener socket
* on Unix for local process communication. It will create a
* domain socket or a TCP/IP socket bound to "localhost" and return
* a file descriptor to it to the caller.
*
* Results:
* Listener socket created. This call returns either a valid
* file descriptor or -1 on error.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
int OS_CreateLocalIpcFd(const char *bindPath, int backlog)
{
int listenSock, servLen;
union SockAddrUnion sa;
int tcp = FALSE;
unsigned long tcp_ia = 0;
char *tp;
short port = 0;
char host[MAXPATHLEN];
strcpy(host, bindPath);
if((tp = strchr(host, ':')) != 0) {
*tp++ = 0;
if((port = atoi(tp)) == 0) {
*--tp = ':';
} else {
tcp = TRUE;
}
}
if(tcp) {
if (!*host || !strcmp(host,"*")) {
tcp_ia = htonl(INADDR_ANY);
} else {
tcp_ia = inet_addr(host);
if (tcp_ia == INADDR_NONE) {
struct hostent * hep;
hep = gethostbyname(host);
if ((!hep) || (hep->h_addrtype != AF_INET || !hep->h_addr_list[0])) {
fprintf(stderr, "Cannot resolve host name %s -- exiting!\n", host);
exit(1);
}
if (hep->h_addr_list[1]) {
fprintf(stderr, "Host %s has multiple addresses ---\n", host);
fprintf(stderr, "you must choose one explicitly!!!\n");
exit(1);
}
tcp_ia = ((struct in_addr *) (hep->h_addr))->s_addr;
}
}
}
if(tcp) {
listenSock = socket(AF_INET, SOCK_STREAM, 0);
if(listenSock >= 0) {
int flag = 1;
if(setsockopt(listenSock, SOL_SOCKET, SO_REUSEADDR,
(char *) &flag, sizeof(flag)) < 0) {
fprintf(stderr, "Can't set SO_REUSEADDR.\n");
exit(1001);
}
}
} else {
listenSock = socket(AF_UNIX, SOCK_STREAM, 0);
}
if(listenSock < 0) {
return -1;
}
/*
* Bind the listening socket.
*/
if(tcp) {
memset((char *) &sa.inetVariant, 0, sizeof(sa.inetVariant));
sa.inetVariant.sin_family = AF_INET;
sa.inetVariant.sin_addr.s_addr = tcp_ia;
sa.inetVariant.sin_port = htons(port);
servLen = sizeof(sa.inetVariant);
} else {
unlink(bindPath);
if(OS_BuildSockAddrUn(bindPath, &sa.unixVariant, &servLen)) {
fprintf(stderr, "Listening socket's path name is too long.\n");
exit(1000);
}
}
if(bind(listenSock, (struct sockaddr *) &sa.unixVariant, servLen) < 0
|| listen(listenSock, backlog) < 0) {
perror("bind/listen");
exit(errno);
}
return listenSock;
}
/*
*----------------------------------------------------------------------
*
* OS_FcgiConnect --
*
* Create the socket and connect to the remote application if
* possible.
*
* This was lifted from the cgi-fcgi application and was abstracted
* out because Windows NT does not have a domain socket and must
* use a named pipe which has a different API altogether.
*
* Results:
* -1 if fail or a valid file descriptor if connection succeeds.
*
* Side effects:
* Remote connection established.
*
*----------------------------------------------------------------------
*/
int OS_FcgiConnect(char *bindPath)
{
union SockAddrUnion sa;
int servLen, resultSock;
int connectStatus;
char *tp;
char host[MAXPATHLEN];
short port = 0;
int tcp = FALSE;
strcpy(host, bindPath);
if((tp = strchr(host, ':')) != 0) {
*tp++ = 0;
if((port = atoi(tp)) == 0) {
*--tp = ':';
} else {
tcp = TRUE;
}
}
if(tcp == TRUE) {
struct hostent *hp;
if((hp = gethostbyname((*host ? host : "localhost"))) == NULL) {
fprintf(stderr, "Unknown host: %s\n", bindPath);
exit(1000);
}
sa.inetVariant.sin_family = AF_INET;
memcpy(&sa.inetVariant.sin_addr, hp->h_addr, hp->h_length);
sa.inetVariant.sin_port = htons(port);
servLen = sizeof(sa.inetVariant);
resultSock = socket(AF_INET, SOCK_STREAM, 0);
} else {
if(OS_BuildSockAddrUn(bindPath, &sa.unixVariant, &servLen)) {
fprintf(stderr, "Listening socket's path name is too long.\n");
exit(1000);
}
resultSock = socket(AF_UNIX, SOCK_STREAM, 0);
}
ASSERT(resultSock >= 0);
connectStatus = connect(resultSock, (struct sockaddr *) &sa.unixVariant,
servLen);
if(connectStatus >= 0) {
return resultSock;
} else {
/*
* Most likely (errno == ENOENT || errno == ECONNREFUSED)
* and no FCGI application server is running.
