new address option "escape" allows to break a socat instance

CHANGES

@@ -1,4 +1,8 @@
 
+new features:
+	new address option "escape" allows to break a socat instance even when
+	raw terminal mode prevents ^C etc.
+
 corrections:
 	some raw IP and UNIX datagram modes failed on BSD systems
 

VERSION

@@ -1 +1 @@
-"1.6.0.1+ip4bind+recvfromfork+x64+execstderr+execspaces+cosmetics+poll+udplistencont+ignoreeofunblock"
+"1.6.0.1+ip4bind+recvfromfork+x64+execstderr+execspaces+cosmetics+poll+udplistencont+ignoreeofunblock+escape"

doc/socat.yo

@@ -10,7 +10,7 @@ def(Filan)(0)(bf(Filan))
 def(procan)(0)(bf(procan))
 def(Procan)(0)(bf(Procan))
 
-manpage(socat)(1)(Feb 2008)(socat)()
+manpage(socat)(1)(Jul 2008)(socat)()
 
 whenhtml(
 label(CONTENTS)
@@ -1516,6 +1516,10 @@ label(OPTION_LOCKFILE)dit(bf(tt(lockfile=<filename>)))
 label(OPTION_WAITLOCK)dit(bf(tt(waitlock=<filename>)))
    If lockfile exists, waits until it disappears. When lockfile does not exist,
    creates it and continues, unlinks lockfile on exit.
+label(OPTION_ESCAPE)dit(bf(tt(escape=<int>)))
+   Specifies the numeric code of a character that triggers EOF on the input
+   stream. It is useful with a terminal in raw mode
+   (link(example)(EXAMPLE_OPTION_ESCAPE)).
 enddit()
 
 startdit()enddit()nl()
@@ -2630,13 +2634,15 @@ at most 512 data bytes per packet (link(mss)(OPTION_MSS)).
 label(EXAMPLE_ADDRESS_GOPEN)
 label(EXAMPLE_OPTION_RAW)
 label(EXAMPLE_OPTION_ECHO)
-dit(bf(tt(socat - /dev/ttyS0,raw,echo=0,crnl)))
+label(EXAMPLE_OPTION_ESCAPE)
+dit(bf(tt(socat -,raw,echo=0,escape=0x0f /dev/ttyS0,raw,echo=0,crnl)))
 
 Opens an interactive connection via the serial line, e.g. for talking with a
-modem. link(raw)(OPTION_RAW) and link(echo)(OPTION_ECHO) set ttyS0's terminal
+modem. link(raw)(OPTION_RAW) and link(echo)(OPTION_ECHO) set the console's and
-parameters to practicable values, link(crnl)(OPTION_CRNL) 
+ttyS0's terminal parameters to practicable values, link(crnl)(OPTION_CRNL) 
-converts to correct newline characters. Consider using
+converts to correct newline characters. link(escape)(OPTION_ESCAPE) allows to
-link(READLINE)(ADDRESS_READLINE) instead of `-'.
+terminate the socat process with character control-O. 
+Consider using link(READLINE)(ADDRESS_READLINE) instead of the first address.
 
 
 label(EXAMPLE_ADDRESS_UNIX_LISTEN)

