| 1 | /**/ |
| 2 | |
| 3 | #include <stdarg.h> |
| 4 | #include <stdio.h> |
| 5 | #include <errno.h> |
| 6 | #include <string.h> |
| 7 | #include <stdlib.h> |
| 8 | #include <assert.h> |
| 9 | #include <unistd.h> |
| 10 | |
| 11 | #include <netdb.h> |
| 12 | #include <arpa/nameser.h> |
| 13 | #include <sys/socket.h> |
| 14 | #include <netinet/in.h> |
| 15 | #include <arpa/inet.h> |
| 16 | |
| 17 | #include "adns-internal.h" |
| 18 | |
| 19 | #define LIST_UNLINK_PART(list,node,part) \ |
| 20 | do { \ |
| 21 | if ((node)->back) (node)->back->part next= (node)->part next; \ |
| 22 | else (list).head= (node)->part next; \ |
| 23 | if ((node)->next) (node)->next->part back= (node)->part back; \ |
| 24 | else (list).tail= (node)->part back; \ |
| 25 | } while(0) |
| 26 | |
| 27 | #define LIST_LINK_TAIL_PART(list,node,part) \ |
| 28 | do { \ |
| 29 | (node)->part back= 0; \ |
| 30 | (node)->part next= (list).tail; \ |
| 31 | if ((list).tail) (list).tail->part back= (node); else (list).part head= (node); \ |
| 32 | (list).tail= (node); \ |
| 33 | } while(0) |
| 34 | |
| 35 | #define LIST_UNLINK(list,node) LIST_UNLINK_PART(list,node,) |
| 36 | #define LIST_LINK_TAIL_PART(list,node) LIST_LINK_TAIL(list,node,) |
| 37 | |
| 38 | static void vdebug(adns_state ads, const char *fmt, va_list al) { |
| 39 | if (!(ads->iflags & adns_if_debug)) return; |
| 40 | fputs("adns debug: ",stderr); |
| 41 | vfprintf(stderr,fmt,al); |
| 42 | fputc('\n',stderr); |
| 43 | } |
| 44 | |
| 45 | static void debug(adns_state ads, const char *fmt, ...) { |
| 46 | va_list al; |
| 47 | |
| 48 | va_start(al,fmt); |
| 49 | vdebug(ads,fmt,al); |
| 50 | va_end(al); |
| 51 | } |
| 52 | |
| 53 | static void vdiag(adns_state ads, const char *fmt, va_list al) { |
| 54 | if (ads->iflags & adns_if_noerrprint) return; |
| 55 | fputs("adns: ",stderr); |
| 56 | vfprintf(stderr,fmt,al); |
| 57 | fputc('\n',stderr); |
| 58 | } |
| 59 | |
| 60 | static void diag(adns_state ads, const char *fmt, ...) { |
| 61 | va_list al; |
| 62 | |
| 63 | va_start(al,fmt); |
| 64 | vdiag(ads,fmt,al); |
| 65 | va_end(al); |
| 66 | } |
| 67 | |
| 68 | static void addserver(adns_state ads, struct in_addr addr) { |
| 69 | int i; |
| 70 | struct server *ss; |
| 71 | |
| 72 | for (i=0; i<ads->nservers; i++) { |
| 73 | if (ads->servers[i].addr.s_addr == addr.s_addr) { |
| 74 | debug(ads,"duplicate nameserver %s ignored",inet_ntoa(addr)); |
| 75 | return; |
| 76 | } |
| 77 | } |
| 78 | |
| 79 | if (ads->nservers>=MAXSERVERS) { |
| 80 | diag(ads,"too many nameservers, ignoring %s",inet_ntoa(addr)); |
| 81 | return; |
| 82 | } |
| 83 | |
| 84 | ss= ads->servers+ads->nservers; |
| 85 | ss->addr= addr; |
| 86 | ss->state= server_disc; |
| 87 | ss->connw.head= ss->connw.tail= 0; |
| 88 | ads->nservers++; |
| 89 | } |
| 90 | |
| 91 | static void configparseerr(adns_state ads, const char *fn, int lno, |
| 92 | const char *fmt, ...) { |
| 93 | va_list al; |
| 94 | |
| 95 | if (ads->iflags & adns_if_noerrprint) return; |
| 96 | if (lno==-1) fprintf(stderr,"adns: %s: ",fn); |
| 97 | else fprintf(stderr,"adns: %s:%d: ",fn,lno); |
| 98 | va_start(al,fmt); |
| 99 | vfprintf(stderr,fmt,al); |
| 100 | va_end(al); |
| 101 | fputc('\n',stderr); |
| 102 | } |
| 103 | |
| 104 | static void ccf_nameserver(adns_state ads, const char *fn, int lno, const char *buf) { |
| 105 | struct in_addr ia; |
| 106 | |
| 107 | if (!inet_aton(buf,&ia)) { |
