socat/xioread.c

/* source: xioread.c */
/* Copyright Gerhard Rieger 2001-2008 */
/* Published under the GNU General Public License V.2, see file COPYING */

/* this is the source of the extended read function */

#include "xiosysincludes.h"
#include "xioopen.h"

#include "xio-termios.h"
#include "xio-socket.h"
#include "xio-readline.h"
#include "xio-openssl.h"

 
/* xioread() performs read() or recvfrom()
   If result is < 0, errno is valid */
ssize_t xioread(xiofile_t *file, void *buff, size_t bufsiz) {
   ssize_t bytes;
#if WITH_IP6 && 0
   int nexthead;
#endif
   struct single *pipe;
   int _errno;

   if (file->tag == XIO_TAG_INVALID) {
      Error1("xioread(): invalid xiofile descriptor %p", file);
      errno = EINVAL;
      return -1;
   }

   if (file->tag == XIO_TAG_DUAL) {
      pipe = file->dual.stream[0];
      if (pipe->tag == XIO_TAG_INVALID) {
	 Error1("xioread(): invalid xiofile sub descriptor %p[0]", file);
	 errno = EINVAL;
	 return -1;
      }
   } else {
      pipe = &file->stream;
   }

   if (pipe->readbytes) {
      if (pipe->actbytes == 0) {
	 return 0;	/* EOF by count */
      }

      if (pipe->actbytes < bufsiz) {
	 bufsiz = pipe->actbytes;
      }
   }

   switch (pipe->dtype & XIODATA_READMASK) {
   case XIOREAD_STREAM:
      do {
	 bytes = Read(pipe->fd, buff, bufsiz);
      } while (bytes < 0 && errno == EINTR);
      if (bytes < 0) {
	 _errno = errno;
	 switch (_errno) {
#if 1
	 case EPIPE: case ECONNRESET:
	    Warn4("read(%d, %p, "F_Zu"): %s",
		  pipe->fd, buff, bufsiz, strerror(_errno));
	    break;
#endif
	 default:
	    Error4("read(%d, %p, "F_Zu"): %s",
		   pipe->fd, buff, bufsiz, strerror(_errno));
	 }
	 errno = _errno;
	 return -1;
      }
      break;

   case XIOREAD_PTY:
      do {
	 bytes = Read(pipe->fd, buff, bufsiz);
      } while (bytes < 0 && errno == EINTR);
      if (bytes < 0) {
	 _errno = errno;
	 if (_errno == EIO) {
	    Notice4("read(%d, %p, "F_Zu"): %s (probably PTY closed)",
		    pipe->fd, buff, bufsiz, strerror(_errno));
	    return 0;
	 } else {
	    Error4("read(%d, %p, "F_Zu"): %s",
		   pipe->fd, buff, bufsiz, strerror(_errno));
	 }
	 errno = _errno;
	 return -1;
      }
      break;

#if WITH_READLINE
   case XIOREAD_READLINE:
      if ((bytes = xioread_readline(pipe, buff, bufsiz)) < 0) {
	 return -1;
      }      
      break;
#endif /* WITH_READLINE */

#if WITH_OPENSSL
   case XIOREAD_OPENSSL:
      /* this function prints its error messages */
      if ((bytes = xioread_openssl(pipe, buff, bufsiz)) < 0) {
	 return -1;
      }
      break;
#endif /* WITH_OPENSSL */

#if WITH_SOCKET
   case XIOREAD_RECV:
     if (pipe->dtype & XIOREAD_RECV_FROM) {
#if WITH_RAWIP || WITH_UDP || WITH_UNIX
      union sockaddr_union from = {{0}};
      socklen_t fromlen = sizeof(from);
      char infobuff[256];

      do {
	 bytes =
	    Recvfrom(pipe->fd, buff, bufsiz, 0, &from.soa, &fromlen);
      } while (bytes < 0 && errno == EINTR);
      if (bytes < 0) {
	 char infobuff[256];
	 _errno = errno;
	 Error6("recvfrom(%d, %p, "F_Zu", 0, %s, {"F_socklen"}): %s",
		pipe->fd, buff, bufsiz,
		sockaddr_info(&from.soa, fromlen, infobuff, sizeof(infobuff)),
		fromlen, strerror(errno));
	 errno = _errno;
	 return -1;
      }
      Notice2("received packet with "F_Zu" bytes from %s",
	      bytes,
	      sockaddr_info(&from.soa, fromlen, infobuff, sizeof(infobuff)));
      if (bytes == 0) {
	 if (!pipe->para.socket.emptyiseof) {
	    errno = EAGAIN; return -1;
	 }
	 return bytes;
      }

