named-xfer.c

早期freebsd实现

				syslog(LOG_ERR, "malloc(%u) failed",
				    2 * PACKETSZ);
				error++;
				break;
			}
			bufsize = 2 * PACKETSZ;
		}
		bzero((char *)&sin, sizeof(sin));
		sin.sin_family = AF_INET;
		sin.sin_port = port;
		sin.sin_addr = zp->z_addr[cnt];
		if ((s = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
			syslog(LOG_ERR, "socket: %m");
			error++;
			break;
		}	
		dprintf(2, (ddt, "connecting to server #%d [%s].%d\n",
			    cnt+1, inet_ntoa(sin.sin_addr),
			    ntohs(sin.sin_port)));
		if (connect(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
			(void) my_close(s);
			error++;
			dprintf(2, (ddt, "connect failed: %s\n",
				    strerror(errno)));
			continue;
		}	
tryagain:
		if ((n = res_mkquery(QUERY, zp->z_origin, Class,
		    T_SOA, (char *)NULL, 0, NULL, (char *)buf, bufsize)) < 0) {
			if (!quiet)
			    syslog(LOG_ERR,
				   "zone %s: res_mkquery T_SOA failed",
				   zp->z_origin);
			(void) my_close(s);
#ifdef POSIX_SIGNALS
			(void) sigaction(SIGALRM, &osv, (struct sigaction *)0);
#else
			(void) sigvec(SIGALRM, &osv, (struct sigvec *)0);
#endif
			return XFER_FAIL;
		}
		/*
		 * Send length & message for SOA query
		 */
		if (writemsg(s, buf, n) < 0) {
			(void) my_close(s);
			error++;
			dprintf(2, (ddt, "writemsg failed\n"));
			continue;	
		}
		/*
		 * Get out your butterfly net and catch the SOA
		 */
		cp = buf;
		l = sizeof(u_int16_t);
		read_interrupted = 0;
		while (l > 0) {
			dprintf(11, (ddt, "Before setitimer\n"));
			(void) setitimer(ITIMER_REAL, &ival,
			    (struct itimerval *)NULL);
			dprintf(11, (ddt, "Before recv(l = %d)\n",n));
			errno = 0;
			if ((n = recv(s, (char *)cp, l, 0)) > 0) {
				cp += n;
				l -= n;
			} else {
				dprintf(11, (ddt,
				"bad recv->%d, errno= %d, read_interrupt=%d\n",
					     n, errno, read_interrupted));
				if (n == -1 && errno == EINTR 
				    && !read_interrupted)
					continue;
				error++;
				break;
			}
		}

		(void) setitimer(ITIMER_REAL, &zeroival,
		    (struct itimerval *)NULL);
		if (error) {
			(void) my_close(s);
			continue;
		}
		if ((len = htons(*(u_int16_t *)buf)) == 0) {
			(void) my_close(s);
			continue;
		}
		if (len > bufsize) {
			if ((buf = (u_char *)realloc(buf, len)) == NULL) {
				syslog(LOG_ERR,
		       "malloc(%u) failed for SOA from server [%s], zone %s\n",
				       len,
				       inet_ntoa(sin.sin_addr),
				       zp->z_origin);
				(void) my_close(s);
				continue;
			}
			bufsize = len;
		}
		l = len;
		cp = buf;
		while (l > 0) {
			(void) setitimer(ITIMER_REAL, &ival,
			    (struct itimerval *)NULL);
			errno = 0;
			if ((n = recv(s, (char *)cp, l, 0)) > 0) {
				cp += n;
				l -= n;
			} else {
				if (errno == EINTR && !read_interrupted)
					continue;
				error++;
				dprintf(11, (ddt,
					    "recv failed: n= %d, errno = %d\n",
					     n, errno));
				break;
			}
		}
		(void) setitimer(ITIMER_REAL, &zeroival,
				 (struct itimerval *)NULL);
		if (error) {
			(void) my_close(s);
			continue;
		}
#ifdef DEBUG
		if (debug >= 3) {
			(void)fprintf(ddt,"len = %d\n", len);
			fp_query((char *)buf, ddt);
		}
#endif
		hp = (HEADER *) buf;
		ancount = ntohs(hp->ancount);
		aucount = ntohs(hp->nscount);

