summaryrefslogtreecommitdiffstats
path: root/src/resolv/ares
diff options
context:
space:
mode:
authorStephen Gallagher <sgallagh@redhat.com>2010-02-18 07:49:04 -0500
committerStephen Gallagher <sgallagh@redhat.com>2010-02-18 13:48:45 -0500
commit1c48b5a62f73234ed26bb20f0ab345ab61cda0ab (patch)
tree0b6cddd567a862e1a7b5df23764869782a62ca78 /src/resolv/ares
parent8c56df3176f528fe0260974b3bf934173c4651ea (diff)
downloadsssd-1c48b5a62f73234ed26bb20f0ab345ab61cda0ab.tar.gz
sssd-1c48b5a62f73234ed26bb20f0ab345ab61cda0ab.tar.xz
sssd-1c48b5a62f73234ed26bb20f0ab345ab61cda0ab.zip
Rename server/ directory to src/
Also update BUILD.txt
Diffstat (limited to 'src/resolv/ares')
-rw-r--r--src/resolv/ares/ares_data.c140
-rw-r--r--src/resolv/ares/ares_data.h68
-rw-r--r--src/resolv/ares/ares_dns.h91
-rw-r--r--src/resolv/ares/ares_parse_srv_reply.c183
-rw-r--r--src/resolv/ares/ares_parse_srv_reply.h35
-rw-r--r--src/resolv/ares/ares_parse_txt_reply.c204
-rw-r--r--src/resolv/ares/ares_parse_txt_reply.h33
7 files changed, 754 insertions, 0 deletions
diff --git a/src/resolv/ares/ares_data.c b/src/resolv/ares/ares_data.c
new file mode 100644
index 000000000..1cccaa55c
--- /dev/null
+++ b/src/resolv/ares/ares_data.c
@@ -0,0 +1,140 @@
+/* $Id: ares_data.c,v 1.2 2009-11-20 09:06:33 yangtse Exp $ */
+
+/* Copyright (C) 2009 by Daniel Stenberg
+ *
+ * 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 <stddef.h>
+#include <stdlib.h>
+
+#include "ares.h"
+#include "ares_data.h"
+
+/*
+** ares_free_data() - c-ares external API function.
+**
+** This function must be used by the application to free data memory that
+** has been internally allocated by some c-ares function and for which a
+** pointer has already been returned to the calling application. The list
+** of c-ares functions returning pointers that must be free'ed using this
+** function is:
+**
+** ares_parse_srv_reply()
+** ares_parse_txt_reply()
+*/
+
+void _ares_free_data(void *dataptr)
+{
+ struct ares_data *ptr;
+
+ if (!dataptr)
+ return;
+
+ ptr = (void *)((char *)dataptr - offsetof(struct ares_data, data));
+
+ if (ptr->mark != ARES_DATATYPE_MARK)
+ return;
+
+ switch (ptr->type)
+ {
+ case ARES_DATATYPE_SRV_REPLY:
+
+ if (ptr->data.srv_reply.next)
+ _ares_free_data(ptr->data.srv_reply.next);
+ if (ptr->data.srv_reply.host)
+ free(ptr->data.srv_reply.host);
+ break;
+
+ case ARES_DATATYPE_TXT_REPLY:
+
+ if (ptr->data.txt_reply.next)
+ _ares_free_data(ptr->data.txt_reply.next);
+ if (ptr->data.txt_reply.txt)
+ free(ptr->data.txt_reply.txt);
+ break;
+
+ default:
+ return;
+ }
+
+ free(ptr);
+}
+
+
+/*
+** ares_malloc_data() - c-ares internal helper function.
+**
+** This function allocates memory for a c-ares private ares_data struct
+** for the specified ares_datatype, initializes c-ares private fields
+** and zero initializes those which later might be used from the public
+** API. It returns an interior pointer which can be passed by c-ares
+** functions to the calling application, and that must be free'ed using
+** c-ares external API function ares_free_data().
