* Routines for telnet packet dissection
* Copyright 1999, Richard Sharpe <rsharpe@ns.aus.com>
*
- * $Id: packet-telnet.c,v 1.12 2000/05/11 08:15:52 gram Exp $
+ * $Id: packet-telnet.c,v 1.24 2001/01/25 06:14:14 guy Exp $
*
* Ethereal - Network traffic analyzer
* By Gerald Combs <gerald@zing.org>
#include <string.h>
#include <glib.h>
#include "packet.h"
+#include "strutil.h"
static int proto_telnet = -1;
#define NOPTIONS (sizeof options / sizeof options[0])
static int
-telnet_sub_option(proto_tree *telnet_tree, const u_char *pd,
- int start_offset)
+telnet_sub_option(proto_tree *telnet_tree, tvbuff_t *tvb, int start_offset)
{
proto_tree *ti, *option_tree;
int offset = start_offset;
+ guint8 opt_byte;
int subneg_len, req;
- gboolean not_found = TRUE;
const u_char *opt;
+ guint len;
offset += 2; /* skip IAC and SB */
/* Figure out the option and type */
- if (pd[offset] > NOPTIONS)
+ opt_byte = tvb_get_guint8(tvb, offset);
+ if (opt_byte > NOPTIONS)
opt = "<unknown option>";
else
- opt = options[pd[offset]];
+ opt = options[opt_byte];
offset++;
- req = pd[offset];
+ req = tvb_get_guint8(tvb, offset);
offset++;
- while (offset < pi.captured_len && not_found) {
- if (pd[offset] == TN_IAC)
- not_found = FALSE;
- else
- offset++;
+ /* Search for an IAC. */
+ len = tvb_length_remaining(tvb, offset);
+ offset = tvb_find_guint8(tvb, offset, len, TN_IAC);
+ if (offset == -1) {
+ /* None found - run to the end of the packet. */
+ offset += len;
}
subneg_len = offset - start_offset;
- ti = proto_tree_add_text(telnet_tree, NullTVB, start_offset, subneg_len,
+ ti = proto_tree_add_text(telnet_tree, tvb, start_offset, subneg_len,
"Suboption Begin: %s", opt);
option_tree = proto_item_add_subtree(ti, ett_telnet_subopt);
- proto_tree_add_text(option_tree, NullTVB, start_offset + 2, 2,
+ proto_tree_add_text(option_tree, tvb, start_offset + 2, 2,
"%s %s", (req ? "Send your" : "Here's my"), opt);
if (req == 0) { /* Add the value */
- proto_tree_add_text(option_tree, NullTVB, start_offset + 4, subneg_len - 4,
- "Value: %s", format_text(&pd[start_offset + 4], subneg_len - 4));
+ proto_tree_add_text(option_tree, tvb, start_offset + 4, subneg_len - 4,
+ "Value: %s", tvb_format_text(tvb, start_offset + 4, subneg_len - 4));
}
return offset;
}
static int
-telnet_will_wont_do_dont(proto_tree *telnet_tree, const u_char *pd,
+telnet_will_wont_do_dont(proto_tree *telnet_tree, tvbuff_t *tvb,
int start_offset, char *type)
{
int offset = start_offset;
+ guint8 opt_byte;
const char *opt;
offset += 2; /* skip IAC and WILL,WONT,DO,DONT} */
- if (pd[offset] > NOPTIONS)
+ opt_byte = tvb_get_guint8(tvb, offset);
+ if (opt_byte > NOPTIONS)
opt = "<unknown option>";
else
- opt = options[pd[offset]];
+ opt = options[opt_byte];
offset++;
- proto_tree_add_text(telnet_tree, NullTVB, start_offset, 3,
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 3,
"Command: %s %s", type, opt);
return offset;
}
static int
-telnet_command(proto_tree *telnet_tree, const u_char *pd, int start_offset)
+telnet_command(proto_tree *telnet_tree, tvbuff_t *tvb, int start_offset)
{
int offset = start_offset;
u_char optcode;
offset += 1; /* skip IAC */
- optcode = pd[offset];
+ optcode = tvb_get_guint8(tvb, offset);
offset++;
switch(optcode) {
case TN_EOF:
- proto_tree_add_text(telnet_tree, NullTVB, start_offset, 2,
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
"Command: End of File");
break;
case TN_SUSP:
- proto_tree_add_text(telnet_tree, NullTVB, start_offset, 2,
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
"Command: Suspend Current Process");
break;
case TN_ABORT:
- proto_tree_add_text(telnet_tree, NullTVB, start_offset, 2,