		/*
		 * close socket if:
		 *  1) rcode != NOERROR
		 *  2) not an authority response
		 *  3) both the number of answers and authority count < 1)
		 */
		if (hp->rcode != NOERROR || !(hp->aa) || 
		    (ancount < 1 && aucount < 1)) {
#ifndef GEN_AXFR

			if (Class == C_IN) {
				dprintf(1, (ddt,"SOA failed, trying C_HS\n"));
				Class = C_HS;
				goto tryagain;
			}
#endif
			if (!quiet)
				syslog(LOG_ERR,
	    "%s from [%s], zone %s: rcode %d, aa %d, ancount %d, aucount %d\n",
				    "bad response to SOA query",
				    inet_ntoa(sin.sin_addr), zp->z_origin,
				    hp->rcode, hp->aa, ancount, aucount);
			dprintf(1, (ddt,
	    "%s from [%s], zone %s: rcode %d, aa %d, ancount %d, aucount %d\n",
				    "bad response to SOA query",
				    inet_ntoa(sin.sin_addr), zp->z_origin,
				    hp->rcode, hp->aa, ancount, aucount));
			(void) my_close(s);
			error++;
			continue;
		}
		zp_start = *zp;
		if (len < sizeof(HEADER) + QFIXEDSZ) {
	badsoa:
			if (!quiet)
				syslog(LOG_ERR,
				 "malformed SOA from [%s], zone %s: too short\n",
				       inet_ntoa(sin.sin_addr), zp->z_origin);
			dprintf(1, (ddt,
				    "malformed SOA from [%s]: too short\n",
				    inet_ntoa(sin.sin_addr)));
			(void) my_close(s);
			error++;
			continue;
		}
		tmp = buf + sizeof(HEADER);
		eom = buf + len;
		if ((n = dn_skipname(tmp, eom)) == -1)
			goto badsoa;
		tmp += n + QFIXEDSZ;
		if ((n = dn_skipname(tmp, eom)) == -1)
			goto badsoa;
		tmp += n;
		if (soa_zinfo(&zp_start, tmp, eom) == -1)
			goto badsoa;
		/* compare using sequence space arithmetic */
		if (SEQ_GT(zp_start.z_serial, serial_no) || serial_no == 0) {
			dprintf(1, (ddt, "need update, serial %d\n",
				    zp_start.z_serial));
			hp = (HEADER *) buf;
			soacnt = 0;
			nscnt = 0;
			for (;;) {
				if ((soacnt == 0) || (zp->z_type == Z_STUB)) {
					int type;
#ifdef	STUBS
					if (zp->z_type == Z_STUB) {
						if (!soacnt)
							type = T_SOA;
						else if (!nscnt)
							type = T_NS;
						else 
							type = T_SOA;
					} else
#endif
						type = T_AXFR;
					if ((n = res_mkquery(QUERY,
							     zp->z_origin,
							     Class,
							     type,
							     (char *)NULL,
							     0,
							     NULL,
							     (char *)buf,
							     bufsize
							     )) < 0) {
						if (!quiet) {
#ifdef STUBS
						    if (zp->z_type == Z_STUB)
							syslog(LOG_ERR,
							       (type == T_SOA)
					? "zone %s: res_mkquery T_SOA failed"
					: "zone %s: res_mkquery T_NS failed",
							       zp->z_origin);
						    else
#endif
							syslog(LOG_ERR,
					  "zone %s: res_mkquery T_AXFR failed",
							       zp->z_origin);
						}
						(void) my_close(s);
#ifdef POSIX_SIGNALS
						sigaction(SIGALRM, &osv,
							(struct sigaction *)0);
#else
						sigvec(SIGALRM, &osv,
						       (struct sigvec *)0);
#endif
						return XFER_FAIL;
					}
					/*
					 * Send length & msg for zone transfer
					 */
					if (writemsg(s, buf, n) < 0) {
						(void) my_close(s);
						error++;
