static int dnsDecodeReply(char *buf, int offset, int n, int *id_return, AtomPtr *name_return, AtomPtr *value_return, int *af_return, unsigned *ttl_return) { int i = offset, j, m; int id = -1, b23, qdcount, ancount, nscount, arcount, rdlength; int class, type; unsigned int ttl; char b[2048]; int af = -1; AtomPtr name = NULL, value; char addresses[1024]; int addr_index = 0; int error = EDNS_NO_ADDRESS; unsigned final_ttl = 7 * 24 * 3600; int dnserror; if(n - i < 12) { error = EDNS_INVALID; goto fail; } DO_NTOHS(id, &buf[i]); i += 2; DO_NTOHS(b23, &buf[i]); i += 2; DO_NTOHS(qdcount, &buf[i]); i += 2; DO_NTOHS(ancount, &buf[i]); i += 2; DO_NTOHS(nscount, &buf[i]); i += 2; DO_NTOHS(arcount, &buf[i]); i += 2; do_log(D_DNS, "DNS id %d, b23 0x%x, qdcount %d, ancount %d, " "nscount %d, arcount %d\n", id, b23, qdcount, ancount, nscount, arcount); if((b23 & (0xF870)) != 0x8000) { do_log(L_ERROR, "Incorrect DNS reply (b23 = 0x%x).\n", b23); error = EDNS_INVALID; goto fail; } dnserror = b23 & 0xF; if(b23 & 0x200) { do_log(L_WARN, "Truncated DNS reply (b23 = 0x%x).\n", b23); } if(dnserror || qdcount != 1) { if(!dnserror) do_log(L_ERROR, "Unexpected number %d of DNS questions.\n", qdcount); if(dnserror == 1) error = EDNS_FORMAT; else if(dnserror == 2) error = EDNS_NO_RECOVERY; else if(dnserror == 3) error = EDNS_HOST_NOT_FOUND; else if(dnserror == 4 || dnserror == 5) error = EDNS_REFUSED; else if(dnserror == 0) error = EDNS_INVALID; else error = EUNKNOWN; goto fail; } /* We do this early, so that we can return the address family to the caller in case of error. */ i = labelsToString(buf, i, n, b, 2048, &m); if(i < 0) { error = EDNS_FORMAT; goto fail; } DO_NTOHS(type, &buf[i]); i += 2; DO_NTOHS(class, &buf[i]); i += 2; if(type == 1) af = 4; else if(type == 28) af = 6; else { error = EDNS_FORMAT; goto fail; } do_log(D_DNS, "DNS q: "); do_log_n(D_DNS, b, m); do_log(D_DNS, " (%d, %d)\n", type, class); name = internAtomLowerN(b, m); if(name == NULL) { error = ENOMEM; goto fail; } if(class != 1) { error = EDNS_FORMAT; goto fail; } #define PARSE_ANSWER(kind, label) \ do { \ i = labelsToString(buf, i, 1024, b, 2048, &m); \ if(i < 0) goto label; \ DO_NTOHS(type, &buf[i]); i += 2; if(i > 1024) goto label; \ DO_NTOHS(class, &buf[i]); i += 2; if(i > 1024) goto label; \ DO_NTOHL(ttl, &buf[i]); i += 4; if(i > 1024) goto label; \ DO_NTOHS(rdlength, &buf[i]); i += 2; if(i > 1024) goto label; \ do_log(D_DNS, "DNS " kind ": "); \ do_log_n(D_DNS, b, m); \ do_log(D_DNS, " (%d, %d): %d bytes, ttl %u\n", \ type, class, rdlength, ttl); \ } while(0) for(j = 0; j < ancount; j++) { PARSE_ANSWER("an", fail); if(strcasecmp_n(name->string, b, m) == 0) { if(class != 1) { do_log(D_DNS, "DNS: %s: unknown class %d.\n", name->string, class); error = EDNS_UNSUPPORTED; goto cont; } if(type == 1 || type == 28) { if((type == 1 && rdlength != 4) || (type == 28 && rdlength != 16)) { do_log(L_ERROR, "DNS: %s: unexpected length %d of %s record.