| 108 | configparseerr(ads,fn,lno,"invalid nameserver address `%s'",buf); |
| 109 | return; |
| 110 | } |
| 111 | debug(ads,"using nameserver %s",inet_ntoa(ia)); |
| 112 | addserver(ads,ia); |
| 113 | } |
| 114 | |
| 115 | static void ccf_search(adns_state ads, const char *fn, int lno, const char *buf) { |
| 116 | if (!buf) return; |
| 117 | diag(ads,"warning - `search' ignored FIXME"); |
| 118 | } |
| 119 | |
| 120 | static void ccf_sortlist(adns_state ads, const char *fn, int lno, const char *buf) { |
| 121 | diag(ads,"warning - `sortlist' ignored FIXME"); |
| 122 | } |
| 123 | |
| 124 | static void ccf_options(adns_state ads, const char *fn, int lno, const char *buf) { |
| 125 | if (!buf) return; |
| 126 | diag(ads,"warning - `options' ignored FIXME"); |
| 127 | } |
| 128 | |
| 129 | static void ccf_clearnss(adns_state ads, const char *fn, int lno, const char *buf) { |
| 130 | ads->nservers= 0; |
| 131 | } |
| 132 | |
| 133 | static const struct configcommandinfo { |
| 134 | const char *name; |
| 135 | void (*fn)(adns_state ads, const char *fn, int lno, const char *buf); |
| 136 | } configcommandinfos[]= { |
| 137 | { "nameserver", ccf_nameserver }, |
| 138 | { "domain", ccf_search }, |
| 139 | { "search", ccf_search }, |
| 140 | { "sortlist", ccf_sortlist }, |
| 141 | { "options", ccf_options }, |
| 142 | { "clearnameservers", ccf_clearnss }, |
| 143 | { 0 } |
| 144 | }; |
| 145 | |
| 146 | static int ctype_whitespace(int c) { return c==' ' || c=='\n' || c=='\t'; } |
| 147 | static int ctype_digit(int c) { return c>='0' && c<='9'; } |
| 148 | |
| 149 | static void readconfig(adns_state ads, const char *filename) { |
| 150 | char linebuf[2000], *p, *q; |
| 151 | FILE *file; |
| 152 | int lno, l, c; |
| 153 | const struct configcommandinfo *ccip; |
| 154 | |
| 155 | file= fopen(filename,"r"); |
| 156 | if (!file) { |
| 157 | if (errno == ENOENT) { |
| 158 | debug(ads,"configuration file `%s' does not exist",filename); |
| 159 | return; |
| 160 | } |
| 161 | diag(ads,"cannot open configuration file `%s': %s",filename,strerror(errno)); |
| 162 | return; |
| 163 | } |
| 164 | |
| 165 | for (lno=1; fgets(linebuf,sizeof(linebuf),file); lno++) { |
| 166 | l= strlen(linebuf); |
| 167 | if (!l) continue; |
| 168 | if (linebuf[l-1] != '\n' && !feof(file)) { |
| 169 | diag(ads,"%s:%d: line too long",filename,lno); |
| 170 | while ((c= getc(file)) != EOF && c != '\n') { } |
| 171 | if (c == EOF) break; |
| 172 | continue; |
| 173 | } |
| 174 | while (l>0 && ctype_whitespace(linebuf[l-1])) l--; |
| 175 | linebuf[l]= 0; |
| 176 | p= linebuf; |
| 177 | while (ctype_whitespace(*p)) p++; |
| 178 | if (*p == '#' || *p == '\n') continue; |
| 179 | q= p; |
| 180 | while (*q && !ctype_whitespace(*q)) q++; |
| 181 | for (ccip=configcommandinfos; |
| 182 | ccip->name && strncmp(ccip->name,p,q-p); |
| 183 | ccip++); |
| 184 | if (!ccip->name) { |
| 185 | diag(ads,"%s:%d: unknown configuration directive `%.*s'",filename,lno,q-p,p); |
| 186 | continue; |
| 187 | } |
| 188 | while (ctype_whitespace(*q)) q++; |
| 189 | ccip->fn(ads,filename,lno,q); |
| 190 | } |
| 191 | if (ferror(file)) { |
| 192 | diag(ads,"%s:%d: read error: %s",filename,lno,strerror(errno)); |
| 193 | } |
| 194 | fclose(file); |
| 195 | } |
| 196 | |
| 197 | static const char *instrum_getenv(adns_state ads, const char *envvar) { |
| 198 | const char *value; |
| 199 | |
| 200 | value= getenv(envvar); |
