int dns_domain_equal(const unsigned char *dn1, const unsigned char *dn2) { long long len; len = dns_domain_length(dn1); if (len != dns_domain_length(dn2)) return 0; return !case_diffb(dn1, len, dn2); }
int response_addname(char *d) { unsigned int dlen; unsigned int i; char buf[2]; dlen = dns_domain_length(d); while (*d) { for (i = 0;i < name_num;++i) if (dns_domain_equal(d,name[i])) { uint16_pack_big(buf,49152 + name_ptr[i]); return response_addbytes(buf,2); } if (dlen <= 128) if (name_num < NAMES) { byte_copy(name[name_num],dlen,d); name_ptr[name_num] = response_len; ++name_num; } i = (unsigned char) *d; ++i; if (!response_addbytes(d,i)) return 0; d += i; dlen -= i; } return response_addbytes(d,1); }
int dns_transmit_start(struct dns_transmit *d,const char servers[64],int flagrecursive,const char *q,const char qtype[2],const char localip[4]) { unsigned int len; dns_transmit_free(d); errno = error_io; len = dns_domain_length(q); d->querylen = len + 18; d->query = alloc(d->querylen); if (!d->query) return -1; uint16_pack_big(d->query,len + 16); byte_copy(d->query + 2,12,flagrecursive ? "\0\0\1\0\0\1\0\0\0\0\0\0" : "\0\0\0\0\0\1\0\0\0\0\0\0gcc-bug-workaround"); byte_copy(d->query + 14,len,q); byte_copy(d->query + 14 + len,2,qtype); byte_copy(d->query + 16 + len,2,DNS_C_IN); byte_copy(d->qtype,2,qtype); d->servers = servers; byte_copy(d->localip,4,localip); d->udploop = flagrecursive ? 1 : 0; if (len + 16 > 512) return firsttcp(d); return firstudp(d); }
void doname(stralloc *sa) { static char *d; dpos = dns_packet_getname(data,dlen,dpos,&d); if (!dpos) die_cdbread(); if (!stralloc_catb(sa,d,dns_domain_length(d))) nomem(); }
static int doit(char *q,char qtype[2],char ip[4]) { int r; uint32 dlen; unsigned int qlen; qlen = dns_domain_length(q); if (qlen > 255) return 0; /* impossible */ if (byte_diff(qtype,2,DNS_T_A) && byte_diff(qtype,2,DNS_T_ANY)) goto REFUSE; key[0] = '%'; byte_copy(key + 1,4,ip); r = cdb_find(&c,key,5); if (!r) r = cdb_find(&c,key,4); if (!r) r = cdb_find(&c,key,3); if (!r) r = cdb_find(&c,key,2); if (r == -1) return 0; key[0] = '+'; byte_zero(key + 1,2); if (r && (cdb_datalen(&c) == 2)) if (cdb_read(&c,key + 1,2,cdb_datapos(&c)) == -1) return 0; byte_copy(key + 3,qlen,q); case_lowerb(key + 3,qlen + 3); r = cdb_find(&c,key,qlen + 3); if (!r) { byte_zero(key + 1,2); r = cdb_find(&c,key,qlen + 3); } if (!r) goto REFUSE; if (r == -1) return 0; dlen = cdb_datalen(&c); if (dlen > 512) dlen = 512; if (cdb_read(&c,data,dlen,cdb_datapos(&c)) == -1) return 0; dns_sortip(data,dlen); if (dlen > 12) dlen = 12; while (dlen >= 4) { dlen -= 4; if (!response_rstart(q,DNS_T_A,"\0\0\0\5")) return 0; if (!response_addbytes(data + dlen,4)) return 0; response_rfinish(RESPONSE_ANSWER); } return 1; REFUSE: response[2] &= ~4; response[3] &= ~15; response[3] |= 5; return 1; }
void doname (stralloc *sa) { static char *d = NULL; dpos = dns_packet_getname (data, dlen, dpos, &d); if (!dpos) err (-1, "could not read from file `data.cdb'"); if (!stralloc_catb (sa, d, dns_domain_length (d))) err (-1, "could not allocate enough memory"); }
