1 |
stdarg |
1.1 |
#include <eggdrop/eggdrop.h> |
2 |
stdarg |
1.3 |
#include "core_config.h" |
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stdarg |
1.1 |
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4 |
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/* Possible states of the connection. */ |
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#define STATE_RESOLVE 0 |
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#define STATE_NICKNAME 1 |
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#define STATE_PASSWORD 2 |
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#define STATE_PARTYLINE 3 |
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/* Telnet strings for controlling echo behavior. */ |
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#define TELNET_ECHO 1 |
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#define TELNET_AYT 246 |
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#define TELNET_WILL 251 |
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#define TELNET_WONT 252 |
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#define TELNET_DO 253 |
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#define TELNET_DONT 254 |
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#define TELNET_CMD 255 |
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#define TELNET_ECHO_OFF "\377\373\001" |
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#define TELNET_ECHO_ON "\377\374\001" |
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#define TFLAG_ECHO 1 |
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/* Flags for sessions. */ |
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#define STEALTH_LOGIN 1 |
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typedef struct { |
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/* Who we're connected to. */ |
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user_t *user; |
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char *nick, *ident, *host, *ip; |
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int port; |
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int idx; |
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int pid; |
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/* Flags for this connection. */ |
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int flags; |
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/* Connection state we're in. */ |
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int state, count; |
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} telnet_session_t; |
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static int telnet_idx = -1; |
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static int telnet_port = 0; |
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static void kill_session(telnet_session_t *session); |
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static int telnet_on_newclient(void *client_data, int idx, int newidx, const char *peer_ip, int peer_port); |
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static int telnet_on_read(void *client_data, int idx, char *data, int len); |
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static int telnet_on_eof(void *client_data, int idx, int err, const char *errmsg); |
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static int telnet_filter_read(void *client_data, int idx, char *data, int len); |
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static int telnet_filter_write(void *client_data, int idx, const char *data, int len); |
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static int telnet_filter_delete(void *client_data, int idx); |
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static int ident_result(void *client_data, const char *ip, int port, const char *reply); |
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static int dns_result(void *client_data, const char *ip, const char *host); |
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static int process_results(telnet_session_t *session); |
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static sockbuf_handler_t server_handler = { |
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"telnet server", |
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NULL, NULL, telnet_on_newclient, |
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NULL, NULL |
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}; |
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#define TELNET_FILTER_LEVEL SOCKBUF_LEVEL_TEXT_ALTERATION |
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static sockbuf_filter_t telnet_filter = { |
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"telnet filter", TELNET_FILTER_LEVEL, |
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NULL, NULL, NULL, |
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telnet_filter_read, telnet_filter_write, NULL, |
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NULL, telnet_filter_delete |
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}; |
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static sockbuf_handler_t client_handler = { |
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"telnet", |
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NULL, telnet_on_eof, NULL, |
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telnet_on_read, NULL |
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}; |
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int telnet_init() |
80 |
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{ |
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/* Open our listening socket. */ |
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stdarg |
1.3 |
telnet_idx = egg_server(core_config.telnet_vhost, core_config.telnet_port, &telnet_port); |
83 |
stdarg |
1.1 |
sockbuf_set_handler(telnet_idx, &server_handler, NULL); |
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return(0); |
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} |
86 |
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static void kill_session(telnet_session_t *session) |
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{ |
89 |
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sockbuf_delete(session->idx); |
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if (session->ip) free(session->ip); |
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if (session->host) free(session->host); |
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if (session->ident) free(session->ident); |
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if (session->nick) free(session->nick); |
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free(session); |
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} |
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static int telnet_on_newclient(void *client_data, int idx, int newidx, const char *peer_ip, int peer_port) |
98 |
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{ |
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telnet_session_t *session; |
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int *flags; |
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102 |
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session = calloc(1, sizeof(*session)); |
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session->ip = strdup(peer_ip); |
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session->port = peer_port; |
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session->idx = newidx; |
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sockbuf_set_handler(newidx, &client_handler, session); |
