freebsd-dev/lib/libcapsicum/libcapsicum_dns.c
Mariusz Zaborski bd1da0a002 Approved, oprócz użycie RESTORE_ERRNO() do ustawiania errno.
Change the nvlist_recv() function to take additional argument that
specifies flags expected on the received nvlist. Receiving a nvlist with
different set of flags than the ones we expect might lead to undefined
behaviour, which might be potentially dangerous.

Update consumers of this and related functions and update the tests.

Approved by:	pjd (mentor)

Update man page for nvlist_unpack, nvlist_recv, nvlist_xfer, cap_recv_nvlist
and cap_xfer_nvlist.

Reviewed by:	AllanJude
Approved by:	pjd (mentor)
2015-05-02 17:45:52 +00:00

366 lines
9.5 KiB
C

/*-
* Copyright (c) 2012-2013 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by Pawel Jakub Dawidek under sponsorship from
* the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <assert.h>
#include <netdb.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <nv.h>
#include "libcapsicum.h"
#include "libcapsicum_dns.h"
static struct hostent hent;
static void
hostent_free(struct hostent *hp)
{
unsigned int ii;
free(hp->h_name);
hp->h_name = NULL;
if (hp->h_aliases != NULL) {
for (ii = 0; hp->h_aliases[ii] != NULL; ii++)
free(hp->h_aliases[ii]);
free(hp->h_aliases);
hp->h_aliases = NULL;
}
if (hp->h_addr_list != NULL) {
for (ii = 0; hp->h_addr_list[ii] != NULL; ii++)
free(hp->h_addr_list[ii]);
free(hp->h_addr_list);
hp->h_addr_list = NULL;
}
}
static struct hostent *
hostent_unpack(const nvlist_t *nvl, struct hostent *hp)
{
unsigned int ii, nitems;
char nvlname[64];
int n;
hostent_free(hp);
hp->h_name = strdup(nvlist_get_string(nvl, "name"));
if (hp->h_name == NULL)
goto fail;
hp->h_addrtype = (int)nvlist_get_number(nvl, "addrtype");
hp->h_length = (int)nvlist_get_number(nvl, "length");
nitems = (unsigned int)nvlist_get_number(nvl, "naliases");
hp->h_aliases = calloc(sizeof(hp->h_aliases[0]), nitems + 1);
if (hp->h_aliases == NULL)
goto fail;
for (ii = 0; ii < nitems; ii++) {
n = snprintf(nvlname, sizeof(nvlname), "alias%u", ii);
assert(n > 0 && n < (int)sizeof(nvlname));
hp->h_aliases[ii] =
strdup(nvlist_get_string(nvl, nvlname));
if (hp->h_aliases[ii] == NULL)
goto fail;
}
hp->h_aliases[ii] = NULL;
nitems = (unsigned int)nvlist_get_number(nvl, "naddrs");
hp->h_addr_list = calloc(sizeof(hp->h_addr_list[0]), nitems + 1);
if (hp->h_addr_list == NULL)
goto fail;
for (ii = 0; ii < nitems; ii++) {
hp->h_addr_list[ii] = malloc(hp->h_length);
if (hp->h_addr_list[ii] == NULL)
goto fail;
n = snprintf(nvlname, sizeof(nvlname), "addr%u", ii);
assert(n > 0 && n < (int)sizeof(nvlname));
bcopy(nvlist_get_binary(nvl, nvlname, NULL),
hp->h_addr_list[ii], hp->h_length);
}
hp->h_addr_list[ii] = NULL;
return (hp);
fail:
hostent_free(hp);
h_errno = NO_RECOVERY;
return (NULL);
}
struct hostent *
cap_gethostbyname(cap_channel_t *chan, const char *name)
{