void rr_finish(const char *owner) { if (byte_equal(owner,2,"\1*")) { owner += 2; result.s[2] -= 19; } if (!stralloc_copyb(&key,owner,dns_domain_length(owner))) nomem(); case_lowerb(key.s,key.len); if (cdb_make_add(&cdb,key.s,key.len,result.s,result.len) == -1) die_datatmp(); }
static int doit(void) { unsigned int pos; char header[12]; char qtype[2]; char qclass[2]; if (len >= sizeof buf) goto NOQ; pos = dns_packet_copy(buf,len,0,header,12); if (!pos) goto NOQ; if (header[2] & 128) goto NOQ; if (header[4]) goto NOQ; if (header[5] != 1) goto NOQ; pos = dns_packet_getname(buf,len,pos,&q); if (!pos) goto NOQ; pos = dns_packet_copy(buf,len,pos,qtype,2); if (!pos) goto NOQ; pos = dns_packet_copy(buf,len,pos,qclass,2); if (!pos) goto NOQ; if (!response_query(q,qtype,qclass)) goto NOQ; response_id(header); if (byte_equal(qclass,2,DNS_C_IN)) response[2] |= 4; else if (byte_diff(qclass,2,DNS_C_ANY)) goto WEIRDCLASS; response[3] &= ~128; if (!(header[2] & 1)) response[2] &= ~1; if (header[2] & 126) goto NOTIMP; if (byte_equal(qtype,2,DNS_T_AXFR)) goto NOTIMP; case_lowerb(q,dns_domain_length(q)); if (!respond(q,qtype,ip)) { qlog(ip,port,header,q,qtype," - "); return 0; } qlog(ip,port,header,q,qtype," + "); return 1; NOTIMP: response[3] &= ~15; response[3] |= 4; qlog(ip,port,header,q,qtype," I "); return 1; WEIRDCLASS: response[3] &= ~15; response[3] |= 1; qlog(ip,port,header,q,qtype," C "); return 1; NOQ: qlog(ip,port,"\0\0","","\0\0"," / "); return 0; }
int dns_domain_copy(unsigned char **out, const unsigned char *in) { long long len; unsigned char *x; len = dns_domain_length(in); x = alloc(len); if (!x) return 0; byte_copy(x, len, in); if (*out) alloc_free(*out); *out = x; return 1; }
static int roots_find(char *q) { int i; int j; i = 0; while (i < data.len) { j = dns_domain_length(data.s + i); if (dns_domain_equal(data.s + i,q)) return i + j; i += j; i += 64; } return -1; }
void rr_finish (const char *owner) { if (byte_equal (owner, 2, "\1*")) { owner += 2; result.s[2] -= 19; } if (!stralloc_copyb (&key, owner, dns_domain_length (owner))) err (-1, "could not allocate enough memory"); case_lowerb (key.s, key.len); if (cdb_make_add (&cdb, key.s, key.len, result.s, result.len) == -1) errx (-1, "could not create file `data.tmp'"); }
static int find(char *d,int flagwild) { int r; char ch; struct tai cutoff; char ttd[8]; char ttlstr[4]; char recordloc[2]; double newttl; for (;;) { r = cdb_findnext(&c,d,dns_domain_length(d)); if (r <= 0) return r; dlen = cdb_datalen(&c); if (dlen > sizeof data) return -1; if (cdb_read(&c,data,dlen,cdb_datapos(&c)) == -1) return -1; dpos = dns_packet_copy(data,dlen,0,type,2); if (!dpos) return -1; dpos = dns_packet_copy(data,dlen,dpos,&ch,1); if (!dpos) return -1; if ((ch == '=' + 1) || (ch == '*' + 1)) { --ch; dpos = dns_packet_copy(data,dlen,dpos,recordloc,2); if (!dpos) return -1; if (byte_diff(recordloc,2,clientloc)) continue; } if (flagwild != (ch == '*')) continue; dpos = dns_packet_copy(data,dlen,dpos,ttlstr,4); if (!dpos) return -1; uint32_unpack_big(ttlstr,&ttl); dpos = dns_packet_copy(data,dlen,dpos,ttd,8); if (!dpos) return -1; if (byte_diff(ttd,8,"\0\0\0\0\0\0\0\0")) { tai_unpack(ttd,&cutoff); if (ttl == 0) { if (tai_less(&cutoff,&now)) continue; tai_sub(&cutoff,&cutoff,&now); newttl = tai_approx(&cutoff); if (newttl <= 2.0) newttl = 2.0; if (newttl >= 3600.0) newttl = 3600.0; ttl = newttl; } else if (!tai_less(&cutoff,&now)) continue; } return 1; } }
