diff --git a/Makefile.inc b/Makefile.inc index ec0cba4..81686a8 100644 --- a/Makefile.inc +++ b/Makefile.inc @@ -20,6 +20,7 @@ CSOURCES = ares__close_sockets.c \ ares_library_init.c \ ares_llist.c \ ares_mkquery.c \ + ares_create_query.c \ ares_nowarn.c \ ares_options.c \ ares_parse_a_reply.c \ @@ -92,6 +93,7 @@ MANPAGES = ares_cancel.3 \ ares_library_cleanup.3 \ ares_library_init.3 \ ares_mkquery.3 \ + ares_create_query.3 \ ares_parse_a_reply.3 \ ares_parse_aaaa_reply.3 \ ares_parse_mx_reply.3 \ @@ -133,6 +135,7 @@ HTMLPAGES = ares_cancel.html \ ares_library_cleanup.html \ ares_library_init.html \ ares_mkquery.html \ + ares_create_query.html \ ares_parse_a_reply.html \ ares_parse_aaaa_reply.html \ ares_parse_mx_reply.html \ @@ -173,6 +176,7 @@ PDFPAGES = ares_cancel.pdf \ ares_library_cleanup.pdf \ ares_library_init.pdf \ ares_mkquery.pdf \ + ares_create_query.pdf \ ares_parse_a_reply.pdf \ ares_parse_aaaa_reply.pdf \ ares_parse_mx_reply.pdf \ diff --git a/ares.h b/ares.h index c5e4069..f0cc824 100644 --- a/ares.h +++ b/ares.h @@ -143,6 +143,7 @@ extern "C" { #define ARES_FLAG_NOSEARCH (1 << 5) #define ARES_FLAG_NOALIASES (1 << 6) #define ARES_FLAG_NOCHECKRESP (1 << 7) +#define ARES_FLAG_EDNS (1 << 8) /* Option mask values */ #define ARES_OPT_FLAGS (1 << 0) @@ -160,6 +161,7 @@ extern "C" { #define ARES_OPT_SOCK_RCVBUF (1 << 12) #define ARES_OPT_TIMEOUTMS (1 << 13) #define ARES_OPT_ROTATE (1 << 14) +#define ARES_OPT_EDNSPSZ (1 << 15) /* Nameinfo flag values */ #define ARES_NI_NOFQDN (1 << 0) @@ -265,6 +267,7 @@ struct ares_options { void *sock_state_cb_data; struct apattern *sortlist; int nsort; + int ednspsz; }; struct hostent; @@ -403,6 +406,15 @@ CARES_EXTERN void ares_process_fd(ares_channel channel, ares_socket_t read_fd, ares_socket_t write_fd); +CARES_EXTERN int ares_create_query(const char *name, + int dnsclass, + int type, + unsigned short id, + int rd, + unsigned char **buf, + int *buflen, + int max_udp_size); + CARES_EXTERN int ares_mkquery(const char *name, int dnsclass, int type, diff --git a/ares_create_query.3 b/ares_create_query.3 new file mode 100644 index 0000000..d01b8d8 --- /dev/null +++ b/ares_create_query.3 @@ -0,0 +1,79 @@ +.\" +.\" Copyright 1998, 2000 by the Massachusetts Institute of Technology. +.\" +.\" Permission to use, copy, modify, and distribute this +.\" software and its documentation for any purpose and without +.\" fee is hereby granted, provided that the above copyright +.\" notice appear in all copies and that both that copyright +.\" notice and this permission notice appear in supporting +.\" documentation, and that the name of M.I.T. not be used in +.\" advertising or publicity pertaining to distribution of the +.\" software without specific, written prior permission. +.\" M.I.T. makes no representations about the suitability of +.\" this software for any purpose. It is provided "as is" +.\" without express or implied warranty. +.\" +.TH ARES_CREATE_QUERY 3 "20 Nov 2009" +.SH NAME +ares_create_query \- Compose a single-question DNS query buffer +.SH SYNOPSIS +.nf +.B #include +.PP +.B int ares_create_query(const char *\fIname\fP, int \fIdnsclass\fP,\ + int \fItype\fP, +.B unsigned short \fIid\fP, int \fIrd\fP,\ + unsigned char **\fIbuf\fP, +.B int *\fIbuflen\fP, int \fImax_udp_size\fP) +.fi +.SH DESCRIPTION +The +.B ares_create_query +function composes a DNS query with a single question. +The parameter +.I name +gives the query name as a NUL-terminated C string of period-separated +labels optionally ending with a period; periods and backslashes within +a label must be escaped with a backlash. The parameters +.I dnsclass +and +.I type +give the class and type of the query using the values defined in +.BR . +The parameter +.I id +gives a 16-bit identifier for the query. The parameter +.I rd +should be nonzero if recursion