1 /* $FreeBSD$ */ 2 /* 3 * Routines to parse an inetd.conf or tlid.conf file. This would be a great 4 * job for a PERL script. 5 * 6 * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands. 7 */ 8 9 #ifndef lint 10 static char sccsid[] = "@(#) inetcf.c 1.7 97/02/12 02:13:23"; 11 #endif 12 13 #include <sys/types.h> 14 #include <sys/stat.h> 15 #include <stdio.h> 16 #include <errno.h> 17 #include <stdlib.h> 18 #include <string.h> 19 20 #include "tcpd.h" 21 #include "inetcf.h" 22 #include "scaffold.h" 23 24 /* 25 * Network configuration files may live in unusual places. Here are some 26 * guesses. Shorter names follow longer ones. 27 */ 28 char *inet_files[] = { 29 "/private/etc/inetd.conf", /* NEXT */ 30 "/etc/inet/inetd.conf", /* SYSV4 */ 31 "/usr/etc/inetd.conf", /* IRIX?? */ 32 "/etc/inetd.conf", /* BSD */ 33 "/etc/net/tlid.conf", /* SYSV4?? */ 34 "/etc/saf/tlid.conf", /* SYSV4?? */ 35 "/etc/tlid.conf", /* SYSV4?? */ 36 0, 37 }; 38 39 static void inet_chk(char *protocol, char *path, char *arg0, char *arg1); 40 static char *base_name(char *path); 41 extern char *percent_m(char *obuf, char *ibuf); 42 43 /* 44 * Structure with everything we know about a service. 45 */ 46 struct inet_ent { 47 struct inet_ent *next; 48 int type; 49 char name[1]; 50 }; 51 52 static struct inet_ent *inet_list = 0; 53 54 static char whitespace[] = " \t\r\n"; 55 56 /* inet_conf - read in and examine inetd.conf (or tlid.conf) entries */ 57 58 char *inet_cfg(char *conf) 59 { 60 char buf[BUFSIZ]; 61 FILE *fp; 62 char *service; 63 char *protocol; 64 char *user; 65 char *path; 66 char *arg0; 67 char *arg1; 68 struct tcpd_context saved_context; 69 int i; 70 struct stat st; 71 72 saved_context = tcpd_context; 73 74 /* 75 * The inetd.conf (or tlid.conf) information is so useful that we insist 76 * on its availability. When no file is given run a series of educated 77 * guesses. 78 */ 79 if (conf != 0) { 80 if ((fp = fopen(conf, "r")) == 0) { 81 fprintf(stderr, percent_m(buf, "open %s: %m\n"), conf); 82 exit(1); 83 } 84 } else { 85 for (i = 0; inet_files[i] && (fp = fopen(inet_files[i], "r")) == 0; i++) 86 /* void */ ; 87 if (fp == 0) { 88 fprintf(stderr, "Cannot find your inetd.conf or tlid.conf file.\n"); 89 fprintf(stderr, "Please specify its location.\n"); 90 exit(1); 91 } 92 conf = inet_files[i]; 93 check_path(conf, &st); 94 } 95 96 /* 97 * Process the file. After the 7.0 wrapper release it became clear that 98 * there are many more inetd.conf formats than the 8 systems that I had 99 * studied. EP/IX uses a two-line specification for rpc services; HP-UX 100 * permits long lines to be broken with backslash-newline. 101 */ 102 tcpd_context.file = conf; 103 tcpd_context.line = 0; 104 while (xgets(buf, sizeof(buf), fp)) { 105 service = strtok(buf, whitespace); /* service */ 106 if (service == 0 || *service == '#') 107 continue; 108 if (STR_NE(service, "stream") && STR_NE(service, "dgram")) 109 strtok((char *) 0, whitespace); /* endpoint */ 110 protocol = strtok((char *) 0, whitespace); 111 (void) strtok((char *) 0, whitespace); /* wait */ 112 if ((user = strtok((char *) 0, whitespace)) == 0) 113 continue; 114 if (user[0] == '/') { /* user */ 115 path = user; 116 } else { /* path */ 117 if ((path = strtok((char *) 0, whitespace)) == 0) 118 continue; 119 } 120 if (path[0] == '?') /* IRIX optional service */ 121 path++; 122 if (STR_EQ(path, "internal")) 123 continue; 124 if (path[strspn(path, "-0123456789")] == 0) { 125 126 /* 127 * ConvexOS puts RPC version numbers before path names. Jukka 128 * Ukkonen <ukkonen@csc.fi>. 129 */ 130 if ((path = strtok((char *) 0, whitespace)) == 0) 131 continue; 132 } 133 if ((arg0 = strtok((char *) 0, whitespace)) == 0) { 134 tcpd_warn("incomplete line"); 135 continue; 136 } 137 if (arg0[strspn(arg0, "0123456789")] == 0) { 138 139 /* 140 * We're reading a tlid.conf file, the format is: 141 * 142 * ...stuff... path arg_count arguments mod_count modules 143 */ 144 if ((arg0 = strtok((char *) 0, whitespace)) == 0) { 145 tcpd_warn("incomplete line"); 146 continue; 147 } 148 } 149 if ((arg1 = strtok((char *) 0, whitespace)) == 0) 150 arg1 = ""; 151 152 inet_chk(protocol, path, arg0, arg1); 153 } 154 fclose(fp); 155 tcpd_context = saved_context; 156 return (conf); 157 } 158 159 /* inet_chk - examine one inetd.conf (tlid.conf?) entry */ 160 161 static void inet_chk(char *protocol, char *path, char *arg0, char *arg1) 162 { 163 char daemon[BUFSIZ]; 164 struct stat st; 165 int wrap_status = WR_MAYBE; 166 char *base_name_path = base_name(path); 167 char *tcpd_proc_name = (arg0[0] == '/' ? base_name(arg0) : arg0); 168 169 /* 170 * Always warn when the executable does not exist or when it is not 171 * executable. 