static int init2(DIR *dir) { direntry *d; const char *fqdn; static char *q; static stralloc text; char servers[64]; int serverslen; int i; int j; for (;;) { errno = 0; d = readdir(dir); if (!d) { if (errno) return 0; return 1; } if (d->d_name[0] != '.') { if (openreadclose(d->d_name,&text,32) != 1) return 0; if (!stralloc_append(&text,"\n")) return 0; fqdn = d->d_name; if (str_equal(fqdn,"@")) fqdn = "."; if (!dns_domain_fromdot(&q,fqdn,str_len(fqdn))) return 0; serverslen = 0; j = 0; for (i = 0;i < text.len;++i) if (text.s[i] == '\n') { if (serverslen <= 60) if (ip4_scan(text.s + j,servers + serverslen)) serverslen += 4; j = i + 1; } byte_zero(servers + serverslen,64 - serverslen); if (!stralloc_catb(&data,q,dns_domain_length(q))) return 0; if (!stralloc_catb(&data,servers,64)) return 0; } } }
int main(int argc,char **argv) { uint16 u16; if (!*argv) usage(); if (!*++argv) usage(); if (!parsetype(*argv,type)) usage(); if (!*++argv) usage(); if (!dns_domain_fromdot(&q,*argv,str_len(*argv))) oops(); if (*++argv) { if (!ip4_scan(*argv,ip)) usage(); } if (!stralloc_copys(&out,"")) oops(); /* uint16_unpack_big(type,&u16); if (!stralloc_catulong0(&out,u16,0)) oops(); if (!stralloc_cats(&out," ")) oops(); if (!dns_domain_todot_cat(&out,q)) oops(); if (!stralloc_cats(&out,":\n")) oops(); */ if (!response_query(q,type,DNS_C_IN)) oops(); response[3] &= ~128; response[2] &= ~1; response[2] |= 4; case_lowerb(q,dns_domain_length(q)); if (byte_equal(type,2,DNS_T_AXFR)) { response[3] &= ~15; response[3] |= 4; } else if (!respond(q,type,ip)) goto DONE; if (!printpacket_cat(&out,response,response_len)) oops(); DONE: buffer_putflush(buffer_1,out.s,out.len); _exit(0); }
int main () { stralloc out ={0}; stralloc sa ={0}; char ip[4]; char *dn =0; stralloc_copys(&sa, "abcdefg"); dns_ip4(&out, &sa); dns_ip4_qualify(&out, &sa, &sa); dns_name4(&out, ip); dns_mx(&out, &sa); dns_txt(&out, &sa); dns_domain_length(sa.s); dns_domain_equal(sa.s, sa.s); dns_domain_copy(&dn, sa.s); dns_domain_fromdot(&dn, sa.s, sa.len); return 0; }
static void rr_addloq(const char type[2],const char *d, uint32 loc, uint32 mid,uint32 uid) { #ifdef USE_LOCMAPS char map[8]; dbger("-addloq: %s,%u (%u),%u,%u",d,loc,NOMATCH_HASH,uid,mid); if (loc != NOMATCH_HASH) return; dbger("NOMATCH hash found, adding loq records for %s",d); /* if (byte_equal(type,2,DNS_T_A)) { dbger("lookup LOQ for A record %s",fqdn_read(out,d)); } dbger("+addloq %s,%u,%u",fqdn_read(out,d),mid,uid); */ if (!stralloc_copyb(&key,"\0?",2)) nomem(); if (!stralloc_catb(&key,type,2)) nomem(); if (!stralloc_catb(&key,d,dns_domain_length(d))) nomem(); uint32_pack(map,mid); uint32_pack(map+4,uid); cdb_make_add(&cdb,key.s,key.len,map,8); #endif return; }