is desired, zero if not. The query +will be placed in an allocated buffer, a pointer to which will be +stored in the variable pointed to by +.IR buf , +and the length of which will be stored in the variable pointed to by +.IR buflen . +It is the caller's responsibility to free this buffer using +\fIares_free_string(3)\fP when it is no longer needed. +The parameter +.I max_udp_size +should be nonzero to activate EDNS. Usage of \fIares_create_query(3)\fP\ with +.I max_udp_size +set to zero is equivalent to \fIares_mkquery(3)\fP. +.SH RETURN VALUES +.B ares_create_query +can return any of the following values: +.TP 15 +.B ARES_SUCCESS +Construction of the DNS query succeeded. +.TP 15 +.B ARES_EBADNAME +The query name +.I name +could not be encoded as a domain name, either because it contained a +zero-length label or because it contained a label of more than 63 +characters. +.TP 15 +.B ARES_ENOMEM +Memory was exhausted. +.SH SEE ALSO +.BR ares_expand_name (3), +.BR ares_free_string (3) +.SH AUTHOR diff --git a/ares_create_query.c b/ares_create_query.c new file mode 100644 index 0000000..ef48ad8 --- /dev/null +++ b/ares_create_query.c @@ -0,0 +1,209 @@ + +/* Copyright 1998 by the Massachusetts Institute of Technology. + * + * Permission to use, copy, modify, and distribute this + * software and its documentation for any purpose and without + * fee is hereby granted, provided that the above copyright + * notice appear in all copies and that both that copyright + * notice and this permission notice appear in supporting + * documentation, and that the name of M.I.T. not be used in + * advertising or publicity pertaining to distribution of the + * software without specific, written prior permission. + * M.I.T. makes no representations about the suitability of + * this software for any purpose. It is provided "as is" + * without express or implied warranty. + */ + +#include "ares_setup.h" + +#ifdef HAVE_SYS_SOCKET_H +# include +#endif +#ifdef HAVE_NETINET_IN_H +# include +#endif +#ifdef HAVE_ARPA_NAMESER_H +# include +#else +# include "nameser.h" +#endif +#ifdef HAVE_ARPA_NAMESER_COMPAT_H +# include +#endif + +#include +#include +#include "ares.h" +#include "ares_dns.h" +#include "ares_private.h" + +/* Header format, from RFC 1035: + * 1 1 1 1 1 1 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * | ID | + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * |QR| Opcode |AA|TC|RD|RA| Z | RCODE | + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * | QDCOUNT | + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * | ANCOUNT | + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * | NSCOUNT | + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * | ARCOUNT | + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * + * AA, TC, RA, and RCODE are only set in responses. Brief description + * of the remaining fields: + * ID Identifier to match responses with queries + * QR Query (0) or response (1) + * Opcode For our purposes, always QUERY + * RD Recursion desired + * Z Reserved (zero) + * QDCOUNT Number of queries + * ANCOUNT Number of answers + * NSCOUNT Number of name server records + * ARCOUNT Number of additional records + * + * Question format, from RFC 1035: + * 1 1 1 1 1 1 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * | | + * / QNAME / + * / / + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * | QTYPE | + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * | QCLASS | + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * + * The query name is encoded as a series of labels, each represented + * as a one-byte length (maximum 63) followed by the text of the + * label. The list is terminated by a label of length zero (which can + * be thought of as the root domain). + */ + +int ares_create_query(const char *name, int dnsclass, int