*/
close(resultSock);
return -1;
}
}
/*
*--------------------------------------------------------------
*
* OS_Read --
*
* Pass through to the unix read function.
*
* Results:
* Returns number of byes read, 0, or -1 failure: errno
* contains actual error.
*
* Side effects:
* None.
*
*--------------------------------------------------------------
*/
int OS_Read(int fd, char * buf, size_t len)
{
if (shutdownNow) return -1;
return(read(fd, buf, len));
}
/*
*--------------------------------------------------------------
*
* OS_Write --
*
* Pass through to unix write function.
*
* Results:
* Returns number of byes read, 0, or -1 failure: errno
* contains actual error.
*
* Side effects:
* none.
*
*--------------------------------------------------------------
*/
int OS_Write(int fd, char * buf, size_t len)
{
if (shutdownNow) return -1;
return(write(fd, buf, len));
}
/*
*----------------------------------------------------------------------
*
* OS_SpawnChild --
*
* Spawns a new FastCGI listener process.
*
* Results:
* 0 if success, -1 if error.
*
* Side effects:
* Child process spawned.
*
*----------------------------------------------------------------------
*/
int OS_SpawnChild(char *appPath, int listenFd)
{
int forkResult;
forkResult = fork();
if(forkResult < 0) {
exit(errno);
}
if(forkResult == 0) {
/*
* Close STDIN unconditionally. It's used by the parent
* process for CGI communication. The FastCGI applciation
* will be replacing this with the FastCGI listenFd IF
* STDIN_FILENO is the same as FCGI_LISTENSOCK_FILENO
* (which it is on Unix). Regardless, STDIN, STDOUT, and
* STDERR will be closed as the FastCGI process uses a
* multiplexed socket in their place.
*/
close(STDIN_FILENO);
/*
* If the listenFd is already the value of FCGI_LISTENSOCK_FILENO
* we're set. If not, change it so the child knows where to
* get the listen socket from.
*/
if(listenFd != FCGI_LISTENSOCK_FILENO) {
dup2(listenFd, FCGI_LISTENSOCK_FILENO);
close(listenFd);
}
close(STDOUT_FILENO);
close(STDERR_FILENO);
/*
* We're a child. Exec the application.
*
* XXX: entire environment passes through
*/
execl(appPath, appPath, NULL);
/*
* XXX: Can't do this as we've already closed STDERR!!!
*
* perror("exec");
*/
exit(errno);
}
return 0;
}
/*
*--------------------------------------------------------------
*
* OS_AsyncReadStdin --
*
* This initiates an asynchronous read on the standard
* input handle.
*
* The abstraction is necessary because Windows NT does not
* have a clean way of "select"ing a file descriptor for
* I/O.
*
* Results:
* -1 if error, 0 otherwise.
*
* Side effects:
* Asynchronous bit is set in the readfd variable and
* request is enqueued.
*
*--------------------------------------------------------------
*/
int OS_AsyncReadStdin(void *buf, int len, OS_AsyncProc procPtr,
ClientData clientData)
{
int index = AIO_RD_IX(STDIN_FILENO);
asyncIoInUse = TRUE;
ASSERT(asyncIoTable[index].inUse == 0);
asyncIoTable[index].procPtr = procPtr;
asyncIoTable[index].clientData = clientData;
asyncIoTable[index].fd = STDIN_FILENO;
asyncIoTable[index].len = len;
asyncIoTable[index].offset = 0;
asyncIoTable[index].buf = buf;
asyncIoTable[index].inUse = 1;
FD_SET(STDIN_FILENO, &readFdSet);
if(STDIN_FILENO > maxFd)
maxFd = STDIN_FILENO;
return 0;
}
static void GrowAsyncTable(void)
{
int oldTableSize = asyncIoTableSize;
asyncIoTableSize = asyncIoTableSize * 2;
asyncIoTable = (AioInfo *)realloc(asyncIoTable, asyncIoTableSize * sizeof(AioInfo));
if(asyncIoTable == NULL) {
errno = ENOMEM;
exit(errno);
}
memset((char *) &asyncIoTable[oldTableSize], 0,
oldTableSize * sizeof(AioInfo));
}
/*
*--------------------------------------------------------------
*
* OS_AsyncRead --
*
* This initiates an asynchronous read on the file
* handle which may be a socket or named pipe.
