-/* packet-pop.c
+/* packet-telnet.c
* Routines for telnet packet dissection
* Copyright 1999, Richard Sharpe <rsharpe@ns.aus.com>
*
- *
+ * $Id: packet-telnet.c,v 1.24 2001/01/25 06:14:14 guy Exp $
*
* Ethereal - Network traffic analyzer
- * By Gerald Combs <gerald@unicom.net>
+ * By Gerald Combs <gerald@zing.org>
* Copyright 1998 Gerald Combs
*
* Copied from packet-pop.c
#include <string.h>
#include <glib.h>
#include "packet.h"
-#include "etypes.h"
+#include "strutil.h"
+
+static int proto_telnet = -1;
+
+static gint ett_telnet = -1;
+static gint ett_telnet_subopt = -1;
/* Some defines for Telnet */
+#define TCP_PORT_TELNET 23
+
#define TN_IAC 255
#define TN_DONT 254
#define TN_DO 253
#define TN_SUSP 237
#define TN_EOF 236
-char *options[] = {
+static const char *options[] = {
"Binary Transmission",
"Echo",
"Reconnection",
"TN3270E"
};
-extern packet_info pi;
+#define NOPTIONS (sizeof options / sizeof options[0])
-void telnet_sub_option(proto_tree *telnet_tree, char *rr, int *i, int offset, int max_data)
+static int
+telnet_sub_option(proto_tree *telnet_tree, tvbuff_t *tvb, int start_offset)
{
proto_tree *ti, *option_tree;
- int subneg_len, req, si1, not_found = 1;
- volatile int i1;
- char *opt, sub_opt_data[1500];
+ int offset = start_offset;
+ guint8 opt_byte;
+ int subneg_len, req;
+ const u_char *opt;
+ guint len;
- memset(sub_opt_data, '\0', sizeof(sub_opt_data));
+ offset += 2; /* skip IAC and SB */
/* Figure out the option and type */
-
- opt = options[(unsigned int)rr[*i]];
- req = (unsigned int)rr[*i + 1];
-
- i1 = *i + 2; si1 = i1;
- while ((i1 < max_data) && (not_found)) {
-
- if ((unsigned char)rr[i1] == (unsigned char)TN_IAC)
- not_found = 0;
- else
- i1++;
-
+ opt_byte = tvb_get_guint8(tvb, offset);
+ if (opt_byte > NOPTIONS)
+ opt = "<unknown option>";
+ else
+ opt = options[opt_byte];
+ offset++;
+ req = tvb_get_guint8(tvb, offset);
+ 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 = i1 - *i + 2;
+ subneg_len = offset - start_offset;
- ti = proto_tree_add_item(telnet_tree, offset, subneg_len, "Suboption Begin: %s", opt);
+ ti = proto_tree_add_text(telnet_tree, tvb, start_offset, subneg_len,
+ "Suboption Begin: %s", opt);
- option_tree = proto_tree_new();
+ option_tree = proto_item_add_subtree(ti, ett_telnet_subopt);
- proto_item_add_subtree(ti, option_tree, ETT_TELNET_SUBOPT);
-
- proto_tree_add_item(option_tree, offset + 2, subneg_len - 2, "%s %s", (req ? "Send your" : "Here's my"), opt);
+ 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 */
-
- memcpy(sub_opt_data, rr + *i + 2, subneg_len - 2);
- proto_tree_add_item(option_tree, offset + 4, subneg_len - 4, "Value: %s", format_text(sub_opt_data, subneg_len - 4));
- *i += subneg_len - 2;
-
+ 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));
}
- else {
-
- *i += subneg_len - 2;
+ return offset;
+}
- }
+static int
+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} */
+ opt_byte = tvb_get_guint8(tvb, offset);
+ if (opt_byte > NOPTIONS)
+ opt = "<unknown option>";
+ else
+ opt = options[opt_byte];
+ offset++;
+
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 3,
+ "Command: %s %s", type, opt);
+ return offset;
}
-void telnet_command(proto_tree *telnet_tree, char *rr, int *i, int offset, int max_data)
+static int
+telnet_command(proto_tree *telnet_tree, tvbuff_t *tvb, int start_offset)
{
- char *opt;
+ int offset = start_offset;
+ u_char optcode;
- switch((unsigned char)rr[*i]) {