type, + unsigned short id, int rd, unsigned char **buf, + int *buflen, int max_udp_size) +{ + int len; + unsigned char *q; + const char *p; + + /* Set our results early, in case we bail out early with an error. */ + *buflen = 0; + *buf = NULL; + + /* Compute the length of the encoded name so we can check buflen. + * Start counting at 1 for the zero-length label at the end. */ + len = 1; + for (p = name; *p; p++) + { + if (*p == '\\' && *(p + 1) != 0) + p++; + len++; + } + /* If there are n periods in the name, there are n + 1 labels, and + * thus n + 1 length fields, unless the name is empty or ends with a + * period. So add 1 unless name is empty or ends with a period. + */ + if (*name && *(p - 1) != '.') + len++; + + /* Immediately reject names that are longer than the maximum of 255 + * bytes that's specified in RFC 1035 ("To simplify implementations, + * the total length of a domain name (i.e., label octets and label + * length octets) is restricted to 255 octets or less."). We aren't + * doing this just to be a stickler about RFCs. For names that are + * too long, 'dnscache' closes its TCP connection to us immediately + * (when using TCP) and ignores the request when using UDP, and + * BIND's named returns ServFail (TCP or UDP). Sending a request + * that we know will cause 'dnscache' to close the TCP connection is + * painful, since that makes any other outstanding requests on that + * connection fail. And sending a UDP request that we know + * 'dnscache' will ignore is bad because resources will be tied up + * until we time-out the request. + */ + if (len > MAXCDNAME) + return ARES_EBADNAME; + + *buflen = len + HFIXEDSZ + QFIXEDSZ + (max_udp_size ? EDNSFIXEDSZ : 0); + *buf = malloc(*buflen); + if (!*buf) + return ARES_ENOMEM; + + /* Set up the header. */ + q = *buf; + memset(q, 0, HFIXEDSZ); + DNS_HEADER_SET_QID(q, id); + DNS_HEADER_SET_OPCODE(q, QUERY); + if (rd) { + DNS_HEADER_SET_RD(q, 1); + } + else { + DNS_HEADER_SET_RD(q, 0); + } + DNS_HEADER_SET_QDCOUNT(q, 1); + + if (max_udp_size) { + DNS_HEADER_SET_ARCOUNT(q, 1); + } + + /* A name of "." is a screw case for the loop below, so adjust it. */ + if (strcmp(name, ".") == 0) + name++; + + /* Start writing out the name after the header. */ + q += HFIXEDSZ; + while (*name) + { + if (*name == '.') + return ARES_EBADNAME; + + /* Count the number of bytes in this label. */ + len = 0; + for (p = name; *p && *p != '.'; p++) + { + if (*p == '\\' && *(p + 1) != 0) + p++; + len++; + } + if (len > MAXLABEL) + return ARES_EBADNAME; + + /* Encode the length and copy the data. */ + *q++ = (unsigned char)len; + for (p = name; *p && *p != '.'; p++) + { + if (*p == '\\' && *(p + 1) != 0) + p++; + *q++ = *p; + } + + /* Go to the next label and repeat, unless we hit the end. */ + if (!*p) + break; + name = p + 1; + } + + /* Add the zero-length label at the end. */ + *q++ = 0; + + /* Finish off the question with the type and class. */ + DNS_QUESTION_SET_TYPE(q, type); + DNS_QUESTION_SET_CLASS(q, dnsclass); + + if (max_udp_size) + { + q += QFIXEDSZ; + memset(q, 0, EDNSFIXEDSZ); + q++; + DNS_RR_SET_TYPE(q, ns_t_opt); + DNS_RR_SET_CLASS(q, max_udp_size); + } + + return ARES_SUCCESS; +} diff --git a/ares_dns.h b/ares_dns.h index 34cf790..79f993b 100644 --- a/ares_dns.h +++ b/ares_dns.h @@ -95,9 +95,9 @@ #define DNS_RR_LEN(r) DNS__16BIT((r) + 8) /* Macros for constructing the fixed part of a DNS resource record */ -#define DNS_RR_SET_TYPE(r) DNS__SET16BIT(r, v) -#define DNS_RR_SET_CLASS(r) DNS__SET16BIT((r) + 2, v) -#define DNS_RR_SET_TTL(r) DNS__SET32BIT((r) + 4, v) -#define DNS_RR_SET_LEN(r) DNS__SET16BIT((r) + 8, v) +#define DNS_RR_SET_TYPE(r, v) DNS__SET16BIT(r, v) +#define DNS_RR_SET_CLASS(r, v) DNS__SET16BIT((r) + 2, v) +#define DNS_RR_SET_TTL(r, v) DNS__SET32BIT((r) + 4, v) +#define DNS_RR_SET_LEN(r, v) DNS__SET16BIT((r) + 