*
* We also must save the ProcPtr and ClientData, so later
* when the io completes, we know who to call.
*
* We don't look at any results here (the ReadFile may
* return data if it is cached) but do all completion
* processing in OS_Select when we get the io completion
* port done notifications. Then we call the callback.
*
* Results:
* -1 if error, 0 otherwise.
*
* Side effects:
* Asynchronous I/O operation is queued for completion.
*
*--------------------------------------------------------------
*/
int OS_AsyncRead(int fd, int offset, void *buf, int len,
OS_AsyncProc procPtr, ClientData clientData)
{
int index = AIO_RD_IX(fd);
ASSERT(asyncIoTable != NULL);
asyncIoInUse = TRUE;
if(fd > maxFd)
maxFd = fd;
while (index >= asyncIoTableSize) {
GrowAsyncTable();
}
ASSERT(asyncIoTable[index].inUse == 0);
asyncIoTable[index].procPtr = procPtr;
asyncIoTable[index].clientData = clientData;
asyncIoTable[index].fd = fd;
asyncIoTable[index].len = len;
asyncIoTable[index].offset = offset;
asyncIoTable[index].buf = buf;
asyncIoTable[index].inUse = 1;
FD_SET(fd, &readFdSet);
return 0;
}
/*
*--------------------------------------------------------------
*
* OS_AsyncWrite --
*
* This initiates an asynchronous write on the "fake" file
* descriptor (which may be a file, socket, or named pipe).
* We also must save the ProcPtr and ClientData, so later
* when the io completes, we know who to call.
*
* We don't look at any results here (the WriteFile generally
* completes immediately) but do all completion processing
* in OS_DoIo when we get the io completion port done
* notifications. Then we call the callback.
*
* Results:
* -1 if error, 0 otherwise.
*
* Side effects:
* Asynchronous I/O operation is queued for completion.
*
*--------------------------------------------------------------
*/
int OS_AsyncWrite(int fd, int offset, void *buf, int len,
OS_AsyncProc procPtr, ClientData clientData)
{
int index = AIO_WR_IX(fd);
asyncIoInUse = TRUE;
if(fd > maxFd)
maxFd = fd;
while (index >= asyncIoTableSize) {
GrowAsyncTable();
}
ASSERT(asyncIoTable[index].inUse == 0);
asyncIoTable[index].procPtr = procPtr;
asyncIoTable[index].clientData = clientData;
asyncIoTable[index].fd = fd;
asyncIoTable[index].len = len;
asyncIoTable[index].offset = offset;
asyncIoTable[index].buf = buf;
asyncIoTable[index].inUse = 1;
FD_SET(fd, &writeFdSet);
return 0;
}
/*
*--------------------------------------------------------------
*
* OS_Close --
*
* Closes the descriptor. This is a pass through to the
* Unix close.
*
* Results:
* 0 for success, -1 on failure
*
* Side effects:
* None.
*
*--------------------------------------------------------------
*/
int OS_Close(int fd)
{
if (fd == -1)
return 0;
if (asyncIoInUse) {
int index = AIO_RD_IX(fd);
FD_CLR(fd, &readFdSet);
FD_CLR(fd, &readFdSetPost);
if (asyncIoTable[index].inUse != 0) {
asyncIoTable[index].inUse = 0;
}
FD_CLR(fd, &writeFdSet);
FD_CLR(fd, &writeFdSetPost);
index = AIO_WR_IX(fd);
if (asyncIoTable[index].inUse != 0) {
asyncIoTable[index].inUse = 0;
}
if (maxFd == fd) {
maxFd--;
}
}
/*
* shutdown() the send side and then read() from client until EOF
* or a timeout expires. This is done to minimize the potential
* that a TCP RST will be sent by our TCP stack in response to
* receipt of additional data from the client. The RST would
* cause the client to discard potentially useful response data.
*/
if (shutdown(fd, 1) == 0)
{
struct timeval tv;
fd_set rfds;
int rv;
char trash[1024];
FD_ZERO(&rfds);
do
{
FD_SET(fd, &rfds);
tv.tv_sec = 2;
tv.tv_usec = 0;
rv = select(fd + 1, &rfds, NULL, NULL, &tv);
}
while (rv > 0 && read(fd, trash, sizeof(trash)) > 0);
}
return close(fd);
}
/*
*--------------------------------------------------------------
*
* OS_CloseRead --
*
* Cancel outstanding asynchronous reads and prevent subsequent
* reads from completing.