static int doit(char *q,char qtype[2]) { unsigned int bpos; unsigned int anpos; unsigned int aupos; unsigned int arpos; char *control; char *wild; int flaggavesoa; int flagfound; int r; int flagns; int flagauthoritative; char x[20]; uint16 u16; char addr[8][4]; int addrnum; uint32 addrttl; int i; anpos = response_len; control = q; for (;;) { flagns = 0; flagauthoritative = 0; cdb_findstart(&c); while (r = find(control,0)) { if (r == -1) return 0; if (byte_equal(type,2,DNS_T_SOA)) flagauthoritative = 1; if (byte_equal(type,2,DNS_T_NS)) flagns = 1; } if (flagns) break; if (!*control) return 0; /* q is not within our bailiwick */ control += *control; control += 1; } if (!flagauthoritative) { response[2] &= ~4; goto AUTHORITY; /* q is in a child zone */ } flaggavesoa = 0; flagfound = 0; wild = q; for (;;) { addrnum = 0; addrttl = 0; cdb_findstart(&c); while (r = find(wild,wild != q)) { if (r == -1) return 0; flagfound = 1; if (flaggavesoa && byte_equal(type,2,DNS_T_SOA)) continue; if (byte_diff(type,2,qtype) && byte_diff(qtype,2,DNS_T_ANY) && byte_diff(type,2,DNS_T_CNAME)) continue; if (byte_equal(type,2,DNS_T_A) && (dlen - dpos == 4)) { addrttl = ttl; i = dns_random(addrnum + 1); if (i < 8) { if ((i < addrnum) && (addrnum < 8)) byte_copy(addr[addrnum],4,addr[i]); byte_copy(addr[i],4,data + dpos); } if (addrnum < 1000000) ++addrnum; continue; } if (!response_rstart(q,type,ttl)) return 0; if (byte_equal(type,2,DNS_T_NS) || byte_equal(type,2,DNS_T_CNAME) || byte_equal(type,2,DNS_T_PTR)) { if (!doname()) return 0; } else if (byte_equal(type,2,DNS_T_MX)) { if (!dobytes(2)) return 0; if (!doname()) return 0; } else if (byte_equal(type,2,DNS_T_SOA)) { if (!doname()) return 0; if (!doname()) return 0; if (!dobytes(20)) return 0; flaggavesoa = 1; } else if (!response_addbytes(data + dpos,dlen - dpos)) return 0; response_rfinish(RESPONSE_ANSWER); } for (i = 0;i < addrnum;++i) if (i < 8) { if (!response_rstart(q,DNS_T_A,addrttl)) return 0; if (!response_addbytes(addr[i],4)) return 0; response_rfinish(RESPONSE_ANSWER); } if (flagfound) break; if (wild == control) break; if (!*wild) break; /* impossible */ wild += *wild; wild += 1; } if (!flagfound) response_nxdomain(); AUTHORITY: aupos = response_len; if (flagauthoritative && (aupos == anpos)) { cdb_findstart(&c); while (r = find(control,0)) { if (r == -1) return 0; if (byte_equal(type,2,DNS_T_SOA)) { if (!response_rstart(control,DNS_T_SOA,ttl)) return 0; if (!doname()) return 0; if (!doname()) return 0; if (!dobytes(20)) return 0; response_rfinish(RESPONSE_AUTHORITY); break; } } } else if (want(control,DNS_T_NS)) { cdb_findstart(&c); while (r = find(control,0)) { if (r == -1) return 0; if (byte_equal(type,2,DNS_T_NS)) { if (!response_rstart(control,DNS_T_NS,ttl)) return 0; if (!doname()) return 0; response_rfinish(RESPONSE_AUTHORITY); } } } arpos = response_len; bpos = anpos; while (bpos < arpos) { bpos = dns_packet_skipname(response,arpos,bpos); if (!bpos) return 0; bpos = dns_packet_copy(response,arpos,bpos,x,10); if (!bpos) return 0; if (byte_equal(x,2,DNS_T_NS) || byte_equal(x,2,DNS_T_MX)) { if (byte_equal(x,2,DNS_T_NS)) { if (!dns_packet_getname(response,arpos,bpos,&d1)) return 0; } else if (!dns_packet_getname(response,arpos,bpos + 2,&d1)) return 0; case_lowerb(d1,dns_domain_length(d1)); if (want(d1,DNS_T_A)) { cdb_findstart(&c); while (r = find(d1,0)) { if (r == -1) return 0; if (byte_equal(type,2,DNS_T_A)) { if (!response_rstart(d1,DNS_T_A,ttl)) return 0; if (!dobytes(4)) return 0; response_rfinish(RESPONSE_ADDITIONAL); } } } } uint16_unpack_big(x + 8,&u16); bpos += u16; } if (flagauthoritative && (response_len > 512)) { byte_zero(response + RESPONSE_ADDITIONAL,2); response_len = arpos; if (response_len > 512) { byte_zero(response + RESPONSE_AUTHORITY,2); response_len = aupos; } } return 1; }