socat.c

@@ -948,6 +948,10 @@ int _socat(void) {
 	       /* avoid idle when all readbytes already there */
 	       mayrd1 = true;
 	    }
+	    /* escape char occurred? */
+	    if (XIO_RDSTREAM(sock1)->actescape) {
+	       bytes1 = 0;	/* indicate EOF */
+	    }
 	 }
 	 /* (bytes1 == 0)  handled later */
       } else {
@@ -976,6 +980,10 @@ int _socat(void) {
 	       /* avoid idle when all readbytes already there */
 	       mayrd2 = true;
 	    }          
+	    /* escape char occurred? */
+	    if (XIO_RDSTREAM(sock2)->actescape) {
+	       bytes2 = 0;	/* indicate EOF */
+	    }
 	 }
 	 /* (bytes2 == 0)  handled later */
       } else {
@@ -988,7 +996,8 @@ int _socat(void) {
 	     bytes1, XIO_RDSTREAM(sock1)->eof, XIO_RDSTREAM(sock1)->ignoreeof,
 	     closing);*/
       if (bytes1 == 0 || XIO_RDSTREAM(sock1)->eof >= 2) {
-	 if (XIO_RDSTREAM(sock1)->ignoreeof && !closing) {
+	 if (XIO_RDSTREAM(sock1)->ignoreeof &&
+	     !XIO_RDSTREAM(sock1)->actescape && !closing) {
 	    Debug1("socket 1 (fd %d) is at EOF, ignoring",
 		   XIO_RDSTREAM(sock1)->fd);	/*! */
 	    mayrd1 = true;
@@ -996,16 +1005,20 @@ int _socat(void) {
 	 } else {
 	    Notice1("socket 1 (fd %d) is at EOF", XIO_GETRDFD(sock1));
 	    xioshutdown(sock2, SHUT_WR);
+	    XIO_RDSTREAM(sock1)->eof = 2;
+	    XIO_RDSTREAM(sock1)->ignoreeof = false;
 	    if (socat_opts.lefttoright) {
 	       break;
 	    }
+	    closing = 1;
 	 }
       } else if (polling && XIO_RDSTREAM(sock1)->ignoreeof) {
 	 polling = 0;
       }
 
       if (bytes2 == 0 || XIO_RDSTREAM(sock2)->eof >= 2) {
-	 if (XIO_RDSTREAM(sock2)->ignoreeof && !closing) {
+	 if (XIO_RDSTREAM(sock2)->ignoreeof &&
+	     !XIO_RDSTREAM(sock2)->actescape && !closing) {
 	    Debug1("socket 2 (fd %d) is at EOF, ignoring",
 		   XIO_RDSTREAM(sock2)->fd);
 	    mayrd2 = true;
@@ -1013,9 +1026,12 @@ int _socat(void) {
 	 } else {
 	    Notice1("socket 2 (fd %d) is at EOF", XIO_GETRDFD(sock2));
 	    xioshutdown(sock1, SHUT_WR);
+	    XIO_RDSTREAM(sock2)->eof = 2;
+	    XIO_RDSTREAM(sock2)->ignoreeof = false;
 	    if (socat_opts.righttoleft) {
 	       break;
 	    }
+	    closing = 1;
 	 }
       } else if (polling && XIO_RDSTREAM(sock2)->ignoreeof) {
 	 polling = 0;
@@ -1102,8 +1118,9 @@ static int
 
 /* inpipe is suspected to have read data available; read at most bufsiz bytes
    and transfer them to outpipe. Perform required data conversions.
-   buff should be at least twice as large as bufsiz, to allow all standard
+   buff must be a malloc()'ed storage and might be realloc()'ed in this
-   conversions. Returns the number of bytes written, or 0 on EOF or <0 if an
+   function if more space is required after conversions. 
+   Returns the number of bytes written, or 0 on EOF or <0 if an
    error occurred or when data was read but none written due to conversions
    (with EAGAIN). EAGAIN also occurs when reading from a nonblocking FD where
    the file has a mandatory lock.
@@ -1113,9 +1130,9 @@ static int
 /* inpipe, outpipe must be single descriptors (not dual!) */
 int xiotransfer(xiofile_t *inpipe, xiofile_t *outpipe,
 		unsigned char **buff, size_t bufsiz, bool righttoleft) {
-   ssize_t bytes, writt;
+   ssize_t bytes, writt = 0;
 
-	 bytes = xioread(inpipe, *buff, socat_opts.bufsiz);
+	 bytes = xioread(inpipe, *buff, bufsiz);
 	 if (bytes < 0) {
 	    if (errno != EAGAIN)
 	       XIO_RDSTREAM(inpipe)->eof = 2;
@@ -1123,14 +1140,35 @@ int xiotransfer(xiofile_t *inpipe, xiofile_t *outpipe,
 	    return -1;
 	 }
 	 if (bytes == 0 && XIO_RDSTREAM(inpipe)->ignoreeof && !closing) {
-	    writt = 0;
+	    ;
 	 } else if (bytes == 0) {
 	    XIO_RDSTREAM(inpipe)->eof = 2;
 	    closing = MAX(closing, 1);
-	    writt = 0;
 	 }
 