8, v) #endif /* HEADER_CARES_DNS_H */ diff --git a/ares_init.c b/ares_init.c index f9eb054..a94a917 100644 --- a/ares_init.c +++ b/ares_init.c @@ -163,6 +163,7 @@ int ares_init_options(ares_channel *channelptr, struct ares_options *options, channel->rotate = -1; channel->udp_port = -1; channel->tcp_port = -1; + channel->ednspsz = -1; channel->socket_send_buffer_size = -1; channel->socket_receive_buffer_size = -1; channel->nservers = -1; @@ -453,6 +454,9 @@ static int init_by_options(ares_channel channel, && channel->socket_receive_buffer_size == -1) channel->socket_receive_buffer_size = options->socket_receive_buffer_size; + if ((optmask & ARES_OPT_EDNSPSZ) && channel->ednspsz == -1) + channel->ednspsz = options->ednspsz; + /* Copy the IPv4 servers, if given. */ if ((optmask & ARES_OPT_SERVERS) && channel->nservers == -1) { @@ -1358,6 +1362,9 @@ static int init_by_defaults(ares_channel channel) if (channel->tcp_port == -1) channel->tcp_port = htons(NAMESERVER_PORT); + if (channel->ednspsz == -1) + channel->ednspsz = EDNSPACKETSZ; + if (channel->nservers == -1) { /* If nobody specified servers, try a local named. */ channel->servers = malloc(sizeof(struct server_state)); diff --git a/ares_mkquery.3 b/ares_mkquery.3 index f7c5413..b2c90a9 100644 --- a/ares_mkquery.3 +++ b/ares_mkquery.3 @@ -25,6 +25,8 @@ ares_mkquery \- Compose a single-question DNS query buffer .B int *\fIbuflen\fP) .fi .SH DESCRIPTION +Deprecated function. See \fIares_create_query(3)\fP instead! + The .B ares_mkquery function composes a DNS query with a single question. @@ -50,6 +52,11 @@ and the length of which will be stored in the variable pointed to by .IR buflen . It is the caller's responsibility to free this buffer using \fIares_free_string(3)\fP when it is no longer needed. + +Usage of \fIares_mkquery(3)\fP is deprecated, whereas the function is +equivalent to \fIares_create_query(3)\fP with \fBmax_udp_size\fP set to +0. + .SH RETURN VALUES .B ares_mkquery can return any of the following values: diff --git a/ares_mkquery.c b/ares_mkquery.c index e33f13f..5aea914 100644 --- a/ares_mkquery.c +++ b/ares_mkquery.c @@ -15,181 +15,10 @@ */ #include "ares_setup.h" - -#ifdef HAVE_SYS_SOCKET_H -# include -#endif -#ifdef HAVE_NETINET_IN_H -# include -#endif -#ifdef HAVE_ARPA_NAMESER_H -# include -#else -# include "nameser.h" -#endif -#ifdef HAVE_ARPA_NAMESER_COMPAT_H -# include -#endif - -#include -#include #include "ares.h" -#include "ares_dns.h" -#include "ares_private.h" - -/* Header format, from RFC 1035: - * 1 1 1 1 1 1 - * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * | ID | - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * |QR| Opcode |AA|TC|RD|RA| Z | RCODE | - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * | QDCOUNT | - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * | ANCOUNT | - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * | NSCOUNT | - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * | ARCOUNT | - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * - * AA, TC, RA, and RCODE are only set in responses. Brief description - * of the remaining fields: - * ID Identifier to match responses with queries - * QR Query (0) or response (1) - * Opcode For our purposes, always QUERY - * RD Recursion desired - * Z Reserved (zero) - * QDCOUNT Number of queries - * ANCOUNT Number of answers - * NSCOUNT Number of name server records - * ARCOUNT Number of additional records - * - * Question format, from RFC 1035: - * 1 1 1 1 1 1 - * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * | | - * / QNAME / - * / / - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * | QTYPE | - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * | QCLASS | - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * - * The query name is encoded as a series of labels, each