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/*
** Copyright 2007 Double Precision, Inc.
** See COPYING for distribution information.
*/
/*
*/
#include "cgi.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#if TIME_WITH_SYS_TIME
#include <sys/time.h>
#include <time.h>
#else
#if HAVE_SYS_TIME_H
#include <sys/time.h>
#else
#include <time.h>
#endif
#endif
#if HAVE_SYS_WAIT_H
#include <sys/wait.h>
#endif
#include <errno.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <sys/un.h>
static int read_environ(int);
static int start_daemon(const char *lockfilename);
static void run_daemon(int fd, int termfd, int connfd, void (*handler)(void *),
void *dummy);
static void run_prefork(int fd, size_t ndaemons, void (*handler)(void *),
void *dummy);
void cgi_daemon(int nprocs, const char *lockfile,
void (*postinit)(void *), void (*handler)(void *),
void *dummy)
{
int fd=start_daemon(lockfile);
if (postinit)
(*postinit)(dummy);
if (nprocs > 0)
run_prefork(fd, nprocs, handler, dummy);
else
run_daemon(fd, -1, -1, handler, dummy);
}
/* Start in daemon mode. Return listening socket file descriptor */
static int start_daemon(const char *lockfile)
{
int fd;
struct sockaddr_un skun;
unlink(lockfile);
fd=socket(PF_UNIX, SOCK_STREAM, 0);
if (fd < 0)
{
perror("socket");
return (-1);
}
skun.sun_family=AF_UNIX;
strcpy(skun.sun_path, lockfile);
if (bind(fd, (const struct sockaddr *)&skun, sizeof(skun)) ||
listen(fd, SOMAXCONN) ||
chmod(skun.sun_path, 0777) ||
fcntl(fd, F_SETFL, O_NONBLOCK) < 0)
{
perror(lockfile);
close(fd);
return (-1);
}
return fd;
}
static int prefork(int listenfd, int *allpipes, size_t ndaemos,
int *termpipe, void (*handler)(void *), void *dummy);
static void run_prefork(int fd, size_t ndaemons, void (*handler)(void *),
void *dummy)
{
int *cpipes; /* Completion pipes from preforked processes */
int termpipe[2]; /* Termination pipe to preforked processes */
size_t i;
if ((cpipes=malloc(sizeof(int)*ndaemons)) == NULL)
{
fprintf(stderr,
"CRIT: malloc failed: %s\n",
strerror(errno));
exit(1);
}
if (pipe(termpipe) < 0)
{
fprintf(stderr,
"CRIT: pipe failed: %s\n",
strerror(errno));
exit(1);
}
/* Start the initial set of preforked daemons */
for (i=0; i<ndaemons; i++)
cpipes[i]= -1;
for (i=0; i<ndaemons; i++)
cpipes[i]=prefork(fd, cpipes, ndaemons, termpipe, handler,
dummy);
for (;;)
{
fd_set fdr;
int maxfd=0;
FD_ZERO(&fdr);
for (i=0; i<ndaemons; i++)
{
if (cpipes[i] >= maxfd)
maxfd=cpipes[i]+1;
FD_SET(cpipes[i], &fdr);
}
if (select(maxfd, &fdr, NULL, NULL, NULL) <= 0)
continue;
/*
** When child process gets a connection, it closes its
** completion pipe, which makes the pipe selectable for
** read.
*/
for (i=0; i<ndaemons; i++)
{
if (FD_ISSET(cpipes[i], &fdr))
{
close(cpipes[i]);
cpipes[i]= -1;
cpipes[i]=prefork(fd, cpipes,
ndaemons, termpipe, handler,
dummy);
}
}
}
}
/* Start a preforked process */
static int prefork(int listenfd, int *allpipes, size_t ndaemons,
int *termpipe, void (*handler)(void *), void *dummy)
{
int newpipe[2];
pid_t p;
int waitstat;
size_t i;
if (pipe(newpipe) < 0)
{
fprintf(stderr,
"CRIT: pipe failed: %s\n", strerror(errno));
exit(1);
}
while ((p=fork()) < 0)
{
fprintf(stderr,
"CRIT: fork failed: %s\n", strerror(errno));
sleep(5);
}
if (p) /* parent */
{
close(newpipe[1]);
/* Wait for first child process to go away */
while (wait(&waitstat) != p)
;
return (newpipe[0]);
}
close(newpipe[0]);
close(termpipe[1]);
/* New child doesn't need pipes from other children */
for (i=0; i<ndaemons; i++)
if (allpipes[i] >= 0)
close(allpipes[i]);
/* Fork once more, so that the parent process can continue */
if (fork())
exit(0);
run_daemon(listenfd, termpipe[0], newpipe[1], handler, dummy);
