1 /* $NetBSD: security.c,v 1.5 2000/06/08 09:01:05 fvdl Exp $ */ 2 /* $FreeBSD$ */ 3 4 #include <sys/types.h> 5 #include <sys/time.h> 6 #include <sys/socket.h> 7 #include <netinet/in.h> 8 #include <arpa/inet.h> 9 #include <rpc/rpc.h> 10 #include <rpc/rpcb_prot.h> 11 #include <rpc/pmap_prot.h> 12 #include <err.h> 13 #include <stdio.h> 14 #include <stdlib.h> 15 #include <string.h> 16 #include <unistd.h> 17 #include <libutil.h> 18 #include <syslog.h> 19 #include <netdb.h> 20 21 /* 22 * XXX for special case checks in check_callit. 23 */ 24 #include <rpcsvc/mount.h> 25 #include <rpcsvc/rquota.h> 26 #include <rpcsvc/nfs_prot.h> 27 #include <rpcsvc/yp.h> 28 #include <rpcsvc/ypclnt.h> 29 #include <rpcsvc/yppasswd.h> 30 31 #include "rpcbind.h" 32 33 #ifdef LIBWRAP 34 # include <tcpd.h> 35 #ifndef LIBWRAP_ALLOW_FACILITY 36 # define LIBWRAP_ALLOW_FACILITY LOG_AUTH 37 #endif 38 #ifndef LIBWRAP_ALLOW_SEVERITY 39 # define LIBWRAP_ALLOW_SEVERITY LOG_INFO 40 #endif 41 #ifndef LIBWRAP_DENY_FACILITY 42 # define LIBWRAP_DENY_FACILITY LOG_AUTH 43 #endif 44 #ifndef LIBWRAP_DENY_SEVERITY 45 # define LIBWRAP_DENY_SEVERITY LOG_WARNING 46 #endif 47 int allow_severity = LIBWRAP_ALLOW_FACILITY|LIBWRAP_ALLOW_SEVERITY; 48 int deny_severity = LIBWRAP_DENY_FACILITY|LIBWRAP_DENY_SEVERITY; 49 #endif 50 51 #ifndef PORTMAP_LOG_FACILITY 52 # define PORTMAP_LOG_FACILITY LOG_AUTH 53 #endif 54 #ifndef PORTMAP_LOG_SEVERITY 55 # define PORTMAP_LOG_SEVERITY LOG_INFO 56 #endif 57 int log_severity = PORTMAP_LOG_FACILITY|PORTMAP_LOG_SEVERITY; 58 59 extern int verboselog; 60 61 int 62 check_access(SVCXPRT *xprt, rpcproc_t proc, void *args, unsigned int rpcbvers) 63 { 64 struct netbuf *caller = svc_getrpccaller(xprt); 65 struct sockaddr *addr = (struct sockaddr *)caller->buf; 66 #ifdef LIBWRAP 67 struct request_info req; 68 #endif 69 rpcprog_t prog = 0; 70 rpcb *rpcbp; 71 struct pmap *pmap; 72 73 /* 74 * The older PMAP_* equivalents have the same numbers, so 75 * they are accounted for here as well. 76 */ 77 switch (proc) { 78 case RPCBPROC_GETADDR: 79 case RPCBPROC_SET: 80 case RPCBPROC_UNSET: 81 if (rpcbvers > PMAPVERS) { 82 rpcbp = (rpcb *)args; 83 prog = rpcbp->r_prog; 84 } else { 85 pmap = (struct pmap *)args; 86 prog = pmap->pm_prog; 87 } 88 if (proc == RPCBPROC_GETADDR) 89 break; 90 if (!insecure && !is_loopback(caller)) { 91 if (verboselog) 92 logit(log_severity, addr, proc, prog, 93 " declined (non-loopback sender)"); 94 return 0; 95 } 96 break; 97 case RPCBPROC_CALLIT: 98 case RPCBPROC_INDIRECT: 99 case RPCBPROC_DUMP: 100 case RPCBPROC_GETTIME: 101 case RPCBPROC_UADDR2TADDR: 102 case RPCBPROC_TADDR2UADDR: 103 case RPCBPROC_GETVERSADDR: 104 case RPCBPROC_GETADDRLIST: 105 case RPCBPROC_GETSTAT: 106 default: 107 break; 108 } 109 110 #ifdef LIBWRAP 111 if (libwrap && addr->sa_family != AF_LOCAL) { 112 request_init(&req, RQ_DAEMON, "rpcbind", RQ_CLIENT_SIN, addr, 113 0); 114 sock_methods(&req); 115 if(!hosts_access(&req)) { 116 logit(deny_severity, addr, proc, prog, 117 ": request from unauthorized host"); 118 return 0; 119 } 120 } 121 #endif 122 if (verboselog) 123 logit(log_severity, addr, proc, prog, ""); 124 return 1; 125 } 126 127 int 128 is_loopback(struct netbuf *nbuf) 129 { 130 struct sockaddr *addr = (struct sockaddr *)nbuf->buf; 131 struct sockaddr_in *sin; 132 #ifdef INET6 133 struct sockaddr_in6 *sin6; 134 #endif 135 136 switch (addr->sa_family) { 137 case AF_INET: 138 if (!oldstyle_local) 139 return 0; 140 sin = (struct sockaddr_in *)addr; 141 return ((sin->sin_addr.s_addr == htonl(INADDR_LOOPBACK)) && 142 (ntohs(sin->sin_port) < IPPORT_RESERVED)); 143 #ifdef