-	 else /* if (bytes > 0)*/ {
+	 if (bytes > 0) {
+	    /* handle escape char */
+	    if (XIO_RDSTREAM(inpipe)->escape != -1) {
+	       /* check input data for escape char */
+	       unsigned char *ptr = *buff;
+	       size_t ctr = 0;
+	       while (ctr < bytes) {
+		  if (*ptr == XIO_RDSTREAM(inpipe)->escape) {
+		     /* found: set flag, truncate input data */
+		     XIO_RDSTREAM(inpipe)->actescape = true;
+		     bytes = ctr;
+		     Info("escape char found in input");
+		     break;
+		  }
+		  ++ptr; ++ctr;
+	       }
+	       if (ctr != bytes) {
+		  XIO_RDSTREAM(inpipe)->eof = 2;
+	       }
+	    }
+	 }
+
+	    if (bytes > 0) {
 
 	    if (XIO_RDSTREAM(inpipe)->lineterm !=
 		XIO_WRSTREAM(outpipe)->lineterm) {
@@ -1248,8 +1286,14 @@ int xiotransfer(xiofile_t *inpipe, xiofile_t *outpipe,
 #define LF '\n'
 
 
-int cv_newline(unsigned char **buff, ssize_t *bytes,
+/* converts the newline characters (or character sequences) from the one
+   specified in lineterm1 to that of lineterm2. Possible values are
+   LINETERM_CR, LINETERM_CRNL, LINETERM_RAW.
+   buff points to the malloc()'ed data, input and output. It may be subject to
+   realloc(). bytes specifies the number of bytes input and output */
+int cv_newline(unsigned char **buff, ssize_t *bufsiz,
 	       int lineterm1, int lineterm2) {
+   ssize_t *bytes = bufsiz;
    /* must perform newline changes */
    if (lineterm1 <= LINETERM_CR && lineterm2 <= LINETERM_CR) {
       /* no change in data length */
@@ -1287,7 +1331,7 @@ int cv_newline(unsigned char **buff, ssize_t *bytes,
 	    *t++ = *s++;
 	 }
       }
-      *bytes = t - *buff;
+      *bufsiz = t - *buff;
    } else {
       /* buffer becomes longer, must alloc another space */
       unsigned char *buf2;
@@ -1297,7 +1341,7 @@ int cv_newline(unsigned char **buff, ssize_t *bytes,
       } else {
 	 from = '\r';
       }
-      if ((buf2 = Malloc(2*socat_opts.bufsiz+1)) == NULL) {
+      if ((buf2 = Malloc(2*socat_opts.bufsiz/*sic!*/+1)) == NULL) {
 	 return -1;
       }
       s = *buff;  t = buf2;  z = *buff + *bytes;
@@ -1312,7 +1356,7 @@ int cv_newline(unsigned char **buff, ssize_t *bytes,
       }
       free(*buff);
       *buff = buf2;
-      *bytes = t - buf2;;
+      *bufsiz = t - buf2;;
    }
    return 0;
 }

test.sh

@@ -8447,6 +8447,69 @@ esac
 N=$((N+1))
 
