| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * $Id: identify.c,v 1.1 1999/07/01 08:56:23 mdw Exp $ |
| 4 | * |
| 5 | * Identifies and logs the client of a connection |
| 6 | * |
| 7 | * (c) 1999 Mark Wooding |
| 8 | */ |
| 9 | |
| 10 | /*----- Licensing notice --------------------------------------------------* |
| 11 | * |
| 12 | * This file is part of the `fw' port forwarder. |
| 13 | * |
| 14 | * `fw' is free software; you can redistribute it and/or modify |
| 15 | * it under the terms of the GNU General Public License as published by |
| 16 | * the Free Software Foundation; either version 2 of the License, or |
| 17 | * (at your option) any later version. |
| 18 | * |
| 19 | * `fw' is distributed in the hope that it will be useful, |
| 20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 22 | * GNU General Public License for more details. |
| 23 | * |
| 24 | * You should have received a copy of the GNU General Public License |
| 25 | * along with `fw'; if not, write to the Free Software Foundation, |
| 26 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 27 | */ |
| 28 | |
| 29 | /*----- Revision history --------------------------------------------------* |
| 30 | * |
| 31 | * $Log: identify.c,v $ |
| 32 | * Revision 1.1 1999/07/01 08:56:23 mdw |
| 33 | * Initial revision |
| 34 | * |
| 35 | */ |
| 36 | |
| 37 | /*----- Header files ------------------------------------------------------*/ |
| 38 | |
| 39 | #include "config.h" |
| 40 | |
| 41 | #include <errno.h> |
| 42 | #include <stdio.h> |
| 43 | #include <stdlib.h> |
| 44 | #include <string.h> |
| 45 | #include <time.h> |
| 46 | |
| 47 | #include <sys/types.h> |
| 48 | #include <sys/time.h> |
| 49 | #include <unistd.h> |
| 50 | #include <syslog.h> |
| 51 | |
| 52 | #include <sys/socket.h> |
| 53 | #include <netinet/in.h> |
| 54 | #include <arpa/inet.h> |
| 55 | #include <netdb.h> |
| 56 | |
| 57 | #include <mLib/alloc.h> |
| 58 | #include <mLib/conn.h> |
| 59 | #include <mLib/dstr.h> |
| 60 | #include <mLib/report.h> |
| 61 | #include <mLib/sel.h> |
| 62 | #include <mLib/selbuf.h> |
| 63 | #include <mLib/str.h> |
| 64 | |
| 65 | #include "bres.h" |
| 66 | #include "fw.h" |
| 67 | #include "ident.h" |
| 68 | #include "identify.h" |
| 69 | |
| 70 | /*----- Magic numbers -----------------------------------------------------*/ |
| 71 | |
| 72 | #define TIMEOUT 15 /* Seconds to wait for answers */ |
| 73 | |
| 74 | /*----- Data structures ---------------------------------------------------*/ |
| 75 | |
| 76 | /* --- Structure to track the progress of an identification --- */ |
| 77 | |
| 78 | typedef struct id { |
| 79 | id_req q; /* Copy of client's request block */ |
| 80 | void (*func)(void */*p*/); /* Function to call when done */ |
| 81 | void *p; /* Argument to pass to function */ |
| 82 | time_t when; /* When the connection occurred */ |
| 83 | conn c; /* Connection selector */ |
| 84 | unsigned state; /* Current state of the world */ |
| 85 | bres_client r; /* Backgd resolver client block */ |
| 86 | char host[64]; /* Resolved hostname */ |
| 87 | char user[32]; /* Authenticated client user */ |
| 88 | sel_timer t; /* Timeout selector */ |
| 89 | selbuf id; /* Reader for the RFC931 client */ |
| 90 | } id; |
| 91 | |