main() { struct address t; int i; int j; int k; char ch; umask(022); if (!address_alloc_readyplus(&x,0)) nomem(); fd = open_read("data"); if (fd == -1) strerr_die2sys(111,FATAL,"unable to open data: "); buffer_init(&b,read,fd,bspace,sizeof bspace); fdcdb = open_trunc("data.tmp"); if (fdcdb == -1) die_datatmp(); if (cdb_make_start(&cdb,fdcdb) == -1) die_datatmp(); while (match) { ++linenum; if (getln(&b,&line,&match,'\n') == -1) strerr_die2sys(111,FATAL,"unable to read line: "); while (line.len) { ch = line.s[line.len - 1]; if ((ch != ' ') && (ch != '\t') && (ch != '\n')) break; --line.len; } if (!line.len) continue; j = 1; for (i = 0; i < NUMFIELDS; ++i) { if (j >= line.len) { if (!stralloc_copys(&f[i],"")) nomem(); } else { k = byte_chr(line.s + j,line.len - j,':'); if (!stralloc_copyb(&f[i],line.s + j,k)) nomem(); j += k + 1; } } switch(line.s[0]) { default: syntaxerror(": unrecognized leading character"); case '#': break; case '-': break; case '+': byte_zero(&t,sizeof t); if (!dns_domain_fromdot(&t.name,f[0].s,f[0].len)) nomem(); t.namelen = dns_domain_length(t.name); case_lowerb(t.name,t.namelen); if (!stralloc_0(&f[1])) nomem(); if (!ip4_scan(f[1].s,t.ip)) syntaxerror(": malformed IP address"); if (!stralloc_0(&f[2])) nomem(); if (!stralloc_0(&f[2])) nomem(); byte_copy(t.location,2,f[2].s); if (!address_alloc_append(&x,&t)) nomem(); break; case '%': if (!stralloc_0(&f[0])) nomem(); if (!stralloc_0(&f[0])) nomem(); if (!stralloc_copyb(&result,f[0].s,2)) nomem(); if (!stralloc_0(&f[1])) nomem(); if (!stralloc_copys(&key,"%")) nomem(); ipprefix_cat(&key,f[1].s); if (cdb_make_add(&cdb,key.s,key.len,result.s,result.len) == -1) die_datatmp(); break; } } close(fd); address_sort(x.s,x.len); i = 0; while (i < x.len) { for (j = i + 1; j < x.len; ++j) if (address_diff(x.s + i,x.s + j)) break; if (!stralloc_copys(&key,"+")) nomem(); if (!stralloc_catb(&key,x.s[i].location,2)) nomem(); if (!stralloc_catb(&key,x.s[i].name,x.s[i].namelen)) nomem(); if (!stralloc_copys(&result,"")) nomem(); while (i < j) if (!stralloc_catb(&result,x.s[i++].ip,4)) nomem(); if (cdb_make_add(&cdb,key.s,key.len,result.s,result.len) == -1) die_datatmp(); } if (cdb_make_finish(&cdb) == -1) die_datatmp(); if (fsync(fdcdb) == -1) die_datatmp(); if (close(fdcdb) == -1) die_datatmp(); /* NFS stupidity */ if (rename("data.tmp","data.cdb") == -1) strerr_die2sys(111,FATAL,"unable to move data.tmp to data.cdb: "); _exit(0); }
void rr_addname(const char *d) { rr_add(d,dns_domain_length(d)); }