 
+# test the escape option
+NAME=ESCAPE
+case "$TESTS" in
+*%functions%*|*%escape%*|*%$NAME%*)
+TEST="$NAME: escape character triggers EOF"
+# idea: start socat just echoing input, but apply escape option. send a string
+# containing the escape character and check if the output is truncated
+tf="$td/test$N.stdout"
+te="$td/test$N.stderr"
+tdiff="$td/test$N.diff"
+da="test$N $(date) $RANDOM"
+CMD="$SOCAT $opts -,escape=27 pipe"
+printf "test $F_n $TEST... " $N
+$ECHO "$da\n\x1bXYZ" |$CMD >"$tf" 2>"$te"
+if [ $? -ne 0 ]; then
+    $PRINTF "$FAILED: $SOCAT:\n"
+    echo "$CMD"
+    cat "$te"
+    numFAIL=$((numFAIL+1))
+elif ! echo "$da" |diff - "$tf" >"$tdiff"; then
+    $PRINTF "$FAILED: diff:\n"
+    cat "$tdiff"
+    numFAIL=$((numFAIL+1))
+else
+    $PRINTF "$OK\n"
+    if [ -n "$debug" ]; then cat $te; fi
+    numOK=$((numOK+1))
+fi
+esac
+N=$((N+1))
+
+# test the escape option combined with ignoreeof
+NAME=ESCAPE_IGNOREEOF
+case "$TESTS" in
+*%functions%*|*%ignoreeof%*|*%escape%*|*%$NAME%*)
+TEST="$NAME: escape character triggers EOF"
+# idea: start socat just echoing input, but apply escape option. send a string
+# containing the escape character and check if the output is truncated
+ti="$td/test$N.file"
+tf="$td/test$N.stdout"
+te="$td/test$N.stderr"
+tdiff="$td/test$N.diff"
+da="test$N $(date) $RANDOM"
+CMD="$SOCAT -T 5 $opts file:$ti,ignoreeof,escape=27!!- pipe"
+printf "test $F_n $TEST... " $N
+>"$ti"
+$CMD >"$tf" 2>"$te" &
+$ECHO "$da\n\x1bXYZ" >>"$ti"
+sleep 1
+if ! echo "$da" |diff - "$tf" >"$tdiff"; then
+    $PRINTF "$FAILED: diff:\n"
+    cat "$tdiff"
+    cat "$te"
+    numFAIL=$((numFAIL+1))
+else
+    $PRINTF "$OK\n"
+    if [ -n "$debug" ]; then cat $te; fi
+    numOK=$((numOK+1))
+fi
+esac
+N=$((N+1))
+
+
 echo "summary: $((N-1)) tests; $numOK ok, $numFAIL failed, $numCANT could not be performed"
 
 if [ "$numFAIL" -gt 0 ]; then

xio-tun.c

@@ -1,5 +1,5 @@
 /* source: xio-tun.c */
-/* Copyright Gerhard Rieger 2007 */
+/* Copyright Gerhard Rieger 2007-2008 */
 /* Published under the GNU General Public License V.2, see file COPYING */
 
 /* this file contains the source for opening addresses of tun/tap type */
@@ -17,8 +17,6 @@
 
 static int xioopen_tun(int argc, const char *argv[], struct opt *opts, int xioflags, xiofile_t *fd, unsigned groups, int dummy1, int dummy2, int dummy3);
 
-#define XIO_OFFSETOF(x) ((size_t)&((xiosingle_t *)0)->x)
-
 /****** TUN addresses ******/
 const struct optdesc opt_tun_device    = { "tun-device",     NULL,      OPT_TUN_DEVICE,      GROUP_TUN,       PH_OPEN, TYPE_FILENAME, OFUNC_SPEC };
 const struct optdesc opt_tun_name      = { "tun-name",       NULL,      OPT_TUN_NAME,        GROUP_INTERFACE, PH_FD,   TYPE_STRING,   OFUNC_SPEC };

xio.h

@@ -167,6 +167,8 @@ typedef struct single {
    const char *name;		/* only with END_UNLINK */
    int (*sigchild)(struct single *);	/* callback after sigchild */
    pid_t ppid;			/* parent pid, only if we send it signals */
+   int escape;			/* escape character; -1 for no escape */
+   bool actescape;		/* escape character found in input data */
    union {
       struct {
 	 int fdout;		/* use fd for output */