      if (pipe->peersa.soa.sa_family != PF_UNSPEC) {
	 /* a peer address is registered, so we need to check if it matches */
#if 0 /* with UNIX sockets we find inconsistent lengths */
	 if (fromlen != pipe->salen) {
	    Info("recvfrom(): wrong peer address length, ignoring packet");
	    errno = EAGAIN; return -1;
	 }
#endif
	 if (pipe->dtype & XIOREAD_RECV_SKIPIP) {
	    if (pipe->peersa.soa.sa_family != from.soa.sa_family) {
	       Info("recvfrom(): wrong peer protocol, ignoring packet");
	       errno = EAGAIN; return -1;
	    }
#if WITH_IP4
	    switch (pipe->peersa.soa.sa_family) {
	    case PF_INET:
	       if (pipe->peersa.ip4.sin_addr.s_addr !=
		   from.ip4.sin_addr.s_addr) {
		  Info("recvfrom(): wrong peer address, ignoring packet");
		  errno = EAGAIN; return -1;
	       }
	       break;
	    }
#endif /* WITH_IP4 */
	 } else {
	    switch (pipe->peersa.soa.sa_family) {
#if 0
	    case PF_UNIX:
	       if (strncmp(pipe->peersa.un.sun_path, from.un.sun_path,
			   sizeof(from.un.sun_path))) {
		  Info("recvfrom(): wrong peer address, ignoring packet");
		  errno = EAGAIN; return -1;
	       }
	       break;
#endif
#if WITH_IP6
	    case PF_INET6:
	       /* e.g. Solaris recvfrom sets a __sin6_src_id component */
	       if (memcmp(&from.ip6.sin6_addr, &pipe->peersa.ip6.sin6_addr,
			  sizeof(from.ip6.sin6_addr)) ||
		   from.ip6.sin6_port != pipe->peersa.ip6.sin6_port) {
		  Info("recvfrom(): wrong peer address, ignoring packet");
		  errno = EAGAIN; return -1;
	       }
	       break;
#endif /* WITH_IP6 */
	    default:
	       if (memcmp(&from, &pipe->peersa, fromlen)) {
		  Info("recvfrom(): wrong peer address, ignoring packet");
		  errno = EAGAIN; return -1;
	       }
	    }
	 }
      }

      switch(from.soa.sa_family) {
	 int headlen;
#if WITH_IP4
      case AF_INET:
	 if (pipe->dtype & XIOREAD_RECV_SKIPIP) {
	    /* IP4 raw sockets include the header when passing a packet to the
	       application - we don't need it here. */
#if HAVE_STRUCT_IP_IP_HL
	    headlen = 4*((struct ip *)buff)->ip_hl;
#else /* happened on Tru64 */
	    headlen = 4*((struct ip *)buff)->ip_vhl;
#endif
	    if (headlen > bytes) {
	       Warn1("xioread(%d, ...)/IP4: short packet", pipe->fd);
	       bytes = 0;
	    } else {
	       memmove(buff, ((char *)buff)+headlen, bytes-headlen);
	       bytes -= headlen;
	    }
	 }
	 break;
#endif
#if WITH_IP6
      case AF_INET6:
	 /* does not seem to include header on Linux */
	 /* but sometimes on AIX */
	 break;
#endif
      default:
	 /* do nothing, for now */
	 break;
      }
      if (pipe->dtype & XIOREAD_RECV_ONESHOT) {
#if 1
	 pipe->eof = 2;
#else
	 Shutdown(pipe->fd, SHUT_RD);
#endif
	 if (pipe->ppid > 0) {
	    Kill(pipe->ppid, SIGUSR1);
	 }
      }

#if 0
      if (fromlen != pipe->fd[0].salen) {
	 Debug("recvfrom(): wrong peer address length, ignoring packet");
	 continue;
      }
      if (memcmp(&from, &pipe->fd[0].peersa.sa, fromlen)) {
	 Debug("recvfrom(): other peer address, ignoring packet");
	 Debug16("peer: %02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
		 pipe->fd[0].peersa.space[0],
		 pipe->fd[0].peersa.space[1],
		 pipe->fd[0].peersa.space[2],
		 pipe->fd[0].peersa.space[3],
		 pipe->fd[0].peersa.space[4],
		 pipe->fd[0].peersa.space[5],
		 pipe->fd[0].peersa.space[6],
		 pipe->fd[0].peersa.space[7],
		 pipe->fd[0].peersa.space[8],
		 pipe->fd[0].peersa.space[9],
		 pipe->fd[0].peersa.space[10],
		 pipe->fd[0].peersa.space[11],
		 pipe->fd[0].peersa.space[12],
		 pipe->fd[0].peersa.space[13],
		 pipe->fd[0].peersa.space[14],
		 pipe->fd[0].peersa.space[15]);
	 Debug16("from: %02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
		 from.space[0], from.space[1],
		 from.space[2], from.space[3],
		 from.space[4], from.space[5],
		 from.space[6], from.space[7],
		 from.space[8], from.space[9],
		 from.space[10], from.space[11],
		 from.space[12], from.space[13],
		 from.space[14], from.space[15]);
	 continue;
      }
#endif
#else /* !WITH_RAWIP */
      Fatal("address requires raw sockets, but they are not compiled in");
      return -1;
#endif /* !WITH_RAWIP || WITH_UDP || WITH_UNIX */