| 201 | if (!value) debug(ads,"environment variable %s not set",envvar); |
| 202 | else debug(ads,"environment variable %s set to `%s'",envvar,value); |
| 203 | return value; |
| 204 | } |
| 205 | |
| 206 | static void readconfigenv(adns_state ads, const char *envvar) { |
| 207 | const char *filename; |
| 208 | |
| 209 | if (ads->iflags & adns_if_noenv) { |
| 210 | debug(ads,"not checking environment variable `%s'",envvar); |
| 211 | return; |
| 212 | } |
| 213 | filename= instrum_getenv(ads,envvar); |
| 214 | if (filename) readconfig(ads,filename); |
| 215 | } |
| 216 | |
| 217 | int adns_init(adns_state *ads_r, adns_initflags flags) { |
| 218 | adns_state ads; |
| 219 | const char *res_options, *adns_res_options; |
| 220 | struct protoent *proto; |
| 221 | int r; |
| 222 | |
| 223 | ads= malloc(sizeof(*ads)); if (!ads) return errno; |
| 224 | ads->tosend.head= ads->tosend.tail= 0; |
| 225 | ads->timew.head= ads->timew.tail= 0; |
| 226 | ads->childw.head= ads->childw.tail= 0; |
| 227 | ads->output.head= ads->output.tail= 0; |
| 228 | ads->nextid= 0x311f; |
| 229 | ads->udpsocket= -1; |
| 230 | ads->qbufavail= 0; |
| 231 | ads->qbuf= 0; |
| 232 | ads->tcpbufavail= ads->tcpbufused= ads->tcpbufdone= 0; |
| 233 | ads->tcpbuf= 0; |
| 234 | ads->iflags= flags; |
| 235 | ads->nservers= 0; |
| 236 | ads->iflags= flags; |
| 237 | |
| 238 | res_options= instrum_getenv(ads,"RES_OPTIONS"); |
| 239 | adns_res_options= instrum_getenv(ads,"ADNS_RES_OPTIONS"); |
| 240 | ccf_options(ads,"RES_OPTIONS",-1,res_options); |
| 241 | ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options); |
| 242 | |
| 243 | readconfig(ads,"/etc/resolv.conf"); |
| 244 | readconfigenv(ads,"RES_CONF"); |
| 245 | readconfigenv(ads,"ADNS_RES_CONF"); |
| 246 | |
| 247 | ccf_options(ads,"RES_OPTIONS",-1,res_options); |
| 248 | ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options); |
| 249 | |
| 250 | ccf_search(ads,"LOCALDOMAIN",-1,instrum_getenv(ads,"LOCALDOMAIN")); |
| 251 | ccf_search(ads,"ADNS_LOCALDOMAIN",-1,instrum_getenv(ads,"ADNS_LOCALDOMAIN")); |
| 252 | |
| 253 | if (!ads->nservers) { |
| 254 | struct in_addr ia; |
| 255 | if (ads->iflags & adns_if_debug) |
| 256 | fprintf(stderr,"adns: no nameservers, using localhost\n"); |
| 257 | ia.s_addr= INADDR_LOOPBACK; |
| 258 | addserver(ads,ia); |
| 259 | } |
| 260 | |
| 261 | proto= getprotobyname("udp"); if (!proto) { r= ENOPROTOOPT; goto x_free; } |
| 262 | ads->udpsocket= socket(AF_INET,SOCK_DGRAM,proto->p_proto); |
| 263 | if (!ads->udpsocket) { r= errno; goto x_closeudp; } |
| 264 | |
| 265 | *ads_r= ads; |
| 266 | return 0; |
| 267 | |
| 268 | x_closeudp: |
| 269 | close(ads->udpsocket); |
| 270 | x_free: |
| 271 | free(ads); |
| 272 | return r; |
| 273 | } |
| 274 | |
| 275 | static void query_fail(adns_state ads, adns_query qu, adns_status stat) { |
| 276 | adns_answer *ans; |
| 277 | |
| 278 | ans= qu->answer; |
| 279 | if (!ans) ans= malloc(sizeof(*qu->answer)); |
| 280 | if (ans) { |
| 281 | ans->status= stat; |
| 282 | ans->cname= 0; |
| 283 | ans->type= qu->type; |
| 284 | ans->nrrs= 0; |
| 285 | } |
| 286 | qu->answer= ans; |
| 287 | qu->id= -1; |
| 288 | LIST_LINK_TAIL(ads->output,qu); |
| 289 | } |
| 290 | |
| 291 | int adns_finish(adns_state ads) { |
| 292 | abort(); /* FIXME */ |
| 293 | } |
| 294 | |
| 295 | static void autosys(adns_state ads, struct timeval now) { |
| 296 | if (ads->iflags & adns_if_noautosys) return; |
| 297 | adns_callback(ads,-1,0,0,0); |