*
* Results:
* Socket or file is shutdown. Return values mimic Unix shutdown:
* 0 success, -1 failure
*
*--------------------------------------------------------------
*/
int OS_CloseRead(int fd)
{
if(asyncIoTable[AIO_RD_IX(fd)].inUse != 0) {
asyncIoTable[AIO_RD_IX(fd)].inUse = 0;
FD_CLR(fd, &readFdSet);
}
return shutdown(fd, 0);
}
/*
*--------------------------------------------------------------
*
* OS_DoIo --
*
* This function was formerly OS_Select. It's purpose is
* to pull I/O completion events off the queue and dispatch
* them to the appropriate place.
*
* Results:
* Returns 0.
*
* Side effects:
* Handlers are called.
*
*--------------------------------------------------------------
*/
int OS_DoIo(struct timeval *tmo)
{
int fd, len, selectStatus;
OS_AsyncProc procPtr;
ClientData clientData;
AioInfo *aioPtr;
fd_set readFdSetCpy;
fd_set writeFdSetCpy;
asyncIoInUse = TRUE;
FD_ZERO(&readFdSetCpy);
FD_ZERO(&writeFdSetCpy);
for(fd = 0; fd <= maxFd; fd++) {
if(FD_ISSET(fd, &readFdSet)) {
FD_SET(fd, &readFdSetCpy);
}
if(FD_ISSET(fd, &writeFdSet)) {
FD_SET(fd, &writeFdSetCpy);
}
}
/*
* If there were no completed events from a prior call, see if there's
* any work to do.
*/
if(numRdPosted == 0 && numWrPosted == 0) {
selectStatus = select((maxFd+1), &readFdSetCpy, &writeFdSetCpy,
NULL, tmo);
if(selectStatus < 0) {
exit(errno);
}
for(fd = 0; fd <= maxFd; fd++) {
/*
* Build up a list of completed events. We'll work off of
* this list as opposed to looping through the read and write
* fd sets since they can be affected by a callbacl routine.
*/
if(FD_ISSET(fd, &readFdSetCpy)) {
numRdPosted++;
FD_SET(fd, &readFdSetPost);
FD_CLR(fd, &readFdSet);
}
if(FD_ISSET(fd, &writeFdSetCpy)) {
numWrPosted++;
FD_SET(fd, &writeFdSetPost);
FD_CLR(fd, &writeFdSet);
}
}
}
if(numRdPosted == 0 && numWrPosted == 0)
return 0;
for(fd = 0; fd <= maxFd; fd++) {
/*
* Do reads and dispatch callback.
*/
if(FD_ISSET(fd, &readFdSetPost)
&& asyncIoTable[AIO_RD_IX(fd)].inUse) {
numRdPosted--;
FD_CLR(fd, &readFdSetPost);
aioPtr = &asyncIoTable[AIO_RD_IX(fd)];
len = read(aioPtr->fd, aioPtr->buf, aioPtr->len);
procPtr = aioPtr->procPtr;
aioPtr->procPtr = NULL;
clientData = aioPtr->clientData;
aioPtr->inUse = 0;
(*procPtr)(clientData, len);
}
/*
* Do writes and dispatch callback.
*/
if(FD_ISSET(fd, &writeFdSetPost) &&
asyncIoTable[AIO_WR_IX(fd)].inUse) {
numWrPosted--;
FD_CLR(fd, &writeFdSetPost);
aioPtr = &asyncIoTable[AIO_WR_IX(fd)];
len = write(aioPtr->fd, aioPtr->buf, aioPtr->len);
procPtr = aioPtr->procPtr;
aioPtr->procPtr = NULL;
clientData = aioPtr->clientData;
aioPtr->inUse = 0;
(*procPtr)(clientData, len);
}
}
return 0;
}
/*
* Not all systems have strdup().
* @@@ autoconf should determine whether or not this is needed, but for now..
*/
static char * str_dup(const char * str)
{
char * sdup = (char *) malloc(strlen(str) + 1);
if (sdup)
strcpy(sdup, str);
return sdup;
}
/*
*----------------------------------------------------------------------
*
* ClientAddrOK --
*
* Checks if a client address is in a list of allowed addresses
*
* Results:
* TRUE if address list is empty or client address is present
* in the list, FALSE otherwise.