return (-1);
}
static void run_daemon(int fd, int termfd, int acceptedfd,
void (*handler)(void *), void *dummy)
{
int cfd;
for (;;)
{
fd_set fdr;
pid_t p;
int maxfd;
FD_ZERO(&fdr);
FD_SET(fd, &fdr);
maxfd=fd;
if (termfd >= 0)
{
if (termfd > maxfd)
maxfd=termfd;
FD_SET(termfd, &fdr);
}
if (select(maxfd+1, &fdr, NULL, NULL, NULL) <= 0)
continue;
if (termfd >= 0 &&
FD_ISSET(termfd, &fdr)) /* Terminate all child procs */
exit(0);
if (!FD_ISSET(fd, &fdr))
continue;
cfd=accept(fd, NULL, 0);
if (cfd < 0)
continue;
if (acceptedfd >= 0) /* preforked daemon */
{
if (termfd >= 0)
close(termfd);
close(acceptedfd);
break;
}
p=fork();
if (p < 0)
{
fprintf(stderr,
"CRIT: fork() failed: %s\n", strerror(errno));
continue;
}
if (p)
{
int dummy;
close(cfd);
while (wait(&dummy) != p)
continue;
continue;
}
/* Child forks once more, parent exits */
if (fork())
exit(0);
break;
}
/* child */
if (fcntl(cfd, F_SETFL, 0) < 0)
{
fprintf(stderr,
"CRIT: fcntl(): %s\n", strerror(errno));
exit(0);
}
close(fd);
if (read_environ(cfd))
{
close(0);
close(1);
if (dup(cfd) != 0 || dup(cfd) != 1)
{
fprintf(stderr,
"CRIT: dup() did not work as expected\n");
exit(0);
}
close(cfd);
}
if (fcntl(0, F_SETFL, 0) < 0 ||
fcntl(1, F_SETFL, 0) < 0)
{
fprintf(stderr,
"CRIT: fcntl() failed: %s\n", strerror(errno));
exit(0);
}
(*handler)(dummy);
exit(0);
}
/* Read environment from the sqwebmail stub */
static void force_read(int cfd, char *p, size_t l)
{
int m;
while (l)
{
m=read(cfd, p, l);
if (m <= 0)
{
fprintf(stderr,
"WARN: socket closed while reading"
" environment.\n");
exit(0);
}
p += m;
l -= m;
}
}
/* Receive CGI environment */
static int read_environ(int cfd)
{
static char buf[SOCKENVIRONLEN];
size_t l;
char *p;
int passfd;
force_read(cfd, buf, 1+sizeof(l));
memcpy(&l, buf, sizeof(l));
passfd=buf[sizeof(l)];
if (l >= sizeof(buf))
{
fprintf(stderr,
"WARN: invalid environment received via socket.\n");
exit(0);
}
alarm(10); /* Just in case - punt */
force_read(cfd, buf, l);
buf[l]=0;
alarm(0);
/* Vet environment strings for only known good strings */
p=buf;
while (p < buf+l)
{
if (strchr(p, '=') == NULL ||
!VALIDCGIVAR(p))
{
fprintf(stderr,
"WARN: invalid environment received"
" via socket: %s\n" , p);
exit(0);
}
putenv(p);
while (*p++)
;
}
/* Receive file descriptors, if supported by the platform */
#if CGI_PASSFD
if (passfd)
{
struct iovec iov;
char dummy;
#if CGI_PASSFD_MSGACCRIGHTS
int fdbuf[2];
struct msghdr msg;
#endif
#if CGI_PASSFD_MSGCONTROL
int fdbuf[2];
struct msghdr msg;
struct cmsghdr *cmsg;
char buf[CMSG_SPACE(sizeof(fdbuf))];
#endif
#if CGI_PASSFD_MSGACCRIGHTS
memset(&iov, 0, sizeof(iov));
msg.msg_accrights=(caddr_t)fdbuf;
msg.msg_accrightslen=sizeof(fdbuf);
#endif
#if CGI_PASSFD_MSGCONTROL
memset(&msg, 0, sizeof(msg));
msg.msg_control=buf;
msg.msg_controllen=sizeof(buf);
#endif
msg.msg_iov=&iov;
msg.msg_iovlen=1;
iov.iov_base=&dummy;
iov.iov_len=1;
if (recvmsg(cfd, &msg, 0) <= 0)
{
perror("Internal error - recvmsg() failed");
exit(0);
}
#if CGI_PASSFD_MSGACCRIGHTS
if (msg.msg_accrightslen < sizeof(fdbuf))
{
perror("Internal error - malformed recvmsg()");
exit(0);
}
#endif
#if CGI_PASSFD_MSGCONTROL
if (msg.msg_controllen < sizeof(buf) ||
(cmsg = CMSG_FIRSTHDR(&msg))->cmsg_level != SOL_SOCKET ||
cmsg->cmsg_type != SCM_RIGHTS ||
cmsg->cmsg_len != CMSG_LEN(sizeof(fdbuf)))
{
perror("Internal error - malformed recvmsg()");
exit(0);
}
memcpy(fdbuf, CMSG_DATA(cmsg), sizeof(fdbuf));
#endif
close(0);
close(1);
if (dup(fdbuf[0]) != 0 || dup(fdbuf[1]) != 1)
fprintf(stderr,
"CRIT: dup() did not work as expected in"
" read_environ()\n");
close(fdbuf[0]);
close(fdbuf[1]);
return 0;
}
#endif
return 1;
}