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
"Command: Abort Process");
break;
case TN_EOR:
- proto_tree_add_text(telnet_tree, NullTVB, start_offset, 2,
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
"Command: End of Record");
break;
case TN_SE:
- proto_tree_add_text(telnet_tree, NullTVB, start_offset, 2,
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
"Command: Suboption End");
break;
case TN_NOP:
- proto_tree_add_text(telnet_tree, NullTVB, start_offset, 2,
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
"Command: No Operation");
break;
case TN_DM:
- proto_tree_add_text(telnet_tree, NullTVB, start_offset, 2,
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
"Command: Data Mark");
break;
case TN_BRK:
- proto_tree_add_text(telnet_tree, NullTVB, start_offset, 2,
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
"Command: Break");
break;
case TN_IP:
- proto_tree_add_text(telnet_tree, NullTVB, start_offset, 2,
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
"Command: Interrupt Process");
break;
case TN_AO:
- proto_tree_add_text(telnet_tree, NullTVB, start_offset, 2,
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
"Command: Abort Output");
break;
case TN_AYT:
- proto_tree_add_text(telnet_tree, NullTVB, start_offset, 2,
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
"Command: Are You There?");
break;
case TN_EC:
- proto_tree_add_text(telnet_tree, NullTVB, start_offset, 2,
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
"Command: Escape Character");
break;
case TN_EL:
- proto_tree_add_text(telnet_tree, NullTVB, start_offset, 2,
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
"Command: Erase Line");
break;
case TN_GA:
- proto_tree_add_text(telnet_tree, NullTVB, start_offset, 2,
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
"Command: Go Ahead");
break;
case TN_SB:
- offset = telnet_sub_option(telnet_tree, pd, start_offset);
+ offset = telnet_sub_option(telnet_tree, tvb, start_offset);
break;
case TN_WILL:
- offset = telnet_will_wont_do_dont(telnet_tree, pd, start_offset,
+ offset = telnet_will_wont_do_dont(telnet_tree, tvb, start_offset,
"Will");
break;
case TN_WONT:
- offset = telnet_will_wont_do_dont(telnet_tree, pd, start_offset,
+ offset = telnet_will_wont_do_dont(telnet_tree, tvb, start_offset,
"Won't");
break;
case TN_DO:
- offset = telnet_will_wont_do_dont(telnet_tree, pd, start_offset,
+ offset = telnet_will_wont_do_dont(telnet_tree, tvb, start_offset,
"Do");
break;
case TN_DONT:
- offset = telnet_will_wont_do_dont(telnet_tree, pd, start_offset,
+ offset = telnet_will_wont_do_dont(telnet_tree, tvb, start_offset,
"Don't");
break;
}
}
static void
-dissect_telnet(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
+telnet_add_text(proto_tree *tree, tvbuff_t *tvb, int offset, int len)
+{
+ gint next_offset;
+ int linelen;
+ guint8 c;
+ gboolean last_char_was_cr;
+
+ while (len != 0 && tvb_offset_exists(tvb, offset)) {
+ /*
+ * Find the end of the line.
+ */
+ linelen = tvb_find_line_end(tvb, offset, len, &next_offset);
+ len -= next_offset - offset; /* subtract out the line's characters */
+
+ /*
+ * In Telnet, CR NUL is the way you send a CR by itself in the
+ * default ASCII mode; don't treat CR by itself as a line ending,
+ * treat only CR NUL, CR LF, or LF by itself as a line ending.
+ */
+ if (next_offset == offset + linelen + 1 && len >= 1) {
+ /*
+ * Well, we saw a one-character line ending, so either it's a CR
+ * or an LF; we have at least two characters left, including the
+ * CR.
+ *
+ * If the line ending is a CR, skip all subsequent CRs; at
+ * least one capture appeared to have multiple CRs at the end of
+ * a line.