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flags = calloc(1, sizeof(*flags)); |
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sockbuf_attach_filter(newidx, &telnet_filter, flags); |
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linemode_on(newidx); |
111 |
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/* Stealth logins are where we don't say anything until we know they |
113 |
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* are a valid user. */ |
114 |
stdarg |
1.3 |
if (core_config.telnet_stealth) { |
115 |
stdarg |
1.1 |
session->state = STATE_RESOLVE; |
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} |
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else { |
118 |
stdarg |
1.2 |
sockbuf_write(newidx, "\r\nPlease enter your nickname.\r\n", -1); |
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stdarg |
1.1 |
session->state = STATE_NICKNAME; |
120 |
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session->count = 0; |
121 |
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} |
122 |
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/* Start lookups. */ |
124 |
stdarg |
1.3 |
egg_ident_lookup(peer_ip, peer_port, telnet_port, -1, ident_result, session); |
125 |
stdarg |
1.2 |
egg_dns_reverse(peer_ip, -1, dns_result, session); |
126 |
stdarg |
1.1 |
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127 |
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return(0); |
128 |
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} |
129 |
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130 |
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static int ident_result(void *client_data, const char *ip, int port, const char *reply) |
131 |
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{ |
132 |
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telnet_session_t *session = client_data; |
133 |
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134 |
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if (reply) session->ident = strdup(reply); |
135 |
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else session->ident = strdup("~telnet"); |
136 |
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process_results(session); |
137 |
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return(0); |
138 |
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} |
139 |
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140 |
stdarg |
1.2 |
static int dns_result(void *client_data, const char *ip, const char *host) |
141 |
stdarg |
1.1 |
{ |
142 |
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telnet_session_t *session = client_data; |
143 |
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144 |
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session->host = strdup(host); |
145 |
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process_results(session); |
146 |
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return(0); |
147 |
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} |
148 |
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149 |
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static int process_results(telnet_session_t *session) |
150 |
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{ |
151 |
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char *fakehost; |
152 |
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153 |
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if (!session->ident || !session->host) return(0); |
154 |
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155 |
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if (session->state == STATE_PARTYLINE) { |
156 |
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partyline_update_info(session->pid, session->ident, session->host); |
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return(0); |
158 |
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} |
159 |
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if (session->flags & STEALTH_LOGIN) { |
160 |
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fakehost = msprintf("-telnet!%s@%s", session->ident, session->host); |
161 |
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if (!user_lookup_by_irchost(fakehost)) { |
162 |
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kill_session(session); |
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return(0); |
164 |
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} |
165 |
stdarg |
1.2 |
sockbuf_write(session->idx, "\r\nPlease enter your nickname.\r\n", -1); |
166 |
stdarg |
1.1 |
session->state = STATE_NICKNAME; |
167 |
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} |
168 |
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return(0); |
169 |
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} |
170 |
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171 |
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static int telnet_on_read(void *client_data, int idx, char *data, int len) |
172 |
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{ |
173 |
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telnet_session_t *session = client_data; |
174 |
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175 |
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switch (session->state) { |
176 |
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case STATE_PARTYLINE: |
177 |
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partyline_on_input(session->pid, data, len); |
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break; |
179 |
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case STATE_NICKNAME: |
180 |
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session->nick = strdup(data); |
181 |
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session->state = STATE_PASSWORD; |
182 |
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sockbuf_write(session->idx, TELNET_ECHO_OFF, -1); |
183 |
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sockbuf_write(session->idx, "Please enter your password.\r\n", -1); |
184 |
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break; |
185 |
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case STATE_PASSWORD: |
186 |
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sockbuf_write(session->idx, TELNET_ECHO_ON, -1); |
187 |
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session->user = user_lookup_authed(session->nick, data); |
188 |
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if (!session->user) { |
189 |
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sockbuf_write(session->idx, "Invalid username/password.\r\n\r\n", -1); |
190 |
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session->count++; |
191 |
stdarg |
1.3 |
if (session->count > core_config.telnet_max_retries) { |
192 |
stdarg |
1.1 |
kill_session(session); |
193 |
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break; |
194 |
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} |
195 |
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free(session->nick); |
196 |
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session->nick = NULL; |
197 |
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sockbuf_write(session->idx, "Please enter your nickname.\r\n", -1); |
198 |
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session->state = STATE_NICKNAME; |
199 |
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} |
200 |
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else { |
201 |
stdarg |
1.2 |
session->pid = partyline_connect(session->idx, -1, session->user, session->nick, session->ident ? session->ident : "~telnet", session->host ? session->host : session->ip); |