						dprintf(2, (ddt,
							    "writemsg failed\n"
							    ));
						break;	
					}
				}
				/*
				 * Receive length & response
				 */
				cp = buf;
				l = sizeof(u_int16_t);
				/* allow extra time for fork on first read */
				if (soacnt == 0)
					ival.it_value.tv_sec = 300;
				while (l > 0) {
					(void) setitimer(ITIMER_REAL, &ival,
							 (struct itimerval *)
							     NULL
							 );
					errno = 0;
					n = recv(s, (char *)cp, l, 0);
					if (n > 0) {
						cp += n;
						l -= n;
					} else {
						if (errno == EINTR
						    && !read_interrupted)
							continue;
						error++;
						dprintf(2, (ddt,
					    "recv failed: n= %d, errno = %d\n",
							    n, errno));
						break;
					}
				}
				if (soacnt == 0)
					ival.it_value.tv_sec = XFER_TIMER;
				(void) setitimer(ITIMER_REAL, &zeroival,
						 (struct itimerval *)NULL);
				if (error)
					break;
				if ((len = htons(*(u_int16_t *)buf)) == 0)
					break;
				l = len;
				cp = buf;
				eom = buf + len;
				while (l > 0) {
					(void) setitimer(ITIMER_REAL, &ival,
							 (struct itimerval *)
							     NULL
							 );
					errno = 0;
					n = recv(s, (char *)cp, l, 0);
					if (n > 0) {
						cp += n;
						l -= n;
					} else {
						if (errno == EINTR
						    && !read_interrupted)
							continue;
						error++;
						dprintf(2, (ddt,
							    "recv failed\n"));
						break;
					}
				}
				(void) setitimer(ITIMER_REAL, &zeroival,
						 (struct itimerval *)NULL);
				if (error)
					break;
#ifdef DEBUG
				if (debug >= 3) {
					(void)fprintf(ddt,"len = %d\n", len);
					fp_query((char *)buf, ddt);
				}
				if (fp)
					fp_query((char *)buf, fp);
#endif
				if (len < sizeof(HEADER)) {
		badrec:
					error++;
					if (!quiet)
						syslog(LOG_ERR,
				       "record too short from [%s], zone %s\n",
						       inet_ntoa(sin.sin_addr),
						       zp->z_source);
					dprintf(1, (ddt,
						"record too short from [%s]\n",
						    inet_ntoa(sin.sin_addr)));
					break;
				}
				cp = buf + sizeof(HEADER);
				if (hp->qdcount) {
					if ((n = dn_skipname(cp, eom)) == -1
					    || n + QFIXEDSZ >= eom - cp)
						goto badrec;
					cp += n + QFIXEDSZ;
				}
				nmp = cp;
				if ((n = dn_skipname(cp, eom)) == -1)
					goto badrec;
				tmp = cp + n;
#ifdef STUBS
			if (zp->z_type == Z_STUB) {
				ancount = ntohs(hp->ancount);
				for (cnt = 0 ; cnt < ancount ; cnt++) {

					n = print_output(buf, bufsize, cp);
					cp += n;
				}
				if (hp->nscount) {
					/* we should not get here */
					ancount = ntohs(hp->nscount);
					for (cnt = 0 ; cnt < ancount ; cnt++) {
					    n = print_output(buf, bufsize, cp);
						cp += n;
					}
				}
				ancount = ntohs(hp->arcount);
				for (cnt = 0 ; cnt < ancount ; cnt ++) {
					n = print_output(buf, bufsize, cp);
					cp += n;
				}
				if (cp != eom) {
					dprintf(1, (ddt,
				     "getzone: print_update failed (%d, %d)\n",
						cp - buf, n));
					error++;
					break;
				}
		