| 92 | #define S_HOST 1u /* Read the hostname from resolver */ |
| 93 | #define S_USER 2u /* Read the username from RFC931 */ |
| 94 | #define S_UCONN 4u /* Connected to remote RFC931 */ |
| 95 | #define S_TIMER 8u /* Timeout has completed */ |
| 96 | |
| 97 | /*----- Main code ---------------------------------------------------------*/ |
| 98 | |
| 99 | /* --- @id_done@ --- * |
| 100 | * |
| 101 | * Arguments: @id *i@ = pointer to identification block |
| 102 | * |
| 103 | * Returns: --- |
| 104 | * |
| 105 | * Use: Finishes with an identification block. |
| 106 | */ |
| 107 | |
| 108 | static void id_done(id *i) |
| 109 | { |
| 110 | char buf[64]; |
| 111 | struct tm *tm; |
| 112 | |
| 113 | /* --- Close down the various dependent bits --- */ |
| 114 | |
| 115 | if (!(i->state & S_HOST)) |
| 116 | bres_abort(&i->r); |
| 117 | if (!(i->state & S_UCONN)) |
| 118 | conn_kill(&i->c); |
| 119 | else if (!(i->state & S_USER)) |
| 120 | selbuf_disable(&i->id); |
| 121 | if (!(i->state & S_TIMER)) |
| 122 | sel_rmtimer(&i->t); |
| 123 | |
| 124 | /* --- Report the final result --- */ |
| 125 | |
| 126 | tm = localtime(&i->when); |
| 127 | strftime(buf, sizeof(buf), "%Y-%m-%d %H:%M:%S", tm); |
| 128 | syslog(LOG_NOTICE, "%s %s %s from %s@%s\n", |
| 129 | buf, i->q.desc, i->q.act, i->user, i->host); |
| 130 | |
| 131 | /* --- Dispose of the block --- */ |
| 132 | |
| 133 | i->func(i->p); |
| 134 | free(i); |
| 135 | } |
| 136 | |
| 137 | /* --- @id_res@ --- * |
| 138 | * |
| 139 | * Arguments: @const char *host@ = name of the resolved host |
| 140 | * @void *vp@ = pointer to identification block |
| 141 | * |
| 142 | * Returns: --- |
| 143 | * |
| 144 | * Use: Responds to a completed reverse name resolution. |
| 145 | */ |
| 146 | |
| 147 | static void id_res(const char *host, void *vp) |
| 148 | { |
| 149 | id *i = vp; |
| 150 | str_sanitize(i->host, host, sizeof(i->host)); |
| 151 | i->state |= S_HOST; |
| 152 | if (i->state & S_USER) |
| 153 | id_done(i); |
| 154 | } |
| 155 | |
| 156 | /* --- @id_ident@ --- * |
| 157 | * |
| 158 | * Arguments: @char *p@ = pointer to string read from server |
| 159 | * @void *vp@ = pointer to identification block |
| 160 | * |
| 161 | * Returns: --- |
| 162 | * |
| 163 | * Use: Responds to a line read from the remote RFC931 server. |
| 164 | */ |
| 165 | |
| 166 | static void id_ident(char *p, void *vp) |
| 167 | { |
| 168 | id *i = vp; |
| 169 | |
| 170 | /* --- Get rid of the connection --- */ |
| 171 | |
| 172 | i->state |= S_USER; |
| 173 | selbuf_disable(&i->id); |
| 174 | close(i->id.reader.fd); |
| 175 | |
| 176 | /* --- Read the information from the returned line --- */ |
| 177 | |
| 178 | if (p) { |
| 179 | ident idbuf; |
| 180 | ident_parse(p, &idbuf); |
| 181 | if (idbuf.type == ident_userid) |
| 182 | str_sanitize(i->user, idbuf.u.userid.user, sizeof(i->user)); |
| 183 | } |
| 184 | |
| 185 | /* --- Maybe finish off this identification --- */ |
| 186 | |
| 187 | if (i->state & S_HOST) |
| 188 | id_done(i); |
| 189 | } |
| 190 | |
| 191 | /* --- @id_conn@ --- * |
| 192 | * |
| 193 | * Arguments: @int fd@ = file descriptor connected |
| 194 | * @void *vp@ = pointer to identification block |
| 195 | * |
| 196 | * Returns: --- |
| 197 | * |