| 298 | } |
| 299 | |
| 300 | void adns_cancel(adns_state ads, adns_query query) { |
| 301 | abort(); /* FIXME */ |
| 302 | } |
| 303 | |
| 304 | static int callb_checkfd(int maxfd, const fd_set *fds, int fd) { |
| 305 | return maxfd<0 || !fds ? 1 : |
| 306 | fd<maxfd && FD_ISSET(fd,fds); |
| 307 | } |
| 308 | |
| 309 | int adns_callback(adns_state ads, int maxfd, |
| 310 | const fd_set *readfds, const fd_set *writefds, |
| 311 | const fd_set *exceptfds) { |
| 312 | int skip, dgramlen, count; |
| 313 | enum adns__tcpstate oldtcpstate; |
| 314 | |
| 315 | count= 0; |
| 316 | oldtcpstate= ads->tcpstate; |
| 317 | |
| 318 | if (ads->tcpstate == server_connecting) { |
| 319 | if (callb_checkfd(maxfd,writefds,ads->tcpsocket)) { |
| 320 | count++; |
| 321 | assert(ads->tcprecv.used==0); |
| 322 | vbuf_ensure(&ads->tcprecv,1); |
| 323 | if (ads->tcprecv.buf) { |
| 324 | r= read(ads->tcpsocket,&ads->tcprecv.buf,1); |
| 325 | if (r==0 || (r<0 && (errno==EAGAIN || errno==EWOULDBLOCK))) { |
| 326 | diag("nameserver %s TCP connection made", |
| 327 | inet_ntoa(ads->servers[ads->tcpserver].addr)); |
| 328 | ads->tcpstate= server_connected; |
| 329 | } else if (r>0) { |
| 330 | tcpserver_broken(ads,"connect/read","sent data before first request"); |
| 331 | } else if (errno!=EINTR) { |
| 332 | tcpserver_broken(ads,"connect",strerror(errno)); |
| 333 | } |
| 334 | } |
| 335 | } |
| 336 | } |
| 337 | if (ads->tcpstate == server_connected) { |
| 338 | if (oldtcpstate == server_connected) |
| 339 | count+= callb_checkfd(maxfd,readfds,ads->tcpsocket) + |
| 340 | callb_checkfd(maxfd,exceptfds,ads->tcpsocket) + |
| 341 | (ads->tcpsend.used && callb_checkfd(maxfd,writefds,ads->tcpsocket)); |
| 342 | if (oldtcpstate != server_connected || callb_checkfd(maxfd,readfds,ads->tcpsocket)) { |
| 343 | skip= 0; |
| 344 | for (;;) { |
| 345 | if (ads->tcprecv.used<skip+2) { |
| 346 | want= 2; |
| 347 | } else { |
| 348 | dgramlen= (ads->tcprecv.buf[skip]<<8) | ads->tcprecv.buf[skip+1]; |
| 349 | if (ads->tcprecv.used<skip+2+dgramlen) { |
| 350 | want= 2+dgramlen; |
| 351 | } else { |
| 352 | procdgram(ads,ads->tcprecv.buf+skip+2,dgramlen,-1); |
| 353 | skip+= 2+dgramlen; continue; |
| 354 | } |
| 355 | } |
| 356 | Ads->tcprecv.used -= skip; |
| 357 | memmove(ads->tcprecv.buf,ads->tcprecv.buf+skip,ads->tcprecv.used); |
| 358 | vbuf_ensure(&ads->tcprecv,want); |
| 359 | if (ads->tcprecv.used >= ads->tcprecv.avail) break; |
| 360 | r= read(ads->tcpsocket, |
| 361 | ads->tcprecv.buf+ads->tcprecv.used, |
| 362 | ads->tcprecv.avail-ads->tcprecv.used); |
| 363 | if (r>0) { |
| 364 | ads->tcprecv.used+= r; |
| 365 | } else { |
| 366 | if (r<0) { |
| 367 | if (errno==EAGAIN || errno==EWOULDBLOCK || errno==ENOMEM) break; |
| 368 | if (errno==EINTR) continue; |
| 369 | } |
| 370 | tcpserver_broken(ads->tcpserver,"read",r?strerror(errno):"closed"); |
| 371 | break; |
| 372 | } |
| 373 | } |
| 374 | } else if (callb_checkfd(maxfd,exceptfds,ads->tcpsocket)) { |
| 375 | tcpserver_broken(ads->tcpserver,"select","exceptional condition detected"); |
| 376 | } else if (ads->tcpsend.used && callb_checkfd(maxfd,writefds,ads->tcpsocket)) { |
| 377 | r= write(ads->tcpsocket,ads->tcpsend.buf,ads->tcpsend.used); |
| 378 | if (r<0) { |
| 379 | if (errno!=EAGAIN && errno!=EWOULDBLOCK && errno!=ENOMEM && errno!=EINTR) { |
| 380 | tcpserver_broken(ads->tcpserver,"write",strerror(errno)); |
| 381 | } |
| 382 | } else if (r>0) { |