     } else /* ~XIOREAD_RECV_FROM */ {
      union sockaddr_union from;  socklen_t fromlen = sizeof(from);
      char infobuff[256];

      socket_init(pipe->para.socket.la.soa.sa_family, &from);
      /* get source address */
      if (xiogetpacketsrc(pipe->fd, &from, &fromlen) < 0) {
	 return STAT_RETRYNOW;
      }
      if (xiocheckpeer(pipe, &from, &pipe->para.socket.la) < 0) {
	 Recvfrom(pipe->fd, buff, bufsiz, 0, &from.soa, &fromlen);  /* drop */
	 errno = EAGAIN;  return -1;
      }
      Info1("permitting packet from %s",
	    sockaddr_info((struct sockaddr *)&from, fromlen,
			  infobuff, sizeof(infobuff)));

      do {
	 bytes =
	    Recvfrom(pipe->fd, buff, bufsiz, 0, &from.soa, &fromlen);
      } while (bytes < 0 && errno == EINTR);
      if (bytes < 0) {
	 char infobuff[256];
	 _errno = errno;
	 Error6("recvfrom(%d, %p, "F_Zu", 0, %s, "F_socklen"): %s",
		pipe->fd, buff, bufsiz,
		sockaddr_info(&from.soa, fromlen, infobuff, sizeof(infobuff)),
		fromlen, strerror(errno));
	 errno = _errno;
	 return -1;
      }
      Notice2("received packet with "F_Zu" bytes from %s",
	      bytes,
	      sockaddr_info(&from.soa, fromlen, infobuff, sizeof(infobuff)));
      if (bytes == 0) {
	 if (!pipe->para.socket.emptyiseof) {
	    errno = EAGAIN; return -1;
	 }
	 return bytes;
      }

      switch(from.soa.sa_family) {
	 int headlen;
#if WITH_IP4
      case AF_INET:
	 if (pipe->dtype & XIOREAD_RECV_SKIPIP) {
	    /* IP4 raw sockets include the header when passing a packet to the
	       application - we don't need it here. */
#if HAVE_STRUCT_IP_IP_HL
	    headlen = 4*((struct ip *)buff)->ip_hl;
#else /* happened on Tru64 */
	    headlen = 4*((struct ip *)buff)->ip_vhl;
#endif
	    if (headlen > bytes) {
	       Warn1("xioread(%d, ...)/IP4: short packet", pipe->fd);
	       bytes = 0;
	    } else {
	       memmove(buff, ((char *)buff)+headlen, bytes-headlen);
	       bytes -= headlen;
	    }
	 }
	 break;
#endif
#if WITH_IP6
      case AF_INET6: /* does not seem to include header... */
	 break;
#endif
      default:
	 /* do nothing, for now */
	 break;
      }

     }
     break;
#endif /* WITH_SOCKET */

   default:
      Error("internal: undefined read operation");
      errno = EINVAL;  return -1;
   }
   pipe->actbytes -= bytes;
   return bytes;
}


/* this function is intended only for some special address types where the
   select() call cannot strictly determine if (more) read data is available.
   currently this is for the OpenSSL based addresses.
*/
ssize_t xiopending(xiofile_t *file) {
   struct single *pipe;

   if (file->tag == XIO_TAG_INVALID) {
      Error1("xiopending(): invalid xiofile descriptor %p", file);
      errno = EINVAL;
      return -1;
   }

   if (file->tag == XIO_TAG_DUAL) {
      pipe = file->dual.stream[0];
      if (pipe->tag == XIO_TAG_INVALID) {
	 Error1("xiopending(): invalid xiofile sub descriptor %p[0]", file);
	 errno = EINVAL;
	 return -1;
      }
   } else {
      pipe = &file->stream;
   }

   switch (pipe->dtype & XIODATA_READMASK) {
#if WITH_OPENSSL
   case XIOREAD_OPENSSL:
      return xiopending_openssl(pipe);
#endif /* WITH_OPENSSL */
   default:
      return 0;
   }
}