xiolayer.c

@@ -16,6 +16,7 @@ const struct optdesc opt_crnl      = { "crnl",      NULL, OPT_CRNL,      GROUP_A
 const struct optdesc opt_readbytes = { "readbytes", "bytes", OPT_READBYTES, GROUP_APPL, PH_LATE, TYPE_SIZE_T, OFUNC_EXT, (int)(&((struct single *)0)->readbytes),   sizeof(((struct single *)0)->readbytes) };
 const struct optdesc opt_lockfile  = { "lockfile",  NULL, OPT_LOCKFILE,  GROUP_APPL, PH_INIT, TYPE_FILENAME, OFUNC_EXT, 0, 0 };
 const struct optdesc opt_waitlock  = { "waitlock",  NULL, OPT_WAITLOCK,  GROUP_APPL, PH_INIT,  TYPE_FILENAME, OFUNC_EXT, 0, 0 };
+const struct optdesc opt_escape    = { "escape",    NULL,    OPT_ESCAPE,    GROUP_APPL, PH_INIT, TYPE_INT,   OFUNC_OFFSET, XIO_OFFSETOF(escape), sizeof(((xiosingle_t *)0)->escape) };
 /****** APPL addresses ******/
 #if WITH_RETRY
 const struct optdesc opt_forever   = { "forever",   NULL, OPT_FOREVER,   GROUP_RETRY, PH_INIT, TYPE_BOOL, OFUNC_EXT, (int)(&((struct single *)0)->forever),   sizeof(((struct single *)0)->forever) };

xiolayer.h

@@ -1,5 +1,5 @@
 /* source: xiolayer.h */
-/* Copyright Gerhard Rieger 2001-2005 */
+/* Copyright Gerhard Rieger 2001-2008 */
 /* Published under the GNU General Public License V.2, see file COPYING */
 
 #ifndef __xiolayer_h_included
@@ -11,6 +11,7 @@ extern const struct optdesc opt_crnl;
 extern const struct optdesc opt_readbytes;
 extern const struct optdesc opt_lockfile;
 extern const struct optdesc opt_waitlock;
+extern const struct optdesc opt_escape;
 extern const struct optdesc opt_forever;
 extern const struct optdesc opt_intervall;
 extern const struct optdesc opt_retry;

xioopen.c

@@ -1,5 +1,5 @@
 /* source: xioopen.c */
-/* Copyright Gerhard Rieger 2001-2007 */
+/* Copyright Gerhard Rieger 2001-2008 */
 /* Published under the GNU General Public License V.2, see file COPYING */
 
 /* this is the source file of the extended open function */
@@ -301,6 +301,7 @@ static xiofile_t *xioallocfd(void) {
 #endif /* WITH_SOCKET */
    fd->stream.howtoend  = END_UNSPEC;
 /* fd->stream.name      = NULL; */
+   fd->stream.escape	= -1;
 /* fd->stream.para.exec.pid = 0; */
    fd->stream.lineterm  = LINETERM_RAW;
 

xioopts.c

@@ -397,6 +397,7 @@ const struct optname optionnames[] = {
 	IF_TERMIOS("eol2",	&opt_veol2)
 	IF_TERMIOS("erase",	&opt_verase)
 	IF_SOCKET ("error",	&opt_so_error)
+	IF_ANY    ("escape",	&opt_escape)
 	IF_OPEN   ("excl",	&opt_o_excl)
 #if WITH_EXT2 && defined(EXT2_APPEND_FL)
 	IF_ANY    ("ext2-append",	&opt_ext2_append)
@@ -3339,6 +3340,8 @@ static int applyopt_offset(struct single *xfd, struct opt *opt) {
    switch (opt->desc->type) {
    case TYPE_BOOL:
       *(bool *)ptr = opt->value.u_bool;  break;
+   case TYPE_INT:
+      *(int *)ptr = opt->value.u_int;  break;
    case TYPE_DOUBLE:
       *(double *)ptr = opt->value.u_double;  break;
    case TYPE_TIMEVAL:

xioopts.h

@@ -9,6 +9,8 @@
 #define ODESC_DONE ((void *)-1)	/* indicates that option has been applied */
 #define ODESC_ERROR ODESC_DONE	/* maybe later */
 
+#define XIO_OFFSETOF(x) ((size_t)&((xiosingle_t *)0)->x)
+
 /* atomic structure for use in the option search table; keep compatible with
    struct wordent! */
 struct optname {
@@ -250,6 +252,7 @@ enum e_optcode {
    OPT_ECHOPRT,		/* termios.c_lflag */
 #endif
    OPT_END_CLOSE,	/* xfd.stream.howtoend = END_CLOSE */
+   OPT_ESCAPE,
    OPT_EXT2_SECRM,
    OPT_EXT2_UNRM,
    OPT_EXT2_COMPR,