| 383 | ads->tcpsend.used -= r; |
| 384 | memmove(ads->tcpsend.buf,ads->tcpsend.buf+r,ads->tcpsend.used); |
| 385 | } |
| 386 | } |
| 387 | } |
| 388 | |
| 389 | if ( |
| 390 | break; |
| 391 | |
| 392 | |
| 393 | } |
| 394 | |
| 395 | tcpserver_broken( |
| 396 | |
| 397 | if (ads- |
| 398 | used= 0; |
| 399 | for (;;) { |
| 400 | vbuf_ensure(&ads->tcprecv,2); |
| 401 | vbuf_ensure(&ads->tcprecv, |
| 402 | if (ads->tcprecv.avail<2) break; |
| 403 | if (ads->tcprecv.used |
| 404 | |
| 405 | if (ads->tcprecv.used<2 && ads->tcprecv.avail |
| 406 | if (ads->tcprecv.used<2 && ads->tcprecv.avail |
| 407 | r= read(ads->tcpsocket, |
| 408 | if (adns->tcprecv.used<2) { |
| 409 | if ( |
| 410 | |
| 411 | if (ads->tcpstate != server_disc) { |
| 412 | |
| 413 | |
| 414 | } |
| 415 | if (maxfd<0 || !readfds || (FD_ISSET |
| 416 | ads-> |
| 417 | |
| 418 | abort(); /* FIXME */ |
| 419 | } |
| 420 | diag("nameserver #%d (%s) TCP connection died: %s", |
| 421 | inet_ntoa(ads->servers[tcpserver].addr), |
| 422 | |
| 423 | static void inter_maxto(struct timeval **tv_io, struct timeval *tvbuf, |
| 424 | struct timeval maxto) { |
| 425 | struct timeval rbuf; |
| 426 | |
| 427 | rbuf= *tv_io; |
| 428 | if (!rbuf) { *tvbuf= maxto; *tv_io= tvbuf; return; } |
| 429 | if (timercmp(rbuf,&maxto,>)) *rbuf= maxto; |
| 430 | } |
| 431 | |
| 432 | static void inter_maxtoabs(struct timeval **tv_io, struct timeval *tvbuf, |
| 433 | struct timeval now, struct timeval maxtime) { |
| 434 | ldiv_t dr; |
| 435 | |
| 436 | maxtime.tv_sec -= (now.tv_sec-1); |
| 437 | maxtime.tv_usec += (1000-now.tv_usec); |
| 438 | dr= ldiv(maxtime.tv_usec,1000); |
| 439 | maxtime.tv_sec += dr.quot; |
| 440 | maxtime.tv_usec -= dr.rem; |
| 441 | inter_maxto(tv_io,tvbuf,maxtime); |
| 442 | } |
| 443 | |
| 444 | static void localresourcerr(struct timeval **tv_io, struct timeval *tvbuf, |
| 445 | const char *syscall) { |
| 446 | struct timeval tvto_lr; |
| 447 | |
| 448 | diag(ads,"local system resources scarce (during %s): %s",syscall,strerror(errno)); |
| 449 | timerclear(&tvto_lr); timevaladd(&tvto_lr,LOCALRESOURCEMS); |
| 450 | inter_maxto(tv_io, tvbuf, tvto_lr); |
| 451 | return; |
| 452 | } |
| 453 | |
| 454 | static inline void timevaladd(struct timeval *tv_io, long ms) { |
| 455 | struct timeval tmp; |
| 456 | assert(ms>=0); |
| 457 | tmp= *tv_io; |
| 458 | tmp.tv_usec += (ms%1000)*1000; |
| 459 | tmp.tv_sec += ms/1000; |
| 460 | if (tmp.tv_usec >= 1000) { tmp.tv_sec++; tmp.tv_usec -= 1000; } |
| 461 | *tv_io= tmp; |
| 462 | } |
| 463 | |
| 464 | static void inter_addfd(int *maxfd, fd_set *fds, int fd) { |
| 465 | if (fd>=*maxfd) *maxfd= fd+1; |
| 466 | FD_SET(fd,fds); |
| 467 | } |
| 468 | |
| 469 | void adns_interest(adns_state ads, int *maxfd, |
| 470 | fd_set *readfds, fd_set *writefds, fd_set *exceptfds, |
| 471 | struct timeval **tv_io, struct timeval *tvbuf) { |
| 472 | struct timeval now; |
| 473 | adns_query qu; |
| 474 | int r; |
| 475 | |
| 476 | r= gettimeofday(&now,0); |
| 477 | if (r) { localresourcerr(tv_io,tvbuf,"gettimeofday"); return; } |
| 478 | |
| 479 | for (qu= ads->timew; qu; qu= nqu) { |
| 480 | nqu= qu->next; |
| 481 | if (timercmp(&now,qu->timeout,>)) { |
| 482 | DLIST_UNLINK(ads->timew,qu); |
| 483 | if (qu->nextudpserver == -1) { |
| 484 | query_fail(ads,qu,adns_s_notresponding); |
| 485 | } else { |
| 486 | DLIST_LINKTAIL(ads->tosend,qu); |
| 487 | } |
| 488 | } else { |