+*/
+
+void *_ares_malloc_data(ares_datatype type)
+{
+ struct ares_data *ptr;
+
+ ptr = malloc(sizeof(struct ares_data));
+ if (!ptr)
+ return NULL;
+
+ switch (type)
+ {
+ case ARES_DATATYPE_SRV_REPLY:
+ ptr->data.srv_reply.next = NULL;
+ ptr->data.srv_reply.host = NULL;
+ ptr->data.srv_reply.priority = 0;
+ ptr->data.srv_reply.weight = 0;
+ ptr->data.srv_reply.port = 0;
+ break;
+
+ case ARES_DATATYPE_TXT_REPLY:
+ ptr->data.txt_reply.next = NULL;
+ ptr->data.txt_reply.txt = NULL;
+ ptr->data.txt_reply.length = 0;
+ break;
+
+ default:
+ free(ptr);
+ return NULL;
+ }
+
+ ptr->mark = ARES_DATATYPE_MARK;
+ ptr->type = type;
+
+ return &ptr->data;
+}
+
+
+/*
+** ares_get_datatype() - c-ares internal helper function.
+**
+** This function returns the ares_datatype of the data stored in a
+** private ares_data struct when given the public API pointer.
+*/
+
+ares_datatype ares_get_datatype(void * dataptr)
+{
+ struct ares_data *ptr;
+
+ ptr = (void *)((char *)dataptr - offsetof(struct ares_data, data));
+
+ if (ptr->mark == ARES_DATATYPE_MARK)
+ return ptr->type;
+
+ return ARES_DATATYPE_UNKNOWN;
+}
diff --git a/src/resolv/ares/ares_data.h b/src/resolv/ares/ares_data.h
new file mode 100644
index 000000000..d3606314e
--- /dev/null
+++ b/src/resolv/ares/ares_data.h
@@ -0,0 +1,68 @@
+/* $Id: ares_data.h,v 1.2 2009-11-23 12:03:33 yangtse Exp $ */
+
+/* Copyright (C) 2009 by Daniel Stenberg
+ *
+ * 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.
+ */
+
+#ifndef HAVE_ARES_DATA
+#include "resolv/ares/ares_parse_txt_reply.h"
+#include "resolv/ares/ares_parse_srv_reply.h"
+#endif /* HAVE_ARES_DATA */
+
+typedef enum {
+ ARES_DATATYPE_UNKNOWN = 1, /* unknown data type - introduced in 1.7.0 */
+ ARES_DATATYPE_SRV_REPLY, /* struct ares_srv_reply - introduced in 1.7.0 */
+ ARES_DATATYPE_TXT_REPLY, /* struct ares_txt_reply - introduced in 1.7.0 */
+#if 0
+ ARES_DATATYPE_ADDR6TTL, /* struct ares_addrttl */
+ ARES_DATATYPE_ADDRTTL, /* struct ares_addr6ttl */
+ ARES_DATATYPE_HOSTENT, /* struct hostent */
+ ARES_DATATYPE_OPTIONS, /* struct ares_options */
+#endif
+ ARES_DATATYPE_LAST /* not used - introduced in 1.7.0 */
+} ares_datatype;
+
+#define ARES_DATATYPE_MARK 0xbead
+
+/*
+ * ares_data struct definition is internal to c-ares and shall not
+ * be exposed by the public API in order to allow future changes
+ * and extensions to it without breaking ABI. This will be used
+ * internally by c-ares as the container of multiple types of data
+ * dynamically allocated for which a reference will be returned
+ * to the calling application.
+ *
+ * c-ares API functions returning a pointer to c-ares internally
+ * allocated data will actually be returning an interior pointer
+ * into this ares_data struct.
+ *
+ * All this is 'invisible' to the calling application, the only
+ * requirement is that this kind of data must be free'ed by the
+ * calling application using ares_free_data() with the pointer
+ * it has received from a previous c-ares function call.
+ */
+
+struct ares_data {
+ ares_datatype type; /* Actual data type identifier. */
+ unsigned int mark; /* Private ares_data signature. */
+ union {
+ struct ares_txt_reply txt_reply;
+ struct ares_srv_reply srv_reply;
+ } data;
+};
+
+void *_ares_malloc_data(ares_datatype type);
+void _ares_free_data(void *dataptr);
+
+ares_datatype ares_get_datatype(void * dataptr);
diff --git a/src/resolv/ares/ares_dns.h b/src/resolv/ares/ares_dns.h
new file mode 100644
index 000000000..c0a9dda65
--- /dev/null
+++ b/src/resolv/ares/ares_dns.h
@@ -0,0 +1,91 @@
+/* $Id: ares_dns.h,v 1.8 2007-02-16 14:22:08 yangtse Exp $ */
+
+/* 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.