172 */ 173 if (check_path(path, &st) < 0) { 174 tcpd_warn("%s: not found: %m", path); 175 } else if ((st.st_mode & 0100) == 0) { 176 tcpd_warn("%s: not executable", path); 177 } 178 179 /* 180 * Cheat on the miscd tests, nobody uses it anymore. 181 */ 182 if (STR_EQ(base_name_path, "miscd")) { 183 inet_set(arg0, WR_YES); 184 return; 185 } 186 187 /* 188 * While we are here... 189 */ 190 if (STR_EQ(tcpd_proc_name, "rexd") || STR_EQ(tcpd_proc_name, "rpc.rexd")) 191 tcpd_warn("%s may be an insecure service", tcpd_proc_name); 192 193 /* 194 * The tcpd program gets most of the attention. 195 */ 196 if (STR_EQ(base_name_path, "tcpd")) { 197 198 if (STR_EQ(tcpd_proc_name, "tcpd")) 199 tcpd_warn("%s is recursively calling itself", tcpd_proc_name); 200 201 wrap_status = WR_YES; 202 203 /* 204 * Check: some sites install the wrapper set-uid. 205 */ 206 if ((st.st_mode & 06000) != 0) 207 tcpd_warn("%s: file is set-uid or set-gid", path); 208 209 /* 210 * Check: some sites insert tcpd in inetd.conf, instead of replacing 211 * the daemon pathname. 212 */ 213 if (arg0[0] == '/' && STR_EQ(tcpd_proc_name, base_name(arg1))) 214 tcpd_warn("%s inserted before %s", path, arg0); 215 216 /* 217 * Check: make sure files exist and are executable. On some systems 218 * the network daemons are set-uid so we cannot complain. Note that 219 * tcpd takes the basename only in case of absolute pathnames. 220 */ 221 if (arg0[0] == '/') { /* absolute path */ 222 if (check_path(arg0, &st) < 0) { 223 tcpd_warn("%s: not found: %m", arg0); 224 } else if ((st.st_mode & 0100) == 0) { 225 tcpd_warn("%s: not executable", arg0); 226 } 227 } else { /* look in REAL_DAEMON_DIR */ 228 sprintf(daemon, "%s/%s", REAL_DAEMON_DIR, arg0); 229 if (check_path(daemon, &st) < 0) { 230 tcpd_warn("%s: not found in %s: %m", 231 arg0, REAL_DAEMON_DIR); 232 } else if ((st.st_mode & 0100) == 0) { 233 tcpd_warn("%s: not executable", daemon); 234 } 235 } 236 237 } else { 238 239 /* 240 * No tcpd program found. Perhaps they used the "simple installation" 241 * recipe. Look for a file with the same basename in REAL_DAEMON_DIR. 242 * Draw some conservative conclusions when a distinct file is found. 243 */ 244 sprintf(daemon, "%s/%s", REAL_DAEMON_DIR, arg0); 245 if (STR_EQ(path, daemon)) { 246 #ifdef __FreeBSD__ 247 wrap_status = WR_MAYBE; 248 #else 249 wrap_status = WR_NOT; 250 #endif 251 } else if (check_path(daemon, &st) >= 0) { 252 wrap_status = WR_MAYBE; 253 } else if (errno == ENOENT) { 254 wrap_status = WR_NOT; 255 } else { 256 tcpd_warn("%s: file lookup: %m", daemon); 257 wrap_status = WR_MAYBE; 258 } 259 } 260 261 /* 262 * Alas, we cannot wrap rpc/tcp services. 263 */ 264 if (wrap_status == WR_YES && STR_EQ(protocol, "rpc/tcp")) 265 tcpd_warn("%s: cannot wrap rpc/tcp services", tcpd_proc_name); 266 267 inet_set(tcpd_proc_name, wrap_status); 268 } 269 270 /* inet_set - remember service status */ 271 272 void inet_set(char *name, int type) 273 { 274 struct inet_ent *ip = 275 (struct inet_ent *) malloc(sizeof(struct inet_ent) + strlen(name)); 276 277 if (ip == 0) { 278 fprintf(stderr, "out of memory\n"); 279 exit(1); 280 } 281 ip->next = inet_list; 282 strcpy(ip->name, name); 283 ip->type = type; 284 inet_list = ip; 285 } 286 287 /* inet_get - look up service status */ 288 289 int inet_get(char *name) 290 { 291 struct inet_ent *ip; 292 293 if (inet_list == 0) 294 return (WR_MAYBE); 295 296 for (ip = inet_list; ip; ip = ip->next) 297 if (STR_EQ(ip->name, name)) 298 return (ip->type); 299 300 return (-1); 301 } 302 303 /* base_name - compute last pathname component */ 304 305 static char *base_name(char *path) 306 { 307 char *cp; 308 309 if ((cp = strrchr(path, '/')) != 0) 310 path = cp + 1; 311 return (path); 312 } 313