represented - * as a one-byte length (maximum 63) followed by the text of the - * label. The list is terminated by a label of length zero (which can - * be thought of as the root domain). - */ int ares_mkquery(const char *name, int dnsclass, int type, unsigned short id, int rd, unsigned char **buf, int *buflen) { - int len; - unsigned char *q; - const char *p; - - /* Set our results early, in case we bail out early with an error. */ - *buflen = 0; - *buf = NULL; - - /* Compute the length of the encoded name so we can check buflen. - * Start counting at 1 for the zero-length label at the end. */ - len = 1; - for (p = name; *p; p++) - { - if (*p == '\\' && *(p + 1) != 0) - p++; - len++; - } - /* If there are n periods in the name, there are n + 1 labels, and - * thus n + 1 length fields, unless the name is empty or ends with a - * period. So add 1 unless name is empty or ends with a period. - */ - if (*name && *(p - 1) != '.') - len++; - - /* Immediately reject names that are longer than the maximum of 255 - * bytes that's specified in RFC 1035 ("To simplify implementations, - * the total length of a domain name (i.e., label octets and label - * length octets) is restricted to 255 octets or less."). We aren't - * doing this just to be a stickler about RFCs. For names that are - * too long, 'dnscache' closes its TCP connection to us immediately - * (when using TCP) and ignores the request when using UDP, and - * BIND's named returns ServFail (TCP or UDP). Sending a request - * that we know will cause 'dnscache' to close the TCP connection is - * painful, since that makes any other outstanding requests on that - * connection fail. And sending a UDP request that we know - * 'dnscache' will ignore is bad because resources will be tied up - * until we time-out the request. - */ - if (len > MAXCDNAME) - return ARES_EBADNAME; - - *buflen = len + HFIXEDSZ + QFIXEDSZ; - *buf = malloc(*buflen); - if (!*buf) - return ARES_ENOMEM; - - /* Set up the header. */ - q = *buf; - memset(q, 0, HFIXEDSZ); - DNS_HEADER_SET_QID(q, id); - DNS_HEADER_SET_OPCODE(q, QUERY); - if (rd) { - DNS_HEADER_SET_RD(q, 1); - } - else { - DNS_HEADER_SET_RD(q, 0); - } - DNS_HEADER_SET_QDCOUNT(q, 1); - - /* A name of "." is a screw case for the loop below, so adjust it. */ - if (strcmp(name, ".") == 0) - name++; - - /* Start writing out the name after the header. */ - q += HFIXEDSZ; - while (*name) - { - if (*name == '.') - return ARES_EBADNAME; - - /* Count the number of bytes in this label. */ - len = 0; - for (p = name; *p && *p != '.'; p++) - { - if (*p == '\\' && *(p + 1) != 0) - p++; - len++; - } - if (len > MAXLABEL) - return ARES_EBADNAME; - - /* Encode the length and copy the data. */ - *q++ = (unsigned char)len; - for (p = name; *p && *p != '.'; p++) - { - if (*p == '\\' && *(p + 1) != 0) - p++; - *q++ = *p; - } - - /* Go to the next label and repeat, unless we hit the end. */ - if (!*p) - break; - name = p + 1; - } - - /* Add the zero-length label at the end. */ - *q++ = 0; - - /* Finish off the question with the type and class. */ - DNS_QUESTION_SET_TYPE(q, type); - DNS_QUESTION_SET_CLASS(q, dnsclass); - - return ARES_SUCCESS; + return ares_create_query(name, dnsclass, type, id, rd, buf, buflen, 0); } diff --git a/ares_private.h b/ares_private.h index 3c56bbc..8c8a08f 100644 --- a/ares_private.h +++ b/ares_private.h @@ -113,6 +113,13 @@ # define writev(s,ptr,cnt) ares_writev(s,ptr,cnt) #endif +/********* EDNS defines section ******/ +#define EDNSPACKETSZ 1280 /* Reasonable UDP payload size, as suggested + in RFC2671 */ +#define MAXENDSSZ 4096 /* Maximum (local) limit for edns packet size */ +#define EDNSFIXEDSZ 11 /* Size of EDNS header */ +/********* EDNS defines section ******/ + struct ares_addr { int family; union { @@ -260,6 +267,7 @@ struct ares_channeldata { struct apattern *sortlist; int nsort; char *lookups; + int ednspsz; /* For binding to local devices and/or IP addresses. Leave * them null/zero for no binding. diff --git a/ares_process.c b/ares_process.c index 0d29d00..b7c0bca 100644 --- a/ares_process.c +++ b/ares_process.c @@ -430,7 +430,7 @@ static void read_udp_packets(ares_channel channel, fd_set *read_fds, struct server_state *server; int i; ssize_t count; - unsigned char buf[PACKETSZ + 1]; + unsigned char buf[MAXENDSSZ + 1]; #ifdef HAVE_RECVFROM ares_socklen_t fromlen; union { @@ -541,7 +541,7 @@ static void process_answer(ares_channel channel, unsigned char *abuf, int alen, int whichserver, int tcp, struct timeval *now) { - int tc, rcode; + int tc, rcode, packetsz; unsigned short id; struct query *query; struct list_node* list_head; @@ -578,11 +578,34 @@ static void process_answer(ares_channel channel, unsigned char *abuf, if (!query) return; + packetsz = PACKETSZ; + /* If we use EDNS and server answers with one of these RCODES, the protocol + * extension is not understood by the responder. We must retry the query + * without EDNS enabled. + */ + if (channel->flags & ARES_FLAG_EDNS) + { + packetsz = channel->ednspsz; + if (rcode == NOTIMP || rcode == FORMERR || rcode == SERVFAIL) + { + int qlen = alen - EDNSFIXEDSZ; + channel->flags ^= ARES_FLAG_EDNS; + query->tcplen -= EDNSFIXEDSZ; + query->qlen -= EDNSFIXEDSZ; + query->tcpbuf[0] = (unsigned char)((qlen >> 8) & 0xff); + query->tcpbuf[1] = (unsigned char)(qlen & 0xff); + DNS_HEADER_SET_ARCOUNT(query->tcpbuf + 2, 0); + query->tcpbuf = realloc(query->tcpbuf, query->tcplen); + ares__send_query(channel, query, now); + return; + } + } + /* If we got a truncated UDP packet and are not ignoring truncation, * don't accept the packet, and switch the query to TCP if we hadn't * done so already. */ - if ((tc || alen > PACKETSZ) && !tcp && !(channel->flags & ARES_FLAG_IGNTC)) + if ((tc || alen > packetsz) && !tcp && !(channel->flags & ARES_FLAG_IGNTC)) { if (!query->using_tcp) { @@ -595,8 +618,8 @@ static void process_answer(ares_channel channel, unsigned char *abuf, /* Limit alen to PACKETSZ if we aren't using TCP (only relevant if we * are ignoring truncation. */ - if (alen > PACKETSZ && !tcp) - alen = PACKETSZ; + if (alen > packetsz && !tcp) + alen = packetsz; /* If we aren't passing through all error packets, discard packets * with SERVFAIL, NOTIMP, or REFUSED response codes. diff --git a/ares_query.c b/ares_query.c index 63652e2..ed6b6e8 100644 --- a/ares_query.c +++ b/ares_query.c @@ -114,8 +114,8 @@ void ares_query(ares_channel channel, const char *name, int dnsclass, /* Compose the query. */ rd = !(channel->flags & ARES_FLAG_NORECURSE); - status = ares_mkquery(name, dnsclass, type, channel->next_id, rd, &qbuf, - &qlen); + status = ares_create_query(name, dnsclass, type, channel->next_id, rd, &qbuf, + &qlen, (channel->flags & ARES_FLAG_EDNS) ? channel->ednspsz : 0); if (status != ARES_SUCCESS) { if (qbuf != NULL) free(qbuf); diff --git a/ares_send.c b/ares_send.c index 75a84f6..d3f734f 100644 --- a/ares_send.c +++ b/ares_send.c @@ -42,7 +42,7 @@ void ares_send(ares_channel channel, const unsigned char *qbuf, int qlen, ares_callback callback, void *arg) { struct query *query; - int i; + int i, packetsz; struct timeval now; /* Verify that the query is at least long enough to hold the header. */ @@ -109,7 +109,10 @@ void ares_send(ares_channel channel, const unsigned char *qbuf, int qlen, query->server_info[i].skip_server = 0; query->server_info[i].tcp_connection_generation = 0; } - query->using_tcp = (channel->flags & ARES_FLAG_USEVC) || qlen > PACKETSZ; + + packetsz = (channel->flags & ARES_FLAG_EDNS) ? channel->ednspsz : PACKETSZ; + query->using_tcp = (channel->flags & ARES_FLAG_USEVC) || qlen > packetsz; + query->error_status = ARES_ECONNREFUSED; query->timeouts = 0;