+ */
+
+#ifndef ARES__DNS_H
+#define ARES__DNS_H
+
+#define DNS__16BIT(p) (((p)[0] << 8) | (p)[1])
+#define DNS__32BIT(p) (((p)[0] << 24) | ((p)[1] << 16) | \
+ ((p)[2] << 8) | (p)[3])
+
+#define DNS__SET16BIT(p, v) (((p)[0] = (unsigned char)(((v) >> 8) & 0xff)), \
+ ((p)[1] = (unsigned char)((v) & 0xff)))
+#define DNS__SET32BIT(p, v) (((p)[0] = (unsigned char)(((v) >> 24) & 0xff)), \
+ ((p)[1] = (unsigned char)(((v) >> 16) & 0xff)), \
+ ((p)[2] = (unsigned char)(((v) >> 8) & 0xff)), \
+ ((p)[3] = (unsigned char)((v) & 0xff)))
+
+#if 0
+/* we cannot use this approach on systems where we can't access 16/32 bit
+ data on un-aligned addresses */
+#define DNS__16BIT(p) ntohs(*(unsigned short*)(p))
+#define DNS__32BIT(p) ntohl(*(unsigned long*)(p))
+#define DNS__SET16BIT(p, v) *(unsigned short*)(p) = htons(v)
+#define DNS__SET32BIT(p, v) *(unsigned long*)(p) = htonl(v)
+#endif
+
+/* Macros for parsing a DNS header */
+#define DNS_HEADER_QID(h) DNS__16BIT(h)
+#define DNS_HEADER_QR(h) (((h)[2] >> 7) & 0x1)
+#define DNS_HEADER_OPCODE(h) (((h)[2] >> 3) & 0xf)
+#define DNS_HEADER_AA(h) (((h)[2] >> 2) & 0x1)
+#define DNS_HEADER_TC(h) (((h)[2] >> 1) & 0x1)
+#define DNS_HEADER_RD(h) ((h)[2] & 0x1)
+#define DNS_HEADER_RA(h) (((h)[3] >> 7) & 0x1)
+#define DNS_HEADER_Z(h) (((h)[3] >> 4) & 0x7)
+#define DNS_HEADER_RCODE(h) ((h)[3] & 0xf)
+#define DNS_HEADER_QDCOUNT(h) DNS__16BIT((h) + 4)
+#define DNS_HEADER_ANCOUNT(h) DNS__16BIT((h) + 6)
+#define DNS_HEADER_NSCOUNT(h) DNS__16BIT((h) + 8)
+#define DNS_HEADER_ARCOUNT(h) DNS__16BIT((h) + 10)
+
+/* Macros for constructing a DNS header */
+#define DNS_HEADER_SET_QID(h, v) DNS__SET16BIT(h, v)
+#define DNS_HEADER_SET_QR(h, v) ((h)[2] |= (unsigned char)(((v) & 0x1) << 7))
+#define DNS_HEADER_SET_OPCODE(h, v) ((h)[2] |= (unsigned char)(((v) & 0xf) << 3))
+#define DNS_HEADER_SET_AA(h, v) ((h)[2] |= (unsigned char)(((v) & 0x1) << 2))
+#define DNS_HEADER_SET_TC(h, v) ((h)[2] |= (unsigned char)(((v) & 0x1) << 1))
+#define DNS_HEADER_SET_RD(h, v) ((h)[2] |= (unsigned char)((v) & 0x1))
+#define DNS_HEADER_SET_RA(h, v) ((h)[3] |= (unsigned char)(((v) & 0x1) << 7))
+#define DNS_HEADER_SET_Z(h, v) ((h)[3] |= (unsigned char)(((v) & 0x7) << 4))
+#define DNS_HEADER_SET_RCODE(h, v) ((h)[3] |= (unsigned char)((v) & 0xf))
+#define DNS_HEADER_SET_QDCOUNT(h, v) DNS__SET16BIT((h) + 4, v)
+#define DNS_HEADER_SET_ANCOUNT(h, v) DNS__SET16BIT((h) + 6, v)
+#define DNS_HEADER_SET_NSCOUNT(h, v) DNS__SET16BIT((h) + 8, v)
+#define DNS_HEADER_SET_ARCOUNT(h, v) DNS__SET16BIT((h) + 10, v)
+
+/* Macros for parsing the fixed part of a DNS question */
+#define DNS_QUESTION_TYPE(q) DNS__16BIT(q)
+#define DNS_QUESTION_CLASS(q) DNS__16BIT((q) + 2)
+
+/* Macros for constructing the fixed part of a DNS question */
+#define DNS_QUESTION_SET_TYPE(q, v) DNS__SET16BIT(q, v)
+#define DNS_QUESTION_SET_CLASS(q, v) DNS__SET16BIT((q) + 2, v)
+
+/* Macros for parsing the fixed part of a DNS resource record */
+#define DNS_RR_TYPE(r) DNS__16BIT(r)
+#define DNS_RR_CLASS(r) DNS__16BIT((r) + 2)
+#define DNS_RR_TTL(r) DNS__32BIT((r) + 4)
+#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)
+
+#endif /* ARES__DNS_H */