+ */
+ if (tvb_get_guint8(tvb, offset + linelen) == '\r') {
+ last_char_was_cr = TRUE;
+ while (len != 0 && tvb_offset_exists(tvb, next_offset)) {
+ c = tvb_get_guint8(tvb, next_offset);
+ next_offset++; /* skip over that character */
+ len--;
+ if (c == '\n' || (c == '\0' && last_char_was_cr)) {
+ /*
+ * LF is a line ending, whether preceded by CR or not.
+ * NUL is a line ending if preceded by CR.
+ */
+ break;
+ }
+ last_char_was_cr = (c == '\r');
+ }
+ }
+ }
+
+ /*
+ * Now compute the length of the line *including* the end-of-line
+ * indication, if any; we display it all.
+ */
+ linelen = next_offset - offset;
+
+ proto_tree_add_text(tree, tvb, offset, linelen,
+ "Data: %s",
+ tvb_format_text(tvb, offset, linelen));
+ offset = next_offset;
+ }
+}
+
+static void
+dissect_telnet(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
proto_tree *telnet_tree, *ti;
- if (check_col(fd, COL_PROTOCOL))
- col_add_str(fd, COL_PROTOCOL, "TELNET");
+ if (check_col(pinfo->fd, COL_PROTOCOL))
+ col_set_str(pinfo->fd, COL_PROTOCOL, "TELNET");
- if (check_col(fd, COL_INFO))
- col_add_fstr(fd, COL_INFO, "Telnet Data ...");
+ if (check_col(pinfo->fd, COL_INFO))
+ col_add_fstr(pinfo->fd, COL_INFO, "Telnet Data ...");
if (tree) {
- int data_offset;
+ gint offset = 0;
+ guint len;
int data_len;
+ gint iac_offset;
- ti = proto_tree_add_item(tree, proto_telnet, NullTVB, offset, END_OF_FRAME, NULL);
+ ti = proto_tree_add_item(tree, proto_telnet, tvb, offset,
+ tvb_length_remaining(tvb, offset), FALSE);
telnet_tree = proto_item_add_subtree(ti, ett_telnet);
- data_offset = offset;
- data_len = 0;
-
/*
* Scan through the buffer looking for an IAC byte.
*/
- while (offset < pi.captured_len) {
- if (pd[offset] == TN_IAC) {
+ while ((len = tvb_length_remaining(tvb, offset)) > 0) {
+ iac_offset = tvb_find_guint8(tvb, offset, len, TN_IAC);
+ if (iac_offset != -1) {
/*
* We found an IAC byte.
* If there's any data before it, add that data to the
- * tree.
+ * tree, a line at a time.
*/
- if (data_len > 0) {
- proto_tree_add_text(telnet_tree, NullTVB, data_offset, data_len,
- "Data: %s", format_text(&pd[data_offset], data_len));
- data_len = 0;
- data_offset = offset;
- }
+ data_len = iac_offset - offset;
+ if (data_len > 0)
+ telnet_add_text(telnet_tree, tvb, offset, data_len);
/*
* Now interpret the command.
*/
- offset = telnet_command(telnet_tree, pd, offset);
- data_offset = offset;
+ offset = telnet_command(telnet_tree, tvb, iac_offset);
}
else {
- data_len++;
- offset++;
+ /*
+ * We found no IAC byte, so what remains in the buffer
+ * is the last of the data in the packet.
+ * Add it to the tree, a line at a time, and then quit.
+ */
+ telnet_add_text(telnet_tree, tvb, offset, len);
+ break;
}
}
-
- /*
- * We've reached the end of the buffer.
- * If there's any data left, add it to the tree.
- */
- if (data_len > 0) {
- proto_tree_add_text(telnet_tree, NullTVB, data_offset, data_len, "Data: %s",
- format_text(&pd[data_offset], data_len));
- }
}
}
&ett_telnet_subopt,
};
- proto_telnet = proto_register_protocol("Telnet", "telnet");
+ proto_telnet = proto_register_protocol("Telnet", "TELNET", "telnet");
/* proto_register_field_array(proto_telnet, hf, array_length(hf));*/
proto_register_subtree_array(ett, array_length(ett));
}
void
proto_reg_handoff_telnet(void)
{
- dissector_add("tcp.port", TCP_PORT_TELNET, dissect_telnet);
+ dissector_add("tcp.port", TCP_PORT_TELNET, dissect_telnet,
+ proto_telnet);
}
git.samba.org / metze / wireshark / wip.git / blobdiff