Documentation Source Text

#include <sys/socket.h>
#include <sys/wait.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdarg.h>
#include <time.h>
#include <sys/times.h>
#include <netdb.h>
#ifdef linux
#include <sys/sendfile.h>
#endif
#include <assert.h>

/*
** Configure the server by setting the following macros and recompiling.

  */
  omitLog = 1;
  if( useTimeout ) alarm(30);
}

#define MAX_PARALLEL 50  /* Number of simultaneous children */

typedef union {
  struct sockaddr sa;
  struct sockaddr_in sa4;
  struct sockaddr_in6 sa6;
  struct sockaddr_storage sas;
} address;

/*
** Implement an HTTP server daemon listening on port iPort.
**
** As new connections arrive, fork a child and let child return
** out of this procedure call.  The child will handle the request.
** The parent never returns from this procedure.
**
** Return 0 to each child as it runs.  If unable to establish a
** listening socket, return non-zero.
*/
int http_server(const char *zPort, int localOnly){
  int listener[20];            /* The server sockets */
  int connection;              /* A socket for each individual connection */
  fd_set readfds;              /* Set of file descriptors for select() */
  address inaddr;              /* Remote address */
  socklen_t lenaddr;           /* Length of the inaddr structure */
  int child;                   /* PID of the child process */
  int nchildren = 0;           /* Number of child processes */
  struct timeval delay;        /* How long to wait inside select() */

  int opt = 1;                 /* setsockopt flag */
  struct addrinfo sHints;      /* Address hints */
  struct addrinfo *pAddrs, *p; /* */
  int rc;                      /* Result code */
  int i, n;
  int maxFd = -1;
  
  memset(&sHints, 0, sizeof(sHints));
  sHints.ai_family = AF_UNSPEC;
  sHints.ai_socktype = SOCK_STREAM;
  sHints.ai_flags = AI_PASSIVE;
  sHints.ai_protocol = 0;
  rc = getaddrinfo(localOnly ? "localhost": 0, zPort, &sHints, &pAddrs);
  if( rc ){
    fprintf(stderr, "could not get addr info: %s", 
            rc!=EAI_SYSTEM ? gai_strerror(rc) : strerror(errno));
    return 1;

  }

  for(n=0, p=pAddrs; n<sizeof(listener)/sizeof(listener[0]) && p!=0;
        p=p->ai_next){
    listener[n] = socket(p->ai_family, p->ai_socktype, p->ai_protocol);
    if( listener[n]>=0 ){
      /* if we can't terminate nicely, at least allow the socket to be reused */
      setsockopt(listener[n], SOL_SOCKET, SO_REUSEADDR,&opt, sizeof(opt));
      
      if( bind(listener[n], p->ai_addr, p->ai_addrlen)<0 ){
        printf("bind failed: %s\n", strerror(errno));
        close(listener[n]);
        continue;
      }
      if( listen(listener[n], 20)<0 ){
        printf("listen() failed: %s\n", strerror(errno));
        close(listener[n]);
        continue;
      }
      n++;
    }


  }
  if( n==0 ){

    fprintf(stderr, "cannot open any sockets\n");
    return 1;
  }



  while( 1 ){
    if( nchildren>MAX_PARALLEL ){
      /* Slow down if connections are arriving too fast */
      sleep( nchildren-MAX_PARALLEL );
    }
    delay.tv_sec = 60;
    delay.tv_usec = 0;
    FD_ZERO(&readfds);
    for(i=0; i<n; i++){
      assert( listener[i]>=0 );
      FD_SET( listener[i], &readfds);
      if( listener[i]>maxFd ) maxFd = listener[i];
    }
    select( maxFd+1, &readfds, 0, 0, &delay);
    for(i=0; i<n; i++){
      if( FD_ISSET(listener[i], &readfds) ){
        lenaddr = sizeof(inaddr);
        connection = accept(listener[i], &inaddr.sa, &lenaddr);
        if( connection>=0 ){
          child = fork();
          if( child!=0 ){
            if( child>0 ) nchildren++;
            close(connection);
          }else{
            int nErr = 0, fd;
            close(0);
            fd = dup(connection);
            if( fd!=0 ) nErr++;
            close(1);
            fd = dup(connection);
            if( fd!=1 ) nErr++;
            close(2);
            fd = dup(connection);
            if( fd!=2 ) nErr++;
            close(connection);
            return nErr;
          }
        }
      }
      /* Bury dead children */
      while( waitpid(0, 0, WNOHANG)>0 ){
        nchildren--;
      }
    }
  }
  /* NOT REACHED */  
  exit(1);
}


int main(int argc, char **argv){
  int i;                    /* Loop counter */
  char *zPermUser = 0;      /* Run daemon with this user's permissions */
  const char *zPort = 0;    /* Implement an HTTP server process */
  int useChrootJail = 1;    /* True to use a change-root jail */
  struct passwd *pwd = 0;   /* Information about the user */

  /* Record the time when processing begins.
  */
  time(&beginTime);

      zRoot = zArg;
    }else if( strcmp(z,"-logfile")==0 ){
      zLogFile = zArg;
    }else if( strcmp(z,"-https")==0 ){
      useHttps = atoi(zArg);
      zHttp = useHttps ? "http" : "https";
    }else if( strcmp(z, "-port")==0 ){
      zPort = zArg;
    }else if( strcmp(z, "-jail")==0 ){
      if( atoi(zArg)==0 ){
        useChrootJail = 0;
      }
    }else if( strcmp(z, "-debug")==0 ){
      if( atoi(zArg) ){
        useTimeout = 0;

      Malfunction(__LINE__, "unable to create chroot jail");
    }else{
      zRoot = "";
    }
  }

  /* Activate the server, if requested */
  if( zPort && http_server(zPort, 0) ){
    Malfunction(__LINE__, "failed to start server");
  }

  /* Drop root privileges.
  */
  if( zPermUser ){
    if( pwd ){