diff --git a/src/resolv/ares/ares_parse_srv_reply.c b/src/resolv/ares/ares_parse_srv_reply.c
new file mode 100644
index 000000000..086c4dba0
--- /dev/null
+++ b/src/resolv/ares/ares_parse_srv_reply.c
@@ -0,0 +1,183 @@
+/*
+ SSSD
+
+ Async resolver - SRV records parsing
+
+ Authors:
+ Jakub Hrozek <jhrozek@redhat.com>
+
+ Copyright (C) Red Hat, Inc 2009
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/*
+ * This code is based on other c-ares parsing licensed as follows:
+
+ * 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 <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <arpa/nameser.h>
+#include <stdlib.h>
+#include <string.h>
+#include "ares.h"
+/* this drags in some private macros c-ares uses */
+#include "ares_dns.h"
+#include "ares_data.h"
+
+#include "ares_parse_srv_reply.h"
+
+int _ares_parse_srv_reply (const unsigned char *abuf, int alen,
+ struct ares_srv_reply **srv_out)
+{
+ unsigned int qdcount, ancount, i;
+ const unsigned char *aptr, *vptr;
+ int status, rr_type, rr_class, rr_len;
+ long len;
+ char *hostname = NULL, *rr_name = NULL;
+ struct ares_srv_reply *srv_head = NULL;
+ struct ares_srv_reply *srv_last = NULL;
+ struct ares_srv_reply *srv_curr;
+
+ /* Set *srv_out to NULL for all failure cases. */
+ *srv_out = NULL;
+
+ /* Give up if abuf doesn't have room for a header. */
+ if (alen < HFIXEDSZ)
+ return ARES_EBADRESP;
+
+ /* Fetch the question and answer count from the header. */
+ qdcount = DNS_HEADER_QDCOUNT (abuf);
+ ancount = DNS_HEADER_ANCOUNT (abuf);
+ if (qdcount != 1)
+ return ARES_EBADRESP;
+ if (ancount == 0)
+ return ARES_ENODATA;
+
+ /* Expand the name from the question, and skip past the question. */
+ aptr = abuf + HFIXEDSZ;
+ status = ares_expand_name (aptr, abuf, alen, &hostname, &len);
+ if (status != ARES_SUCCESS)
+ return status;
+
+ if (aptr + len + QFIXEDSZ > abuf + alen)
+ {
+ free (hostname);
+ return ARES_EBADRESP;
+ }
+ aptr += len + QFIXEDSZ;
+
+ /* Examine each answer resource record (RR) in turn. */
+ for (i = 0; i < (int) ancount; i++)
+ {
+ /* Decode the RR up to the data field. */
+ status = ares_expand_name (aptr, abuf, alen, &rr_name, &len);
+ if (status != ARES_SUCCESS)
+ {
+ break;
+ }
+ aptr += len;
+ if (aptr + RRFIXEDSZ > abuf + alen)
+ {
+ status = ARES_EBADRESP;
+ break;
+ }
+ rr_type = DNS_RR_TYPE (aptr);
+ rr_class = DNS_RR_CLASS (aptr);
+ rr_len = DNS_RR_LEN (aptr);
+ aptr += RRFIXEDSZ;
+
+ /* Check if we are really looking at a SRV record */
+ if (rr_class == C_IN && rr_type == T_SRV)
+ {
+ /* parse the SRV record itself */
+ if (rr_len < 6)
+ {
+ status = ARES_EBADRESP;
+ break;
+ }
+
+ /* Allocate storage for this SRV answer appending it to the list */
+ srv_curr = _ares_malloc_data(ARES_DATATYPE_SRV_REPLY);
+ if (!srv_curr)
+ {
+ status = ARES_ENOMEM;
+ break;
+ }
+ if (srv_last)
+ {
+ srv_last->next = srv_curr;
+ }
+ else
+ {
+ srv_head = srv_curr;
+ }
+ srv_last = srv_curr;
+
+ vptr = aptr;
+ srv_curr->priority = ntohs (*((const unsigned short *)vptr));
+ vptr += sizeof(const unsigned short);
+ srv_curr->weight = ntohs (*((const unsigned short *)vptr));
+ vptr += sizeof(const unsigned short);
+ srv_curr->port = ntohs (*((const unsigned short *)vptr));
+ vptr += sizeof(const unsigned short);