*
*----------------------------------------------------------------------
*/
static int ClientAddrOK(struct sockaddr_in *saPtr, const char *clientList)
{
int result = FALSE;
char *clientListCopy, *cur, *next;
if (clientList == NULL || *clientList == '\0') {
return TRUE;
}
clientListCopy = str_dup(clientList);
for (cur = clientListCopy; cur != NULL; cur = next) {
next = strchr(cur, ',');
if (next != NULL) {
*next++ = '\0';
}
if (inet_addr(cur) == saPtr->sin_addr.s_addr) {
result = TRUE;
break;
}
}
free(clientListCopy);
return result;
}
/*
*----------------------------------------------------------------------
*
* AcquireLock --
*
* On platforms that implement concurrent calls to accept
* on a shared listening ipcFd, returns 0. On other platforms,
* acquires an exclusive lock across all processes sharing a
* listening ipcFd, blocking until the lock has been acquired.
*
* Results:
* 0 for successful call, -1 in case of system error (fatal).
*
* Side effects:
* This process now has the exclusive lock.
*
*----------------------------------------------------------------------
*/
static int AcquireLock(int sock, int fail_on_intr)
{
#ifdef USE_LOCKING
do {
struct flock lock;
lock.l_type = F_WRLCK;
lock.l_start = 0;
lock.l_whence = SEEK_SET;
lock.l_len = 0;
if (fcntl(sock, F_SETLKW, &lock) != -1)
return 0;
} while (errno == EINTR
&& ! fail_on_intr
&& ! shutdownPending);
return -1;
#else
return 0;
#endif
}
/*
*----------------------------------------------------------------------
*
* ReleaseLock --
*
* On platforms that implement concurrent calls to accept
* on a shared listening ipcFd, does nothing. On other platforms,
* releases an exclusive lock acquired by AcquireLock.
*
* Results:
* 0 for successful call, -1 in case of system error (fatal).
*
* Side effects:
* This process no longer holds the lock.
*
*----------------------------------------------------------------------
*/
static int ReleaseLock(int sock)
{
#ifdef USE_LOCKING
do {
struct flock lock;
lock.l_type = F_UNLCK;
lock.l_start = 0;
lock.l_whence = SEEK_SET;
lock.l_len = 0;
if (fcntl(sock, F_SETLK, &lock) != -1)
return 0;
} while (errno == EINTR);
return -1;
#else
return 0;
#endif
}
/**********************************************************************
* Determine if the errno resulting from a failed accept() warrants a
* retry or exit(). Based on Apache's http_main.c accept() handling
* and Stevens' Unix Network Programming Vol 1, 2nd Ed, para. 15.6.
*/
static int is_reasonable_accept_errno (const int error)
{
switch (error) {
#ifdef EPROTO
/* EPROTO on certain older kernels really means ECONNABORTED, so
* we need to ignore it for them. See discussion in new-httpd
* archives nh.9701 search for EPROTO. Also see nh.9603, search
* for EPROTO: There is potentially a bug in Solaris 2.x x<6, and
* other boxes that implement tcp sockets in userland (i.e. on top of
* STREAMS). On these systems, EPROTO can actually result in a fatal
* loop. See PR#981 for example. It's hard to handle both uses of
* EPROTO. */
case EPROTO:
#endif
#ifdef ECONNABORTED
case ECONNABORTED:
#endif
/* Linux generates the rest of these, other tcp stacks (i.e.
* bsd) tend to hide them behind getsockopt() interfaces. They
* occur when the net goes sour or the client disconnects after the
* three-way handshake has been done in the kernel but before
* userland has picked up the socket. */
#ifdef ECONNRESET
case ECONNRESET:
#endif
#ifdef ETIMEDOUT
case ETIMEDOUT:
#endif
#ifdef EHOSTUNREACH
case EHOSTUNREACH:
#endif
#ifdef ENETUNREACH
case ENETUNREACH:
#endif
return 1;
default:
return 0;
}
}
/**********************************************************************
* This works around a problem on Linux 2.0.x and SCO Unixware (maybe
* others?). When a connect() is made to a Unix Domain socket, but its
* not accept()ed before the web server gets impatient and close()s, an
* accept() results in a valid file descriptor, but no data to read.
* This causes a block on the first read() - which never returns!