			} else {
#endif /*STUBS*/
				n = print_output(buf, bufsize, cp);
				if (cp + n != eom) {
					dprintf(1, (ddt,
				     "getzone: print_update failed (%d, %d)\n",
					    cp - buf, n));
					error++;
					break;
				}
#ifdef STUBS
			}
#endif
			GETSHORT(n, tmp);
			if (n == T_SOA) {
				if (soacnt == 0) {
					soacnt++;
					if (dn_expand(buf, buf + 512, nmp,
					    name, sizeof(name)) == -1)
						goto badsoa;
					if (eom - tmp
					    <= 2 * sizeof(u_int16_t)
					       + sizeof(u_int32_t)) {
						goto badsoa;
					}
					tmp += 2 * sizeof(u_int16_t)
					       + sizeof(u_int32_t);
					if ((n = dn_skipname(tmp, eom)) == -1)
						goto badsoa;
					tmp += n;
					if ((n = dn_skipname(tmp, eom)) == -1)
						goto badsoa;
					tmp += n;
					if (eom - tmp <= sizeof(u_int32_t))
						goto badsoa;
					GETLONG(serial, tmp);
					dprintf(3, (ddt,
					       "first SOA for %s, serial %d\n",
						    name, serial));
					continue;
				}
				if (dn_expand(buf, buf + 512, nmp, name2, 
				    sizeof(name2)) == -1)
					goto badsoa;
				if (strcasecmp((char *)name,
					       (char *)name2) != 0) {
					dprintf(2, (ddt,
						    "extraneous SOA for %s\n",
						    name2));
					continue;
				}
				tmp -= sizeof(u_int16_t);
				if (soa_zinfo(&zp_finish, tmp, eom) == -1)
					goto badsoa;
				dprintf(2, (ddt,
					    "SOA, serial %d\n",
					    zp_finish.z_serial));
				if (serial != zp_finish.z_serial) {
					soacnt = 0;
					got_soa = 0;
					minimum_ttl = 0;
					strcpy(prev_origin, zp->z_origin);
					prev_dname[0] = DEF_DNAME;
					dprintf(1, (ddt,
						    "serial changed, restart\n"
						    ));
					/*
					 * Flush buffer, truncate file
					 * and seek to beginning to restart.
					 */
					fflush(dbfp);
					if (ftruncate(fileno(dbfp), 0) != 0) {
						if (!quiet)
						    syslog(LOG_ERR,
							"ftruncate %s: %m\n",
							tmpname);
						return(XFER_FAIL);
					}
					fseek(dbfp, 0L, 0);
				} else
					break;
#ifdef STUBS
			} else if (zp->z_type == Z_STUB && n == T_NS) {
				nscnt++;
			} else if (zp->z_type == Z_STUB) {
				break;
#endif
			}
		}
		(void) my_close(s);
		if (error == 0) {
#ifdef POSIX_SIGNALS
			(void) sigaction(SIGALRM, &osv,
					 (struct sigaction *)0);
#else
			(void) sigvec(SIGALRM, &osv, (struct sigvec *)0);
#endif
			return XFER_SUCCESS;
		}
		dprintf(2, (ddt, "error receiving zone transfer\n"));
	    } else if (zp_start.z_serial == serial_no) {
		(void) my_close(s);
		dprintf(1, (ddt,
			    "zone up-to-date, serial %u\n",
			    zp_start.z_serial));
		return XFER_UPTODATE;
	    } else {
		(void) my_close(s);
		if (!quiet)
		    syslog(LOG_ERR,
		      "serial from [%s], zone %s: %u lower than current: %u\n",
			   inet_ntoa(sin.sin_addr), zp->z_origin,
			   zp_start.z_serial, serial_no);
		dprintf(1, (ddt,