+
+ status = ares_expand_name (vptr, abuf, alen, &srv_curr->host, &len);
+ if (status != ARES_SUCCESS)
+ break;
+ }
+
+ /* Don't lose memory in the next iteration */
+ free(rr_name);
+ rr_name = NULL;
+
+ /* Move on to the next record */
+ aptr += rr_len;
+ }
+
+ if (hostname)
+ free (hostname);
+ if (rr_name)
+ free (rr_name);
+
+ /* clean up on error */
+ if (status != ARES_SUCCESS)
+ {
+ if (srv_head)
+ _ares_free_data (srv_head);
+ return status;
+ }
+
+ /* everything looks fine, return the data */
+ *srv_out = srv_head;
+
+ return ARES_SUCCESS;
+}
diff --git a/src/resolv/ares/ares_parse_srv_reply.h b/src/resolv/ares/ares_parse_srv_reply.h
new file mode 100644
index 000000000..29c6e08d1
--- /dev/null
+++ b/src/resolv/ares/ares_parse_srv_reply.h
@@ -0,0 +1,35 @@
+/*
+ Authors:
+ Jakub Hrozek <jhrozek@redhat.com>
+
+ Copyright (C) 2009 Red Hat
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef __ARES_PARSE_SRV_REPLY_H__
+#define __ARES_PARSE_SRV_REPLY_H__
+
+struct ares_srv_reply {
+ struct ares_srv_reply *next;
+ char *host;
+ unsigned short priority;
+ unsigned short weight;
+ unsigned short port;
+};
+
+int _ares_parse_srv_reply (const unsigned char *abuf, int alen,
+ struct ares_srv_reply **srv_out);
+
+#endif /* __ARES_PARSE_SRV_REPLY_H__ */
diff --git a/src/resolv/ares/ares_parse_txt_reply.c b/src/resolv/ares/ares_parse_txt_reply.c
new file mode 100644
index 000000000..d710e8f98
--- /dev/null
+++ b/src/resolv/ares/ares_parse_txt_reply.c
@@ -0,0 +1,204 @@
+/*
+ SSSD
+
+ Async resolver - TXT records parsing
+
+ Authors:
+ Jakub Hrozek <jhrozek@redhat.com>
+
+ Copyright (C) Red Hat, Inc 2009
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/*
+ * This code is based on other c-ares parsing licensed as follows:
+
+ * 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 <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <arpa/nameser.h>
+#include <stdlib.h>
+#include <string.h>
+#include "ares.h"
+/* this drags in some private macros c-ares uses */
+#include "ares_dns.h"
+#include "ares_data.h"
+
+#include "ares_parse_txt_reply.h"
+
+int _ares_parse_txt_reply (const unsigned char *abuf, int alen,
+ struct ares_txt_reply **txt_out)
+{
+ size_t substr_len, str_len;
+ unsigned int qdcount, ancount, i;
+ const unsigned char *aptr;
+ const unsigned char *strptr;
+ int status, rr_type, rr_class, rr_len;
+ long len;
+ char *hostname = NULL, *rr_name = NULL;
+ struct ares_txt_reply *txt_head = NULL;
+ struct ares_txt_reply *txt_last = NULL;
+ struct ares_txt_reply *txt_curr;
+
+ /* Set *txt_out to NULL for all failure cases. */
+ *txt_out = NULL;
+
+ /* Give up if abuf doesn't have room for a header. */
+ if (alen < HFIXEDSZ)
+ return ARES_EBADRESP;
+
+ /* Fetch the question and answer count from the header. */
+ qdcount = DNS_HEADER_QDCOUNT(abuf);
+ ancount = DNS_HEADER_ANCOUNT(abuf);
+ if (qdcount != 1)
+ return ARES_EBADRESP;
+ if (ancount == 0)
+ return ARES_ENODATA;
+
+ /* Expand the name from the question, and skip past the question. */
+ aptr = abuf + HFIXEDSZ;
+ status = ares_expand_name(aptr, abuf, alen, &hostname, &len);
+ if (status != ARES_SUCCESS)
+ return status;
+
+ if (aptr + len + QFIXEDSZ > abuf + alen)