return (cap_gethostbyname2(chan, name, AF_INET));
}
struct hostent *
cap_gethostbyname2(cap_channel_t *chan, const char *name, int type)
{
struct hostent *hp;
nvlist_t *nvl;
nvl = nvlist_create(0);
nvlist_add_string(nvl, "cmd", "gethostbyname");
nvlist_add_number(nvl, "family", (uint64_t)type);
nvlist_add_string(nvl, "name", name);
nvl = cap_xfer_nvlist(chan, nvl, 0);
if (nvl == NULL) {
h_errno = NO_RECOVERY;
return (NULL);
}
if (nvlist_get_number(nvl, "error") != 0) {
h_errno = (int)nvlist_get_number(nvl, "error");
nvlist_destroy(nvl);
return (NULL);
}
hp = hostent_unpack(nvl, &hent);
nvlist_destroy(nvl);
return (hp);
}
struct hostent *
cap_gethostbyaddr(cap_channel_t *chan, const void *addr, socklen_t len,
int type)
{
struct hostent *hp;
nvlist_t *nvl;
nvl = nvlist_create(0);
nvlist_add_string(nvl, "cmd", "gethostbyaddr");
nvlist_add_binary(nvl, "addr", addr, (size_t)len);
nvlist_add_number(nvl, "family", (uint64_t)type);
nvl = cap_xfer_nvlist(chan, nvl, 0);
if (nvl == NULL) {
h_errno = NO_RECOVERY;
return (NULL);
}
if (nvlist_get_number(nvl, "error") != 0) {
h_errno = (int)nvlist_get_number(nvl, "error");
nvlist_destroy(nvl);
return (NULL);
}
hp = hostent_unpack(nvl, &hent);
nvlist_destroy(nvl);
return (hp);
}
static struct addrinfo *
addrinfo_unpack(const nvlist_t *nvl)
{
struct addrinfo *ai;
const void *addr;
size_t addrlen;
const char *canonname;
addr = nvlist_get_binary(nvl, "ai_addr", &addrlen);
ai = malloc(sizeof(*ai) + addrlen);
if (ai == NULL)
return (NULL);
ai->ai_flags = (int)nvlist_get_number(nvl, "ai_flags");
ai->ai_family = (int)nvlist_get_number(nvl, "ai_family");
ai->ai_socktype = (int)nvlist_get_number(nvl, "ai_socktype");
ai->ai_protocol = (int)nvlist_get_number(nvl, "ai_protocol");
ai->ai_addrlen = (socklen_t)addrlen;
canonname = nvlist_get_string(nvl, "ai_canonname");
if (canonname != NULL) {
ai->ai_canonname = strdup(canonname);
if (ai->ai_canonname == NULL) {
free(ai);
return (NULL);
}
} else {
ai->ai_canonname = NULL;
}
ai->ai_addr = (void *)(ai + 1);
bcopy(addr, ai->ai_addr, addrlen);
ai->ai_next = NULL;
return (ai);
}
int
cap_getaddrinfo(cap_channel_t *chan, const char *hostname, const char *servname,
const struct addrinfo *hints, struct addrinfo **res)
{
struct addrinfo *firstai, *prevai, *curai;
unsigned int ii;
const nvlist_t *nvlai;
char nvlname[64];
nvlist_t *nvl;
int error, n;
nvl = nvlist_create(0);
nvlist_add_string(nvl, "cmd", "getaddrinfo");
nvlist_add_string(nvl, "hostname", hostname);
nvlist_add_string(nvl, "servname", servname);
if (hints != NULL) {
nvlist_add_number(nvl, "hints.ai_flags",
(uint64_t)hints->ai_flags);
nvlist_add_number(nvl, "hints.ai_family",
(uint64_t)hints->ai_family);
nvlist_add_number(nvl, "hints.ai_socktype",
(uint64_t)hints->ai_socktype);
nvlist_add_number(nvl, "hints.ai_protocol",
(uint64_t)hints->ai_protocol);
}
nvl = cap_xfer_nvlist(chan, nvl, 0);
if (nvl == NULL)
return (EAI_MEMORY);