202 |
stdarg |
1.1 |
session->state = STATE_PARTYLINE; |
203 |
stdarg |
1.2 |
egg_iprintf(idx, "\r\nWelcome to the telnet partyline interface!\r\n"); |
204 |
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if (session->ident) egg_iprintf(idx, "Your ident is: %s\r\n", session->ident); |
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if (session->host) egg_iprintf(idx, "Your hostname is: %s\r\n", session->host); |
206 |
stdarg |
1.1 |
} |
207 |
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break; |
208 |
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} |
209 |
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return(0); |
210 |
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} |
211 |
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212 |
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static int telnet_on_eof(void *client_data, int idx, int err, const char *errmsg) |
213 |
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{ |
214 |
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telnet_session_t *session = client_data; |
215 |
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216 |
stdarg |
1.2 |
if (session->state == STATE_PARTYLINE) partyline_disconnect(session->pid, err ? errmsg : NULL); |
217 |
stdarg |
1.1 |
kill_session(session); |
218 |
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return(0); |
219 |
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} |
220 |
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221 |
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static int telnet_filter_read(void *client_data, int idx, char *data, int len) |
222 |
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{ |
223 |
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char *cmd; |
224 |
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int type, arg, remove, flags; |
225 |
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226 |
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flags = *(int *)client_data; |
227 |
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cmd = data; |
228 |
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while ((cmd = memchr(cmd, TELNET_CMD, len))) { |
229 |
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type = *(unsigned char *)(cmd+1); |
230 |
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if (type == TELNET_CMD) remove = 1; |
231 |
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else if (type == TELNET_DO) { |
232 |
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arg = *(cmd+2); |
233 |
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if (arg == TELNET_ECHO) flags |= TFLAG_ECHO; |
234 |
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remove = 3; |
235 |
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} |
236 |
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else if (type == TELNET_DONT) { |
237 |
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arg = *(cmd+2); |
238 |
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if (arg == TELNET_ECHO) flags &= ~TFLAG_ECHO; |
239 |
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remove = 3; |
240 |
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} |
241 |
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else if (type == TELNET_WILL || type == TELNET_WONT) { |
242 |
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remove = 3; |
243 |
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} |
244 |
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else { |
245 |
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remove = 2; |
246 |
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} |
247 |
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memmove(cmd, cmd+remove, len - (cmd - data) - remove + 1); |
248 |
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len -= remove; |
249 |
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} |
250 |
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if (len) { |
251 |
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if (flags & TFLAG_ECHO) sockbuf_on_write(idx, TELNET_FILTER_LEVEL, data, len); |
252 |
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sockbuf_on_read(idx, TELNET_FILTER_LEVEL, data, len); |
253 |
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} |
254 |
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return(0); |
255 |
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} |
256 |
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257 |
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/* We replace \n with \r\n and \255 with \255\255. */ |
258 |
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static int telnet_filter_write(void *client_data, int idx, const char *data, int len) |
259 |
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{ |
260 |
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const char *newline; |
261 |
stdarg |
1.2 |
int left, linelen, r, r2; |
262 |
stdarg |
1.1 |
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263 |
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newline = data; |
264 |
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r = 0; |
265 |
stdarg |
1.2 |
left = len; |
266 |
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while ((newline = memchr(newline, '\n', left))) { |
267 |
stdarg |
1.1 |
linelen = newline - data; |
268 |
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if (linelen > 0 && newline[-1] == '\r') { |
269 |
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newline++; |
270 |
stdarg |
1.2 |
left = len - linelen - 1; |
271 |
stdarg |
1.1 |
continue; |
272 |
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} |
273 |
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274 |
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r2 = sockbuf_on_write(idx, TELNET_FILTER_LEVEL, data, linelen); |
275 |
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if (r2 < 0) return(r2); |
276 |
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r += r2; |
277 |
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r2 = sockbuf_on_write(idx, TELNET_FILTER_LEVEL, "\r\n", 2); |
278 |
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if (r2 < 0) return(r2); |
279 |
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r += r2; |
280 |
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data = newline+1; |
281 |
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newline = data; |
282 |
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len -= linelen+1; |
283 |
stdarg |
1.2 |
left = len; |
284 |
stdarg |
1.1 |
} |
285 |
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if (len > 0) { |
286 |
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r2 = sockbuf_on_write(idx, TELNET_FILTER_LEVEL, data, len); |
287 |
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if (r2 < 0) return(r2); |
288 |
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r += r2; |
289 |
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} |
290 |
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return(r); |
291 |
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} |
292 |
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293 |
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static int telnet_filter_delete(void *client_data, int idx) |
294 |
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{ |
295 |
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free(client_data); |
296 |
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return(0); |
297 |
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} |