int build (stralloc *sa, char *q, int flagsoa, char id[2]) { char ttl[4]; char ttd[8]; char type[2]; char misc[20]; char recordloc[2]; struct tai cutoff; unsigned int rdatapos = 0; dpos = 0; copy (type, 2); if (flagsoa) if (byte_diff (type, 2, DNS_T_SOA)) return 0; if (!flagsoa) if (byte_equal (type, 2, DNS_T_SOA)) return 0; if (!stralloc_copyb (sa, id, 2)) err (-1, "could not allocate enough memory"); if (!stralloc_catb (sa, "\204\000\0\0\0\1\0\0\0\0", 10)) err (-1, "could not allocate enough memory"); copy (misc, 1); if ((misc[0] == '=' + 1) || (misc[0] == '*' + 1)) { --misc[0]; copy (recordloc, 2); if (byte_diff (recordloc, 2, clientloc)) return 0; } if (misc[0] == '*') { if (flagsoa) return 0; if (!stralloc_catb (sa, "\1*", 2)) err (-1, "could not allocate enough memory"); } if (!stralloc_catb (sa, q, dns_domain_length (q))) err (-1, "could not allocate enough memory"); if (!stralloc_catb (sa, type, 2)) err (-1, "could not allocate enough memory"); copy (ttl, 4); copy (ttd, 8); if (byte_diff (ttd, 8, "\0\0\0\0\0\0\0\0")) { tai_unpack (ttd, &cutoff); if (byte_equal (ttl, 4, "\0\0\0\0")) { if (tai_less (&cutoff, &now)) return 0; uint32_pack_big (ttl, 2); } else if (!tai_less (&cutoff, &now)) return 0; } if (!stralloc_catb (sa, DNS_C_IN, 2)) err (-1, "could not allocate enough memory"); if (!stralloc_catb (sa, ttl, 4)) err (-1, "could not allocate enough memory"); if (!stralloc_catb(sa,"\0\0",2)) err (-1, "could not allocate enough memory"); rdatapos = sa->len; if (byte_equal (type, 2, DNS_T_SOA)) { doname (sa); doname (sa); copy (misc, 20); if (!stralloc_catb (sa, misc, 20)) err (-1, "could not allocate enough memory"); } else if (byte_equal (type, 2, DNS_T_NS) || byte_equal (type, 2, DNS_T_PTR) || byte_equal (type, 2, DNS_T_CNAME)) { doname (sa); } else if (byte_equal (type, 2, DNS_T_MX)) { copy (misc, 2); if (!stralloc_catb (sa, misc, 2)) err (-1, "could not allocate enough memory"); doname (sa); } else { if (!stralloc_catb (sa, data + dpos, dlen - dpos)) err (-1, "could not allocate enough memory"); } if (sa->len > 65535) errx (-1, "could not read from file `data.cdb': format error"); uint16_pack_big (sa->s + rdatapos - 2, sa->len - rdatapos); return 1; }
int main (int argc, char *argv[]) { int n = 0; time_t t = 0; struct sigaction sa; char qtype[2]; char qclass[2]; char header[12]; const char *x = NULL; unsigned int pos = 0; unsigned long long qnum = 0; sa.sa_handler = handle_term; sigaction (SIGINT, &sa, NULL); sigaction (SIGTERM, &sa, NULL); sa.sa_handler = SIG_IGN; sigaction (SIGPIPE, &sa, NULL); prog = strdup ((x = strrchr (argv[0], '/')) != NULL ? x + 1 : argv[0]); n = check_option (argc, argv); argc -= n; argv += n; if (mode & DAEMON) /* redirect stderr to a log file */ redirect_to_log (logfile, STDERR_FILENO); time (&t); memset (seed, 0, sizeof (seed)); strftime (seed, sizeof (seed), "%b-%d %Y %T %Z", localtime (&t)); warnx ("version %s: starting %s\n", VERSION, seed); set_timezone (); if (debug_level) warnx ("TIMEZONE: %s", env_get ("TZ")); read_conf (cfgfile); if (!debug_level) if ((x = env_get ("DEBUG_LEVEL"))) debug_level = atol (x); warnx ("DEBUG_LEVEL set to `%d'", debug_level); dns_random_init (seed); axfr = env_get ("AXFR"); if (debug_level) warnx ("AXFR set to `%s'", axfr); x = env_get ("TCPREMOTEIP"); if (debug_level) warnx ("TCPREMOTEIP