if (nvlist_get_number(nvl, "error") != 0) {
error = (int)nvlist_get_number(nvl, "error");
nvlist_destroy(nvl);
return (error);
}
nvlai = NULL;
firstai = prevai = curai = NULL;
for (ii = 0; ; ii++) {
n = snprintf(nvlname, sizeof(nvlname), "res%u", ii);
assert(n > 0 && n < (int)sizeof(nvlname));
if (!nvlist_exists_nvlist(nvl, nvlname))
break;
nvlai = nvlist_get_nvlist(nvl, nvlname);
curai = addrinfo_unpack(nvlai);
if (curai == NULL)
break;
if (prevai != NULL)
prevai->ai_next = curai;
else if (firstai == NULL)
firstai = curai;
prevai = curai;
}
nvlist_destroy(nvl);
if (curai == NULL && nvlai != NULL) {
if (firstai == NULL)
freeaddrinfo(firstai);
return (EAI_MEMORY);
}
*res = firstai;
return (0);
}
int
cap_getnameinfo(cap_channel_t *chan, const struct sockaddr *sa, socklen_t salen,
char *host, size_t hostlen, char *serv, size_t servlen, int flags)
{
nvlist_t *nvl;
int error;
nvl = nvlist_create(0);
nvlist_add_string(nvl, "cmd", "getnameinfo");
nvlist_add_number(nvl, "hostlen", (uint64_t)hostlen);
nvlist_add_number(nvl, "servlen", (uint64_t)servlen);
nvlist_add_binary(nvl, "sa", sa, (size_t)salen);
nvlist_add_number(nvl, "flags", (uint64_t)flags);
nvl = cap_xfer_nvlist(chan, nvl, 0);
if (nvl == NULL)
return (EAI_MEMORY);
if (nvlist_get_number(nvl, "error") != 0) {
error = (int)nvlist_get_number(nvl, "error");
nvlist_destroy(nvl);
return (error);
}
if (host != NULL)
strlcpy(host, nvlist_get_string(nvl, "host"), hostlen + 1);
if (serv != NULL)
strlcpy(serv, nvlist_get_string(nvl, "serv"), servlen + 1);
nvlist_destroy(nvl);
return (0);
}
static void
limit_remove(nvlist_t *limits, const char *prefix)
{
const char *name;
size_t prefixlen;
void *cookie;
prefixlen = strlen(prefix);
again:
cookie = NULL;
while ((name = nvlist_next(limits, NULL, &cookie)) != NULL) {
if (strncmp(name, prefix, prefixlen) == 0) {
nvlist_free(limits, name);
goto again;
}
}
}
int
cap_dns_type_limit(cap_channel_t *chan, const char * const *types,
size_t ntypes)
{
nvlist_t *limits;
unsigned int i;
char nvlname[64];
int n;
if (cap_limit_get(chan, &limits) < 0)
return (-1);
if (limits == NULL)
limits = nvlist_create(0);
else
limit_remove(limits, "type");
for (i = 0; i < ntypes; i++) {
n = snprintf(nvlname, sizeof(nvlname), "type%u", i);
assert(n > 0 && n < (int)sizeof(nvlname));
nvlist_add_string(limits, nvlname, types[i]);
}
return (cap_limit_set(chan, limits));
}
int
cap_dns_family_limit(cap_channel_t *chan, const int *families,
size_t nfamilies)
{
nvlist_t *limits;
unsigned int i;
char nvlname[64];
int n;
if (cap_limit_get(chan, &limits) < 0)
return (-1);
if (limits == NULL)
limits = nvlist_create(0);
else
limit_remove(limits, "family");
for (i = 0; i < nfamilies; i++) {
n = snprintf(nvlname, sizeof(nvlname), "family%u", i);
assert(n > 0 && n < (int)sizeof(nvlname));
nvlist_add_number(limits, nvlname, (uint64_t)families[i]);
}
return (cap_limit_set(chan, limits));
}