+ {
+ free (hostname);
+ return ARES_EBADRESP;
+ }
+ aptr += len + QFIXEDSZ;
+
+ /* Examine each answer resource record (RR) in turn. */
+ for (i = 0; i < (int) ancount; i++)
+ {
+ /* Decode the RR up to the data field. */
+ status = ares_expand_name(aptr, abuf, alen, &rr_name, &len);
+ if (status != ARES_SUCCESS)
+ {
+ break;
+ }
+ aptr += len;
+ if (aptr + RRFIXEDSZ > abuf + alen)
+ {
+ status = ARES_EBADRESP;
+ break;
+ }
+ rr_type = DNS_RR_TYPE(aptr);
+ rr_class = DNS_RR_CLASS(aptr);
+ rr_len = DNS_RR_LEN(aptr);
+ aptr += RRFIXEDSZ;
+
+ /* Check if we are really looking at a TXT record */
+ if (rr_class == C_IN && rr_type == T_TXT)
+ {
+ /* Allocate storage for this TXT answer appending it to the list */
+ txt_curr = _ares_malloc_data(ARES_DATATYPE_TXT_REPLY);
+ if (!txt_curr)
+ {
+ status = ARES_ENOMEM;
+ break;
+ }
+ if (txt_last)
+ {
+ txt_last->next = txt_curr;
+ }
+ else
+ {
+ txt_head = txt_curr;
+ }
+ txt_last = txt_curr;
+
+ /*
+ * There may be multiple substrings in a single TXT record. Each
+ * substring may be up to 255 characters in length, with a
+ * "length byte" indicating the size of the substring payload.
+ * RDATA contains both the length-bytes and payloads of all
+ * substrings contained therein.
+ */
+
+ /* Compute total length to allow a single memory allocation */
+ strptr = aptr;
+ while (strptr < (aptr + rr_len))
+ {
+ substr_len = (unsigned char)*strptr;
+ txt_curr->length += substr_len;
+ strptr += substr_len + 1;
+ }
+
+ /* Including null byte */
+ txt_curr->txt = malloc (txt_curr->length + 1);
+ if (txt_curr->txt == NULL)
+ {
+ status = ARES_ENOMEM;
+ break;
+ }
+
+ /* Step through the list of substrings, concatenating them */
+ str_len = 0;
+ strptr = aptr;
+ while (strptr < (aptr + rr_len))
+ {
+ substr_len = (unsigned char)*strptr;
+ strptr++;
+ memcpy ((char *) txt_curr->txt + str_len, strptr, substr_len);
+ str_len += substr_len;
+ strptr += substr_len;
+ }
+ /* Make sure we NULL-terminate */
+ *((char *) txt_curr->txt + txt_curr->length) = '\0';
+ }
+
+ /* Don't lose memory in the next iteration */
+ free(rr_name);
+ rr_name = NULL;
+
+ /* Move on to the next record */
+ aptr += rr_len;
+ }
+
+ if (hostname)
+ free (hostname);
+ if (rr_name)
+ free (rr_name);
+
+ /* clean up on error */
+ if (status != ARES_SUCCESS)
+ {
+ if (txt_head)
+ _ares_free_data (txt_head);
+ return status;
+ }
+
+ /* everything looks fine, return the data */
+ *txt_out = txt_head;
+
+ return ARES_SUCCESS;
+}
diff --git a/src/resolv/ares/ares_parse_txt_reply.h b/src/resolv/ares/ares_parse_txt_reply.h
new file mode 100644
index 000000000..216e2c0d1
--- /dev/null
+++ b/src/resolv/ares/ares_parse_txt_reply.h
@@ -0,0 +1,33 @@
+/*
+ Authors:
+ Jakub Hrozek <jhrozek@redhat.com>
+
+ Copyright (C) 2009 Red Hat
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef __ARES_PARSE_TXT_REPLY_H__
+#define __ARES_PARSE_TXT_REPLY_H__
+
+struct ares_txt_reply {
+ struct ares_txt_reply *next;
+ unsigned char *txt;
+ size_t length; /* length excludes null termination */
+};
+
+int _ares_parse_txt_reply(const unsigned char* abuf, int alen,
+ struct ares_txt_reply **txt_out);
+
+#endif /* __ARES_PARSE_TXT_REPLY_H__ */