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author | Stephen Gallagher <sgallagh@redhat.com> | 2010-02-18 07:49:04 -0500 |
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committer | Stephen Gallagher <sgallagh@redhat.com> | 2010-02-18 13:48:45 -0500 |
commit | 1c48b5a62f73234ed26bb20f0ab345ab61cda0ab (patch) | |
tree | 0b6cddd567a862e1a7b5df23764869782a62ca78 /src/resolv/ares | |
parent | 8c56df3176f528fe0260974b3bf934173c4651ea (diff) | |
download | sssd-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.c | 140 | ||||
-rw-r--r-- | src/resolv/ares/ares_data.h | 68 | ||||
-rw-r--r-- | src/resolv/ares/ares_dns.h | 91 | ||||
-rw-r--r-- | src/resolv/ares/ares_parse_srv_reply.c | 183 | ||||
-rw-r--r-- | src/resolv/ares/ares_parse_srv_reply.h | 35 | ||||
-rw-r--r-- | src/resolv/ares/ares_parse_txt_reply.c | 204 | ||||
-rw-r--r-- | src/resolv/ares/ares_parse_txt_reply.h | 33 |
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__ */ |