+ offset += 1; /* skip IAC */
+ optcode = tvb_get_guint8(tvb, offset);
+ offset++;
+ switch(optcode) {
case TN_EOF:
-
- proto_tree_add_item(telnet_tree, offset, 2, "Command: End of File");
- (*i)++;
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
+ "Command: End of File");
break;
case TN_SUSP:
-
- proto_tree_add_item(telnet_tree, offset, 2, "Command: Suspend Current Process");
- (*i)++;
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
+ "Command: Suspend Current Process");
break;
case TN_ABORT:
-
- proto_tree_add_item(telnet_tree, offset, 2, "Command: Abort Process");
- (*i)++;
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
+ "Command: Abort Process");
break;
case TN_EOR:
-
- proto_tree_add_item(telnet_tree, offset, 2, "Command: End of Record");
- (*i)++;
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
+ "Command: End of Record");
break;
case TN_SE:
-
- proto_tree_add_item(telnet_tree, offset, 2, "Command: Suboption End");
- (*i)++;
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
+ "Command: Suboption End");
break;
case TN_NOP:
-
- proto_tree_add_item(telnet_tree, offset, 2, "Command: No Operation");
- (*i)++;
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
+ "Command: No Operation");
break;
case TN_DM:
-
- proto_tree_add_item(telnet_tree, offset, 2, "Command: Data Mark");
- (*i)++;
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
+ "Command: Data Mark");
break;
case TN_BRK:
-
- proto_tree_add_item(telnet_tree, offset, 2, "Command: Break");
- (*i)++;
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
+ "Command: Break");
break;
case TN_IP:
-
- proto_tree_add_item(telnet_tree, offset, 2, "Command: Interrupt Process");
- (*i)++;
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
+ "Command: Interrupt Process");
break;
case TN_AO:
-
- proto_tree_add_item(telnet_tree, offset, 2, "Command: Abort Output");
- (*i)++;
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
+ "Command: Abort Output");
break;
case TN_AYT:
-
- proto_tree_add_item(telnet_tree, offset, 2, "Command: Are You There?");
- (*i)++;
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
+ "Command: Are You There?");
break;
case TN_EC:
-
- proto_tree_add_item(telnet_tree, offset, 2, "Command: Escape Character");
- (*i)++;
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
+ "Command: Escape Character");
break;
case TN_EL:
-
- proto_tree_add_item(telnet_tree, offset, 2, "Command: Erase Line");
- (*i)++;
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
+ "Command: Erase Line");
break;
case TN_GA:
-
- proto_tree_add_item(telnet_tree, offset, 2, "Command: Go Ahead");
- (*i)++;
+ proto_tree_add_text(telnet_tree, tvb, start_offset, 2,
+ "Command: Go Ahead");
break;
case TN_SB:
-
- (*i)++;
- telnet_sub_option(telnet_tree, rr, i, offset, max_data);
+ offset = telnet_sub_option(telnet_tree, tvb, start_offset);
break;
case TN_WILL:
-
- if (rr[*i + 1] > (sizeof(options)/sizeof(char *)))
- opt = "<unknown option>";
- else
- opt = options[(unsigned int)rr[*i + 1]];
-
- proto_tree_add_item(telnet_tree, offset, 3, "Command: Will %s", opt);
- *i += 2; /* skip two chars */
+ offset = telnet_will_wont_do_dont(telnet_tree, tvb, start_offset,
+ "Will");
break;
case TN_WONT:
-
- if (rr[*i + 1] > (sizeof(options)/sizeof(char *)))
- opt = "<unknown option>";
- else
- opt = options[(unsigned int)rr[*i + 1]];
-
- proto_tree_add_item(telnet_tree, offset, 3, "Command: Won't %s", opt);