| 489 | inter_maxtoabs(tv_io,tvbuf,now,qu->timeout); |
| 490 | } |
| 491 | } |
| 492 | |
| 493 | for (qu= ads->tosend; qu; qu= nqu) { |
| 494 | nqu= qu->next; |
| 495 | quproc_tosend(ads,qu,now); |
| 496 | } |
| 497 | |
| 498 | inter_addfd(maxfd,readfds,ads->udpsocket); |
| 499 | switch (ads->tcpstate) { |
| 500 | case server_disc: |
| 501 | break; |
| 502 | case server_connecting: |
| 503 | inter_addfd(maxfd,writefds,ads->tcpsocket); |
| 504 | break; |
| 505 | case server_connected: |
| 506 | inter_addfd(maxfd,readfds,ads->tcpsocket); |
| 507 | inter_addfd(maxfd,exceptfds,ads->tcpsocket); |
| 508 | if (ads->opbufused) inter_addfd(maxfd,writefds,ads->tcpsocket); |
| 509 | default: |
| 510 | abort(); |
| 511 | } |
| 512 | |
| 513 | } |
| 514 | |
| 515 | static int internal_check(adns_state ads, |
| 516 | adns_query *query_io, |
| 517 | adns_answer **answer, |
| 518 | void **context_r) { |
| 519 | adns_query qu; |
| 520 | |
| 521 | qu= *query_io; |
| 522 | if (!qu) { |
| 523 | if (!ads->output.head) return EWOULDBLOCK; |
| 524 | qu= ads->output.head; |
| 525 | } else { |
| 526 | if (qu->id>=0) return EWOULDBLOCK; |
| 527 | } |
| 528 | LIST_UNLINK(ads->output,qu); |
| 529 | *answer= qu->answer; |
| 530 | if (context_r) *context_r= qu->context; |
| 531 | free(qu); |
| 532 | return 0; |
| 533 | } |
| 534 | |
| 535 | int adns_wait(adns_state ads, |
| 536 | adns_query *query_io, |
| 537 | adns_answer **answer_r, |
| 538 | void **context_r) { |
| 539 | int r, maxfd, rsel, rcb; |
| 540 | fd_set readfds, writefds, exceptfds; |
| 541 | struct timeval tvbuf, *tvp; |
| 542 | |
| 543 | for (;;) { |
| 544 | r= internal_check(ads,query_io,answer_r,context_r); |
| 545 | if (r && r != EWOULDBLOCK) return r; |
| 546 | FD_ZERO(&readfds); FD_ZERO(&writefds); FD_ZERO(&exceptfds); |
| 547 | maxfd= 0; tvp= 0; |
| 548 | adns_interest(ads,&maxfd,&readfds,&writefds,&exceptfds,&tvp,&tvbuf); |
| 549 | rsel= select(maxfd,&readfds,&writefds,&exceptfds,tvp); |
| 550 | if (rsel==-1) return r; |
| 551 | rcb= adns_callback(ads,maxfd,&readfds,&writefds,&exceptfds); |
| 552 | assert(rcb==rsel); |
| 553 | } |
| 554 | } |
| 555 | |
| 556 | int adns_check(adns_state ads, |
| 557 | adns_query *query_io, |
| 558 | adns_answer **answer_r, |
| 559 | void **context_r) { |
| 560 | autosys(ads); |
| 561 | return internal_check(ads,query_io,answer_r,context_r); |
| 562 | } |
| 563 | |
| 564 | int adns_synchronous(adns_state ads, |
| 565 | const char *owner, |
| 566 | adns_rrtype type, |
| 567 | adns_queryflags flags, |
| 568 | adns_answer **answer_r) { |
| 569 | adns_query qu; |
| 570 | int r; |
| 571 | |
| 572 | r= adns_submit(ads,owner,type,flags,0,&qu); |
| 573 | if (r) return r; |
| 574 | |
| 575 | do { |
| 576 | r= adns_wait(ads,&qu,answer_r,0); |
| 577 | } while (r==EINTR); |
| 578 | if (r) adns_cancel(ads,qu); |
| 579 | return r; |
| 580 | } |
| 581 | |
| 582 | static adns_status mkquery(adns_state ads, const char *owner, int ol, int id, |
| 583 | adns_rrtype type, adns_queryflags flags, int *qml_r) { |
| 584 | int ll, c, nlabs, qbufreq; |
| 585 | unsigned char label[255], *nqbuf; |
| 586 | const char *p, *pe; |
| 587 | |
| 588 | #define MKQUERY_ADDB(b) *nqbuf++= (b) |
| 589 | #define MKQUERY_ADDW(w) (MKQUERY_ADDB(((w)>>8)&0x0ff), MKQUERY_ADDB((w)&0x0ff)) |
| 590 | |
| 591 | qbufreq= 12+strlen(owner)+3; |
| 592 | if (ads->qbufavail < qbufreq) { |
| 593 | nqbuf= realloc(ads->qbuf,qbufreq); |
| 594 | if (!nqbuf) return adns_s_nolocalmem; |