| 198 | * Use: Responds to a completed connection to the remote RFC931 |
| 199 | * server. |
| 200 | */ |
| 201 | |
| 202 | static void id_conn(int fd, void *vp) |
| 203 | { |
| 204 | id *i = vp; |
| 205 | |
| 206 | if (fd == -1) { |
| 207 | i->state |= S_USER | S_UCONN; |
| 208 | if (i->state & S_HOST) |
| 209 | id_done(i); |
| 210 | } else { |
| 211 | dstr d = DSTR_INIT; |
| 212 | dstr_putf(&d, "%u, %u\n", |
| 213 | ntohs(i->q.rsin.sin_port), ntohs(i->q.lsin.sin_port)); |
| 214 | write(fd, d.buf, d.len); |
| 215 | dstr_destroy(&d); |
| 216 | i->state |= S_UCONN; |
| 217 | selbuf_init(&i->id, sel, fd, id_ident, i); |
| 218 | } |
| 219 | } |
| 220 | |
| 221 | /* --- @id_timer@ --- * |
| 222 | * |
| 223 | * Arguments: @struct timeval *tv@ = pointer to the current time |
| 224 | * @void *vp@ = pointer to identification block |
| 225 | * |
| 226 | * Returns: --- |
| 227 | * |
| 228 | * Use: Times an identification job out. |
| 229 | */ |
| 230 | |
| 231 | static void id_timer(struct timeval *tv, void *vp) |
| 232 | { |
| 233 | id *i = vp; |
| 234 | id_done(i); |
| 235 | } |
| 236 | |
| 237 | /* --- @identify@ --- * |
| 238 | * |
| 239 | * Arguments: @const id_req *q@ = pointer to request block |
| 240 | * @void (*func)(void *p)@ = function to call when done |
| 241 | * @void *p@ = argument to pass to function |
| 242 | * |
| 243 | * Returns: --- |
| 244 | * |
| 245 | * Use: Starts a background ident lookup and reverse-resolve job |
| 246 | * which will, eventually, report a message to the system log. |
| 247 | */ |
| 248 | |
| 249 | void identify(const id_req *q, |
| 250 | void (*func)(void */*p*/), void *p) |
| 251 | { |
| 252 | id *i; |
| 253 | |
| 254 | /* --- Initialize the block with stuff --- */ |
| 255 | |
| 256 | i = xmalloc(sizeof(*i)); |
| 257 | i->q = *q; |
| 258 | i->func = func; |
| 259 | i->p = p; |
| 260 | |
| 261 | str_sanitize(i->host, inet_ntoa(q->rsin.sin_addr), sizeof(i->host)); |
| 262 | strcpy(i->user, "<ANONYMOUS>"); |
| 263 | i->state = 0; |
| 264 | i->when = time(0); |
| 265 | |
| 266 | /* --- Set up the connection to the identity server --- */ |
| 267 | |
| 268 | { |
| 269 | int fd; |
| 270 | struct sockaddr_in sin; |
| 271 | |
| 272 | if ((fd = socket(PF_INET, SOCK_STREAM, 0)) < 0) |
| 273 | id_conn(-1, i); |
| 274 | else { |
| 275 | sin.sin_family = AF_INET; |
| 276 | sin.sin_addr = q->lsin.sin_addr; |
| 277 | sin.sin_port = 0; |
| 278 | if (bind(fd, (struct sockaddr *)&sin, sizeof(sin))) { |
| 279 | close(fd); |
| 280 | id_conn(-1, i); |
| 281 | } else { |
| 282 | sin.sin_family = AF_INET; |
| 283 | sin.sin_addr = q->rsin.sin_addr; |
| 284 | sin.sin_port = htons(113); |
| 285 | conn_init(&i->c, sel, fd, |
| 286 | (struct sockaddr *)&sin, sizeof(sin), |
| 287 | id_conn, i); |
| 288 | } |
| 289 | } |
| 290 | } |
| 291 | |
| 292 | /* --- Set up the name resolver --- */ |
| 293 | |
| 294 | bres_resolve(&i->r, q->rsin.sin_addr, id_res, i); |
| 295 | |
| 296 | /* --- Set up the time limiter --- */ |
| 297 | |
| 298 | { |
| 299 | struct timeval tv; |
| 300 | gettimeofday(&tv, 0); |
| 301 | tv.tv_sec += TIMEOUT; |
| 302 | sel_addtimer(sel, &i->t, &tv, id_timer, i); |
| 303 | } |
| 304 | } |
| 305 | |
| 306 | /*----- That's all, folks -------------------------------------------------*/ |