- *i += 2; /* skip two chars */
+ offset = telnet_will_wont_do_dont(telnet_tree, tvb, start_offset,
+ "Won't");
break;
case TN_DO:
-
- if (rr[*i + 1] > (sizeof(options)/sizeof(char *)))
- opt = "<unknown option>";
- else
- opt = options[(unsigned int)rr[*i + 1]];
-
- proto_tree_add_item(telnet_tree, offset, 3, "Command: Do %s", opt);
- *i += 2; /* skip two chars */
+ offset = telnet_will_wont_do_dont(telnet_tree, tvb, start_offset,
+ "Do");
break;
case TN_DONT:
-
- if (rr[*i + 1] > (sizeof(options)/sizeof(char *)))
- opt = "<unknown option>";
- else
- opt = options[(unsigned int)rr[*i + 1]];
-
- proto_tree_add_item(telnet_tree, offset, 3, "Command: Don't %s", opt);
- *i += 2; /* skip two chars */
+ offset = telnet_will_wont_do_dont(telnet_tree, tvb, start_offset,
+ "Don't");
break;
-
}
+ return offset;
}
-void
-dissect_telnet(const u_char *pd, int offset, frame_data *fd, proto_tree *tree, int max_data)
+static void
+telnet_add_text(proto_tree *tree, tvbuff_t *tvb, int offset, int len)
{
- proto_tree *telnet_tree, *ti;
- gchar rr[1500];
- int i1;
- int i2;
-
- memset(rr, '\0', sizeof(rr));
-
- if (check_col(fd, COL_PROTOCOL))
- col_add_str(fd, COL_PROTOCOL, "TELNET");
+ 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;
+ }
+}
- if (check_col(fd, COL_INFO)) {
+static void
+dissect_telnet(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+ proto_tree *telnet_tree, *ti;
- col_add_fstr(fd, COL_INFO, "Telnet Data ...");
+ if (check_col(pinfo->fd, COL_PROTOCOL))
+ col_set_str(pinfo->fd, COL_PROTOCOL, "TELNET");
- }
+ if (check_col(pinfo->fd, COL_INFO))
+ col_add_fstr(pinfo->fd, COL_INFO, "Telnet Data ...");
if (tree) {
-
- char data[1500];
- int i3;
-
- memset(data, '\0', sizeof(data));
-
- memcpy(rr, pd + offset, max_data);
-
- ti = proto_tree_add_item(tree, offset, END_OF_FRAME,
- "Telnet Protocol");
- telnet_tree = proto_tree_new();
- proto_item_add_subtree(ti, telnet_tree, ETT_TELNET);
-
- i1 = i2 = i3 = 0;
-
- while (i1 < max_data) {
-
- if ((unsigned char)rr[i1] == (unsigned char)TN_IAC) {
-
- if (strlen(data) > 0) {
-
- proto_tree_add_item(telnet_tree, offset + i2, strlen(data), "Data: %s", format_text(data, strlen(data)));
- memset(data, '\0', sizeof(data));
- i3 = 0;
-
- }
+ gint offset = 0;
+ guint len;
+ int data_len;
+ gint iac_offset;
+
+ 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);
+
+ /*
+ * Scan through the buffer looking for an IAC byte.
+ */
+ 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, a line at a time.
+ */
+ data_len = iac_offset - offset;
+ if (data_len > 0)
+ telnet_add_text(telnet_tree, tvb, offset, data_len);
- i1++;
- telnet_command(telnet_tree, rr, &i1, offset + i1 - 1, max_data);
- i2 = i1;
-
+ /*
+ * Now interpret the command.
+ */
+ offset = telnet_command(telnet_tree, tvb, iac_offset);
}
else {
-
- data[i3] = rr[i1];
- i3++;
- i1++;
-
-
+ /*
+ * 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;
}
}
-
- if (strlen(data) > 0) { /* Still some data to add */
-
- proto_tree_add_item(telnet_tree, offset + i2, strlen(data), "Data: %s", format_text(data, strlen(data)));
-
- }
-
}
-
}
+void
+proto_register_telnet(void)
+{
+/* static hf_register_info hf[] = {
+ { &variable,
+ { "Name", "telnet.abbreviation", TYPE, VALS_POINTER }},
+ };*/
+ static gint *ett[] = {
+ &ett_telnet,
+ &ett_telnet_subopt,
+ };
+
+ 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,
+ proto_telnet);
+}
git.samba.org / metze / wireshark / wip.git / blobdiff