set to `%s'", x); if (x) ip4_scan (x, ip); else byte_zero (ip, 4); x = env_get ("TCPREMOTEPORT"); if (debug_level) warnx ("TCPREMOTEPORT set to `%s'", x); if (!x) x = "0"; scan_ulong (x, &port); droproot (); for (;;) { netread (tcpheader, 2); uint16_unpack_big (tcpheader, &len); if (len > 512) errx (-1, "excessively large request"); netread (buf, len); pos = dns_packet_copy (buf, len, 0, header, 12); if (!pos) errx (-1, "truncated request"); if (header[2] & 254) errx (-1, "bogus query"); if (header[4] || (header[5] != 1)) errx (-1, "bogus query"); pos = dns_packet_getname (buf, len, pos, &zone); if (!pos) errx (-1, "truncated request"); zonelen = dns_domain_length (zone); pos = dns_packet_copy (buf, len, pos, qtype, 2); if (!pos) errx (-1, "truncated request"); pos = dns_packet_copy (buf, len, pos, qclass, 2); if (!pos) errx (-1, "truncated request"); if (byte_diff(qclass, 2, DNS_C_IN) && byte_diff(qclass, 2, DNS_C_ANY)) errx (-1, "bogus query: bad class"); log_query (++qnum, ip, port, header, zone, qtype); if (byte_equal(qtype,2,DNS_T_AXFR)) { case_lowerb (zone, zonelen); fdcdb = open_read ("data.cdb"); if (fdcdb == -1) errx (-1, "could not read from file `data.cdb'"); doaxfr (header); close (fdcdb); } else { if (!response_query (zone, qtype, qclass)) err (-1, "could not allocate enough memory"); response[2] |= 4; case_lowerb (zone, zonelen); response_id (header); response[3] &= ~128; if (!(header[2] & 1)) response[2] &= ~1; if (!respond (zone, qtype, ip)) errx (-1, "could not find information in file `data.cdb'"); print (response, response_len); } } }
int main() { unsigned int pos; char header[12]; char qtype[2]; char qclass[2]; const char *x; droproot(FATAL); dns_random_init(seed); axfr = env_get("AXFR"); x = env_get("TCPREMOTEIP"); if (x && ip6_scan(x,ip)) ; else byte_zero(ip,16); x = env_get("TCPREMOTEPORT"); if (!x) x = "0"; scan_ulong(x,&port); for (;;) { netread(tcpheader,2); uint16_unpack_big(tcpheader,&len); if (len > 512) strerr_die2x(111,FATAL,"excessively large request"); netread(buf,len); pos = dns_packet_copy(buf,len,0,header,12); if (!pos) die_truncated(); if (header[2] & 254) strerr_die2x(111,FATAL,"bogus query"); if (header[4] || (header[5] != 1)) strerr_die2x(111,FATAL,"bogus query"); pos = dns_packet_getname(buf,len,pos,&zone); if (!pos) die_truncated(); zonelen = dns_domain_length(zone); pos = dns_packet_copy(buf,len,pos,qtype,2); if (!pos) die_truncated(); pos = dns_packet_copy(buf,len,pos,qclass,2); if (!pos) die_truncated(); if (byte_diff(qclass,2,DNS_C_IN) && byte_diff(qclass,2,DNS_C_ANY)) strerr_die2x(111,FATAL,"bogus query: bad class"); pos = check_edns0(header, buf, len, pos); if (!pos) die_truncated(); qlog(ip,port,header,zone,qtype," "); if (byte_equal(qtype,2,DNS_T_AXFR)) { case_lowerb(zone,zonelen); fdcdb = open_read("data.cdb"); if (fdcdb == -1) die_cdbread(); doaxfr(header); close(fdcdb); } else { if (!response_query(zone,qtype,qclass)) nomem(); response[2] |= 4; case_lowerb(zone,zonelen); response_id(header); response[3] &= ~128; if (!(header[2] & 1)) response[2] &= ~1; if (!respond(zone,qtype,ip)) die_outside(); print(response,response_len); } } }