INET6 144 case AF_INET6: 145 if (!oldstyle_local) 146 return 0; 147 sin6 = (struct sockaddr_in6 *)addr; 148 return (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr) && 149 (ntohs(sin6->sin6_port) < IPV6PORT_RESERVED)); 150 #endif 151 case AF_LOCAL: 152 return 1; 153 default: 154 break; 155 } 156 157 return 0; 158 } 159 160 161 /* logit - report events of interest via the syslog daemon */ 162 void 163 logit(int severity, struct sockaddr *addr, rpcproc_t procnum, rpcprog_t prognum, 164 const char *text) 165 { 166 const char *procname; 167 char procbuf[32]; 168 char *progname; 169 char progbuf[32]; 170 char fromname[NI_MAXHOST]; 171 struct rpcent *rpc; 172 static const char *procmap[] = { 173 /* RPCBPROC_NULL */ "null", 174 /* RPCBPROC_SET */ "set", 175 /* RPCBPROC_UNSET */ "unset", 176 /* RPCBPROC_GETADDR */ "getport/addr", 177 /* RPCBPROC_DUMP */ "dump", 178 /* RPCBPROC_CALLIT */ "callit", 179 /* RPCBPROC_GETTIME */ "gettime", 180 /* RPCBPROC_UADDR2TADDR */ "uaddr2taddr", 181 /* RPCBPROC_TADDR2UADDR */ "taddr2uaddr", 182 /* RPCBPROC_GETVERSADDR */ "getversaddr", 183 /* RPCBPROC_INDIRECT */ "indirect", 184 /* RPCBPROC_GETADDRLIST */ "getaddrlist", 185 /* RPCBPROC_GETSTAT */ "getstat" 186 }; 187 188 /* 189 * Fork off a process or the portmap daemon might hang while 190 * getrpcbynumber() or syslog() does its thing. 191 */ 192 193 if (fork() == 0) { 194 setproctitle("logit"); 195 196 /* Try to map program number to name. */ 197 198 if (prognum == 0) { 199 progname = ""; 200 } else if ((rpc = getrpcbynumber((int) prognum))) { 201 progname = rpc->r_name; 202 } else { 203 snprintf(progname = progbuf, sizeof(progbuf), "%u", 204 (unsigned)prognum); 205 } 206 207 /* Try to map procedure number to name. */ 208 209 if (procnum >= (sizeof procmap / sizeof (char *))) { 210 snprintf(procbuf, sizeof procbuf, "%u", 211 (unsigned)procnum); 212 procname = procbuf; 213 } else 214 procname = procmap[procnum]; 215 216 /* Write syslog record. */ 217 218 if (addr->sa_family == AF_LOCAL) 219 strcpy(fromname, "local"); 220 else 221 getnameinfo(addr, addr->sa_len, fromname, 222 sizeof fromname, NULL, 0, NI_NUMERICHOST); 223 224 syslog(severity, "connect from %s to %s(%s)%s", 225 fromname, procname, progname, text); 226 _exit(0); 227 } 228 } 229 230 int 231 check_callit(SVCXPRT *xprt, struct r_rmtcall_args *args, int versnum __unused) 232 { 233 struct sockaddr *sa = (struct sockaddr *)svc_getrpccaller(xprt)->buf; 234 235 /* 236 * Always allow calling NULLPROC 237 */ 238 if (args->rmt_proc == 0) 239 return 1; 240 241 /* 242 * XXX - this special casing sucks. 243 */ 244 switch (args->rmt_prog) { 245 case RPCBPROG: 246 /* 247 * Allow indirect calls to ourselves in insecure mode. 248 * The is_loopback checks aren't useful then anyway. 249 */ 250 if (!insecure) 251 goto deny; 252 break; 253 case MOUNTPROG: 254 if (args->rmt_proc != MOUNTPROC_MNT && 255 args->rmt_proc != MOUNTPROC_UMNT) 256 break; 257 goto deny; 258 case YPBINDPROG: 259 if (args->rmt_proc != YPBINDPROC_SETDOM) 260 break; 261 /* FALLTHROUGH */ 262 case YPPASSWDPROG: 263 case NFS_PROGRAM: 264 case RQUOTAPROG: 265 goto deny; 266 case YPPROG: 267 switch (args->rmt_proc) { 268 case YPPROC_ALL: 269 case YPPROC_MATCH: 270 case YPPROC_FIRST: 271 case YPPROC_NEXT: 272 goto deny; 273 default: 274 break; 275 } 276 default: 277 break; 278 } 279 280 return 1; 281 deny: 282 #ifdef LIBWRAP 283 logit(deny_severity, sa, args->rmt_proc, args->rmt_prog, 284 ": indirect call not allowed"); 285 #else 286 logit(0, sa, args->rmt_proc, args->rmt_prog, 287 ": indirect call not allowed"); 288 #endif 289 return 0; 290 } 291