\n", scrub(name->string), rdlength, type == 1 ? "A" : "AAAA"); error = EDNS_INVALID; if(rdlength <= 0 || rdlength >= 32) goto fail; goto cont; } if(af == 0) { do_log(L_WARN, "DNS: %s: host has both A and CNAME -- " "ignoring CNAME.\n", scrub(name->string)); addr_index = 0; af = -1; } if(type == 1) { if(af < 0) af = 4; else if(af == 6) { do_log(L_WARN, "Unexpected AAAA reply.\n"); goto cont; } } else { if(af < 0) af = 6; else if(af == 4) { do_log(L_WARN, "Unexpected A reply.\n"); goto cont; } } if(addr_index == 0) { addresses[0] = DNS_A; addr_index++; } else { if(addr_index > 1000) { error = EDNS_INVALID; goto fail; } } assert(addresses[0] == DNS_A); if(final_ttl > ttl) final_ttl = ttl; memset(&addresses[addr_index], 0, sizeof(HostAddressRec)); if(type == 1) { addresses[addr_index] = 4; memcpy(addresses + addr_index + 1, buf + i, 4); } else { addresses[addr_index] = 6; memcpy(addresses + addr_index + 1, buf + i, 16); } addr_index += sizeof(HostAddressRec); } else if(type == 5) { int j, k; if(af != 0 && addr_index > 0) { do_log(L_WARN, "DNS: host has both CNAME and A -- " "ignoring CNAME.\n"); goto cont; } af = 0; if(addr_index != 0) { /* Only warn if the CNAMEs are not identical */ char tmp[512]; int jj, kk; assert(addresses[0] == DNS_CNAME); jj = labelsToString(buf, i, n, tmp, 512, &kk); if(jj < 0 || kk != strlen(addresses + 1) || memcmp(addresses + 1, tmp, kk) != 0) { do_log(L_WARN, "DNS: " "%s: host has multiple CNAMEs -- " "ignoring subsequent.\n", scrub(name->string)); } goto cont; } addresses[0] = DNS_CNAME; addr_index++; j = labelsToString(buf, i, n, addresses + 1, 1020, &k); if(j < 0) { addr_index = 0; error = ENAMETOOLONG; continue; } addr_index = k + 1; } else { error = EDNS_NO_ADDRESS; i += rdlength; continue; } } cont: i += rdlength; } #if (LOGGING_MAX & D_DNS) for(j = 0; j < nscount; j++) { PARSE_ANSWER("ns", nofail); i += rdlength; } for(j = 0; j < arcount; j++) { PARSE_ANSWER("ar", nofail); i += rdlength; } nofail: #endif #undef PARSE_ANSWER do_log(D_DNS, "DNS: %d bytes\n", addr_index); if(af < 0) goto fail; value = internAtomN(addresses, addr_index); if(value == NULL) { error = ENOMEM; goto fail; } assert(af >= 0); *id_return = id; *name_return = name; *value_return = value; *af_return = af; *ttl_return = final_ttl; return 1; fail: *id_return = id; *name_return = name; *value_return = NULL; *af_return = af; return -error; }
int parseConfigLine(char *line, char *filename, int lineno, int set) { int x0, x1; int i, from, to; AtomPtr name, value; ConfigVariablePtr var; int iv; float fv; AtomPtr av; AtomListPtr alv; IntListPtr ilv; i = skipWhitespace(line, 0); if(line[i] == '\n' || line[i] == '\0' || line[i] == '#') return 0; x0 = i; while(letter(line[i]) || digit(line[i])) i++; x1 = i; i = skipWhitespace(line, i); if(line[i] != '=') { goto syntax; } i++; i = skipWhitespace(line, i); name = internAtomN(line + x0, x1 - x0); var = findConfigVariable(name); releaseAtom(name); if(set && var->setter == NULL) return -2; if(var == NULL) { if(!set) { do_log(L_ERROR, "%s:%d: unknown config variable ", filename, lineno); do_log_n(L_ERROR, line + x0, x1 - x0); do_log(L_ERROR, "\n"); } return -1; } i = skipWhitespace(line, i); switch(var->type) { case CONFIG_INT: case CONFIG_OCTAL: case CONFIG_HEX: i = parseInt(line, i, &iv); if(i < 0) goto syntax; if(set) var->setter(var, &iv); else *var->value.i = iv; break; case CONFIG_TIME: i = parseTime(line, i, &iv); if(i < 0) goto syntax; i = skipWhitespace(line, i); if(line[i] != '\n' && line[i] != '\0' && line[i] != '#') goto syntax; if(set) var->setter(var, &iv); else *var->value.i = iv; break; case CONFIG_BOOLEAN: case CONFIG_TRISTATE: case CONFIG_TETRASTATE: case CONFIG_PENTASTATE: iv = parseState(line, i, var->type); if(iv < 0) goto syntax; if(set) var->setter(var, &iv); else *var->value.i = iv; break; case CONFIG_FLOAT: if(!digit(line[i]) && line[i] != '.') goto syntax; fv = atof(line + i); if(set) var->setter(var, &fv); else *var->value.f = fv; break; case CONFIG_ATOM: case CONFIG_ATOM_LOWER: case CONFIG_PASSWORD: i = parseAtom(line, i, &av, (var->type == CONFIG_ATOM_LOWER)); if(i < 0) goto syntax; if(!av) { if(!set) do_log(L_ERROR, "%s:%d: couldn't allocate atom.\n", filename, lineno); return -1; } i = skipWhitespace(line, i); if(line[i] != '\n' && line[i] != '\0' && line[i] != '#') { releaseAtom(av); goto syntax; } if(set) var->setter(var, &av); else { if(*var->value.a) releaseAtom(*var->value.a); *var->value.a = av; } break; case CONFIG_INT_LIST: ilv = makeIntList(0); if(ilv == NULL) { if(!set) do_log(L_ERROR, "%s:%d: couldn't allocate int list.\n", filename, lineno); return -1; } while(1) { i = parseInt(line, i, &from); if(i < 0) goto syntax; to = from; i = skipWhitespace(line, i); if(line[i] == '-') { i = skipWhitespace(line, i + 1); i = parseInt(line, i, &to); if(i < 0) { destroyIntList(ilv); goto syntax; } i = skipWhitespace(line, i); } intListCons(from, to, ilv); if(line[i] == '\n' || line[i] == '\0' || line[i] == '#') break; if(line[i] != ',') { destroyIntList(ilv); goto syntax; } i = skipWhitespace(line, i + 1); } if(set) var->setter(var, &ilv); else { if(*var->value.il) destroyIntList(*var->value.il); *var->value.il = ilv; } break; case CONFIG_ATOM_LIST: case CONFIG_ATOM_LIST_LOWER: alv = makeAtomList(NULL, 0); if(alv == NULL) { if(!set) do_log(L_ERROR, "%s:%d: couldn't allocate atom list.\n", filename, lineno); return -1; } while(1) { i = parseAtom(line, i, &value, (var->type == CONFIG_ATOM_LIST_LOWER)); if(i < 0) goto syntax; if(!value) { if(!set) do_log(L_ERROR, "%s:%d: couldn't allocate atom.\n", filename, lineno); return -1; } atomListCons(value, alv); i = skipWhitespace(line, i); if(line[i] == '\n' || line[i] == '\0' || line[i] == '#') break; if(line[i] != ',') { destroyAtomList(alv); goto syntax; } i = skipWhitespace(line, i + 1); } if(set) var->setter(var, &alv); else { if(*var->value.al) destroyAtomList(*var->value.al); *var->value.al = alv; } break; default: abort(); } return 1; syntax: if(!set) do_log(L_ERROR, "%s:%d: parse error.\n", filename, lineno); return -1; }