*
* Another approach to this is to write() to the socket to provoke a
* SIGPIPE, but this is a pain because of the FastCGI protocol, the fact
* that whatever is written has to be universally ignored by all FastCGI
* web servers, and a SIGPIPE handler has to be installed which returns
* (or SIGPIPE is ignored).
*
* READABLE_UNIX_FD_DROP_DEAD_TIMEVAL = 2,0 by default.
*
* Making it shorter is probably safe, but I'll leave that to you. Making
* it 0,0 doesn't work reliably. The shorter you can reliably make it,
* the faster your application will be able to recover (waiting 2 seconds
* may _cause_ the problem when there is a very high demand). At any rate,
* this is better than perma-blocking.
*/
static int is_af_unix_keeper(const int fd)
{
struct timeval tval = { READABLE_UNIX_FD_DROP_DEAD_TIMEVAL };
fd_set read_fds;
FD_ZERO(&read_fds);
FD_SET(fd, &read_fds);
return select(fd + 1, &read_fds, NULL, NULL, &tval) >= 0 && FD_ISSET(fd, &read_fds);
}
/*
*----------------------------------------------------------------------
*
* OS_Accept --
*
* Accepts a new FastCGI connection. This routine knows whether
* we're dealing with TCP based sockets or NT Named Pipes for IPC.
*
* Results:
* -1 if the operation fails, otherwise this is a valid IPC fd.
*
* Side effects:
* New IPC connection is accepted.
*
*----------------------------------------------------------------------
*/
int OS_Accept(int listen_sock, int fail_on_intr, const char *webServerAddrs)
{
int socket = -1;
union {
struct sockaddr_un un;
struct sockaddr_in in;
} sa;
for (;;) {
if (AcquireLock(listen_sock, fail_on_intr))
return -1;
for (;;) {
do {
#ifdef HAVE_SOCKLEN
socklen_t len = sizeof(sa);
#else
int len = sizeof(sa);
#endif
if (shutdownPending) break;
/* There's a window here */
socket = accept(listen_sock, (struct sockaddr *)&sa, &len);
} while (socket < 0
&& errno == EINTR
&& ! fail_on_intr
&& ! shutdownPending);
if (socket < 0) {
if (shutdownPending || ! is_reasonable_accept_errno(errno)) {
int errnoSave = errno;
ReleaseLock(listen_sock);
if (! shutdownPending) {
errno = errnoSave;
}
return (-1);
}
errno = 0;
}
else { /* socket >= 0 */
int set = 1;
if (sa.in.sin_family != AF_INET)
break;
#ifdef TCP_NODELAY
/* No replies to outgoing data, so disable Nagle */
setsockopt(socket, IPPROTO_TCP, TCP_NODELAY, (char *)&set, sizeof(set));
#endif
/* Check that the client IP address is approved */
if (ClientAddrOK(&sa.in, webServerAddrs))
break;
close(socket);
} /* socket >= 0 */
} /* for(;;) */
if (ReleaseLock(listen_sock))
return (-1);
if (sa.in.sin_family != AF_UNIX || is_af_unix_keeper(socket))
break;
close(socket);
} /* while(1) - lock */
return (socket);
}
/*
*----------------------------------------------------------------------
*
* OS_IpcClose
*
* OS IPC routine to close an IPC connection.
*
* Results:
*
*
* Side effects:
* IPC connection is closed.
*
*----------------------------------------------------------------------
*/
int OS_IpcClose(int ipcFd)
{
return OS_Close(ipcFd);
}
/*
*----------------------------------------------------------------------
*
* OS_IsFcgi --
*
* Determines whether this process is a FastCGI process or not.
*
* Results:
* Returns 1 if FastCGI, 0 if not.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
int OS_IsFcgi(int sock)
{
union {
struct sockaddr_in in;
struct sockaddr_un un;
} sa;
#ifdef HAVE_SOCKLEN
socklen_t len = sizeof(sa);
#else
int len = sizeof(sa);
#endif
errno = 0;
if (getpeername(sock, (struct sockaddr *)&sa, &len) != 0 && errno == ENOTCONN) {
return TRUE;
}
else {
return FALSE;
}
}
/*
*----------------------------------------------------------------------
*
* OS_SetFlags --
*
* Sets selected flag bits in an open file descriptor.
*
*----------------------------------------------------------------------
*/
void OS_SetFlags(int fd, int flags)
{
int val;
if((val = fcntl(fd, F_GETFL, 0)) < 0) {
exit(errno);
}
val |= flags;
if(fcntl(fd, F_SETFL, val) < 0) {
exit(errno);
}
}