| 595 | ads->qbuf= nqbuf; ads->qbufavail= qbufreq; |
| 596 | } |
| 597 | nqbuf= ads->qbuf; |
| 598 | |
| 599 | MKQUERY_ADDW(id); |
| 600 | MKQUERY_ADDB(0x01); /* QR=Q(0), OPCODE=QUERY(0000), !AA, !TC, RD */ |
| 601 | MKQUERY_ADDB(0x00); /* !RA, Z=000, RCODE=NOERROR(0000) */ |
| 602 | MKQUERY_ADDW(1); /* QDCOUNT=1 */ |
| 603 | MKQUERY_ADDW(0); /* ANCOUNT=0 */ |
| 604 | MKQUERY_ADDW(0); /* NSCOUNT=0 */ |
| 605 | MKQUERY_ADDW(0); /* ARCOUNT=0 */ |
| 606 | p= owner; pe= owner+ol; |
| 607 | nlabs= 0; |
| 608 | if (!*p) return adns_s_invaliddomain; |
| 609 | do { |
| 610 | ll= 0; |
| 611 | while (p!=pe && (c= *p++)!='.') { |
| 612 | if (c=='\\') { |
| 613 | if (!(flags & adns_f_anyquote)) return adns_s_invaliddomain; |
| 614 | if (ctype_digit(p[0])) { |
| 615 | if (ctype_digit(p[1]) && ctype_digit(p[2])) { |
| 616 | c= (*p++ - '0')*100 + (*p++ - '0')*10 + (*p++ - '0'); |
| 617 | if (c >= 256) return adns_s_invaliddomain; |
| 618 | } else { |
| 619 | return adns_s_invaliddomain; |
| 620 | } |
| 621 | } else if (!(c= *p++)) { |
| 622 | return adns_s_invaliddomain; |
| 623 | } |
| 624 | } |
| 625 | if (!(flags & adns_f_anyquote)) { |
| 626 | if ((c >= '0' && c <= '9') || c == '-') { |
| 627 | if (!ll) return adns_s_invaliddomain; |
| 628 | } else if ((c < 'a' || c > 'z') && (c < 'A' && c > 'Z')) { |
| 629 | return adns_s_invaliddomain; |
| 630 | } |
| 631 | } |
| 632 | if (ll == sizeof(label)) return adns_s_invaliddomain; |
| 633 | label[ll++]= c; |
| 634 | } |
| 635 | if (!ll) return adns_s_invaliddomain; |
| 636 | if (nlabs++ > 63) return adns_s_invaliddomain; |
| 637 | MKQUERY_ADDB(ll); |
| 638 | memcpy(nqbuf,label,ll); nqbuf+= ll; |
| 639 | } while (p!=pe); |
| 640 | |
| 641 | MKQUERY_ADDB(0); |
| 642 | MKQUERY_ADDW(type & adns__rrt_typemask); /* QTYPE */ |
| 643 | MKQUERY_ADDW(1); /* QCLASS=IN */ |
| 644 | |
| 645 | *qml_r= nqbuf - ads->qbuf; |
| 646 | |
| 647 | return adns_s_ok; |
| 648 | } |
| 649 | |
| 650 | static adns_query allocquery(adns_state ads, const char *owner, int ol, |
| 651 | int qml, int id, adns_rrtype type, |
| 652 | adns_queryflags flags, void *context) { |
| 653 | adns_query qu; |
| 654 | unsigned char *qm; |
| 655 | |
| 656 | qu= malloc(sizeof(*qu)+ol+1+qml); if (!qu) return 0; |
| 657 | qu->next= qu->back= qu->parent= 0; |
| 658 | qu->children.head= qu->children.tail= 0; |
| 659 | qu->siblings.next= qu->siblings.back= 0; |
| 660 | qu->id= id; |
| 661 | qu->type= type; |
| 662 | qu->answer= 0; |
| 663 | qu->flags= flags; |
| 664 | qu->context= context; |
| 665 | qu->udpretries= 0; |
| 666 | qu->sentudp= qu->senttcp= 0; |
| 667 | qu->nextserver= 0; |
| 668 | memcpy(qu->owner,owner,ol); qu->owner[ol]= 0; |
| 669 | qu->querymsg= qm= qu->owner+ol+1; |
| 670 | memcpy(qm,ads->qbuf,qml); |
| 671 | qu->querylen= qml; |
| 672 | return qu; |
| 673 | } |
| 674 | |
| 675 | static int failsubmit(adns_state ads, void *context, adns_query *query_r, |
| 676 | adns_rrtype type, adns_queryflags flags, |
| 677 | int id, adns_status stat) { |
| 678 | adns_query qu; |
| 679 | |
| 680 | qu= allocquery(ads,0,0,0,id,type,flags,context); if (!qu) return errno; |
| 681 | query_fail(ads,qu,stat); |
| 682 | *query_r= qu; |
| 683 | return 0; |
| 684 | } |
| 685 | |
| 686 | static void quproc_tosend(adns_state ads, adns_query qu, struct timeval now) { |
| 687 | /* Query must be on the `tosend' queue, and guarantees to remove it. */ |
| 688 | struct sockaddr_in servaddr; |
| 689 | int serv; |
| 690 | |
| 691 | if (qu->nextudpserver != -1) { |
| 692 | if (qu->udpretries >= UDPMAXRETRIES) { |
| 693 | DLIST_UNLINK(ads->tosend,qu); |
| 694 | query_fail(ads,qu,adns_s_notresponding); |
| 695 | return; |
| 696 | } |
| 697 | serv= qu->nextudpserver; |
| 698 | memset(&servaddr,0,sizeof(servaddr)); |
| 699 | servaddr.sin_family= AF_INET; |
| 700 | servaddr.sin_addr= ads->servers[serv].addr; |
| 701 | servaddr.sin_port= htons(53); |
| 702 | r= sendto(ads->udpsocket,qu->querymsg,qu->querylen,0,&servaddr,sizeof(servaddr)); |
| 703 | if (r<0 && errno == EMSGSIZE) { |
| 704 | qu->nextudpserver= -1; |
| 705 | } else { |
| 706 | if (r<0) { |
| 707 | diag("sendto %s failed: %s",inet_ntoa(servaddr.sin_addr),strerror(errno)); |
| 708 | } |
| 709 | DLIST_UNLINK(ads->tosend,qu); |
| 710 | timevaladd(&now,UDPRETRYMS); |
| 711 | qu->timeout= now; |
| 712 | qu->sentudp |= (1<<serv); |
| 713 | qu->nextudpserver= (serv+1)%ads->nservers; |
| 714 | qu->udpretries++; |
| 715 | DLIST_LINKTAIL(ads->timew,qu); |
| 716 | return; |
| 717 | } |
| 718 | } |
| 719 | |
| 720 | for (;;) { |
| 721 | serv= tcpserver_get(ads); |
| 722 | if (serv<0) { r=0; break; } |
| 723 | if (ads->opbufused) { r=0; break; } |
| 724 | r= write(ads->tcpsocket,qu->querymsg,qu->querylen); |
| 725 | if (r >= 0) break; |
| 726 | if (errno == EAGAIN || errno == EINTR || errno == ENOSPC || |
| 727 | errno == ENOBUFS || errno == ENOMEM) { |
| 728 | r= 0; break; |
| 729 | } |
| 730 | tcpserver_broken(serv); |
| 731 | } |
| 732 | if (r < qu->querylen) { |
| 733 | newopbufused= qu->opbufused + (qu->querylen-r); |
| 734 | if (newopbufused > ads->opbufavail) { |
| 735 | newopbufavail= ads->newopbufused<<1; |
| 736 | newopbuf= realloc(newopbufavail); |
| 737 | if (!newopbuf) { |
| 738 | DLIST_UNLINK(ads->tosend,qu); |
| 739 | query_fail(ads,qu,adns_s_nolocalmem); |
| 740 | return; |
| 741 | } |
| 742 | ads->opbuf= newopbuf; |
| 743 | ads->opbufavail= newopbufavail; |
| 744 | } |
| 745 | memcpy(ads->opbuf+ads->opbufused,qu->querymsg+r,qu->querylen-r); |
| 746 | ads->opbufused= newopbufused; |
| 747 | } |
| 748 | DLIST_UNLINK(ads->tosend,qu); |
| 749 | timevaladd(&now,TCPMS); |
| 750 | qu->timeout= now; |
| 751 | qu->senttcp |= (1<<qu->nextserver); |
| 752 | DLIST_LINKTAIL(ads->timew,qu); |
| 753 | } |
| 754 | |
| 755 | int adns_submit(adns_state ads, |
| 756 | const char *owner, |
| 757 | adns_rrtype type, |
| 758 | adns_queryflags flags, |
| 759 | void *context, |
| 760 | adns_query *query_r) { |
| 761 | adns_query qu; |
| 762 | adns_status stat; |
| 763 | int ol, id, qml; |
| 764 | |
| 765 | id= ads->nextid++; |
| 766 | |
| 767 | ol= strlen(owner); |
| 768 | if (ol<=1 || ol>MAXDNAME+1) |
| 769 | return failsubmit(ads,context,query_r,type,flags,id,adns_s_invaliddomain); |
| 770 | if (owner[ol-1]=='.' && owner[ol-2]!='\\') { flags &= ~adns_f_search; ol--; } |
| 771 | |
| 772 | stat= mkquery(ads,owner,ol,id,type,flags,&qml); |
| 773 | if (stat) return failsubmit(ads,context,query_r,type,flags,id,stat); |
| 774 | |
| 775 | qu= allocquery(ads,owner,ol,qml,id,type,flags,context); if (!qu) return errno; |
| 776 | if (qu->flags & adns_f_usevc) qu->udpretries= -1; |
| 777 | LIST_LINK_TAIL(ads->tosend,qu); |
| 778 | |
| 779 | r= gettimeofday(&now,0); if (r) return; |
| 780 | quproc_tosend(ads,qu,now); |
| 781 | autosys(ads,now); |
| 782 | |
| 783 | *query_r= qu; |
| 784 | return 0; |
| 785 | } |