freebsd-dev/sys/netgraph/ng_checksum.c
Lutz Donnerhacke 687e510e5c netgraph/ng_checksum: Fix double free error
m_pullup(9) frees the mbuf(9) chain in the case of an allocation error.
The mbuf chain must not be freed again in this case.

PR:		255874
Submitted by:	<lylgood@foxmail.com>
Approved by:	markj
MFC after:	1 week
Differential Revision: https://reviews.freebsd.org/D30273
2021-05-16 19:39:51 +02:00

729 lines
16 KiB
C

/*-
* Copyright (c) 2015 Dmitry Vagin <daemon.hammer@ya.ru>
* All rights reserved.
*
* 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 AUTHOR 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 AUTHOR 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 "opt_inet.h"
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/endian.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <net/bpf.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <net/if_vlan_var.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/ip6.h>
#include <netinet/tcp.h>
#include <netinet/udp.h>
#include <machine/in_cksum.h>
#include <netgraph/ng_message.h>
#include <netgraph/ng_parse.h>
#include <netgraph/netgraph.h>
#include <netgraph/ng_checksum.h>
/* private data */
struct ng_checksum_priv {
hook_p in;
hook_p out;
uint8_t dlt; /* DLT_XXX from bpf.h */
struct ng_checksum_config *conf;
struct ng_checksum_stats stats;
};
typedef struct ng_checksum_priv *priv_p;
/* Netgraph methods */
static ng_constructor_t ng_checksum_constructor;
static ng_rcvmsg_t ng_checksum_rcvmsg;
static ng_shutdown_t ng_checksum_shutdown;
static ng_newhook_t ng_checksum_newhook;
static ng_rcvdata_t ng_checksum_rcvdata;
static ng_disconnect_t ng_checksum_disconnect;
#define ERROUT(x) { error = (x); goto done; }
static const struct ng_parse_struct_field ng_checksum_config_type_fields[]
= NG_CHECKSUM_CONFIG_TYPE;
static const struct ng_parse_type ng_checksum_config_type = {
&ng_parse_struct_type,
&ng_checksum_config_type_fields
};
static const struct ng_parse_struct_field ng_checksum_stats_fields[]
= NG_CHECKSUM_STATS_TYPE;
static const struct ng_parse_type ng_checksum_stats_type = {
&ng_parse_struct_type,
&ng_checksum_stats_fields
};
static const struct ng_cmdlist ng_checksum_cmdlist[] = {
{
NGM_CHECKSUM_COOKIE,
NGM_CHECKSUM_GETDLT,
"getdlt",
NULL,
&ng_parse_uint8_type
},
{
NGM_CHECKSUM_COOKIE,
NGM_CHECKSUM_SETDLT,
"setdlt",
&ng_parse_uint8_type,
NULL
},
{
NGM_CHECKSUM_COOKIE,
NGM_CHECKSUM_GETCONFIG,
"getconfig",
NULL,
&ng_checksum_config_type
},
{
NGM_CHECKSUM_COOKIE,
NGM_CHECKSUM_SETCONFIG,
"setconfig",
&ng_checksum_config_type,
NULL
},
{
NGM_CHECKSUM_COOKIE,
NGM_CHECKSUM_GET_STATS,
"getstats",
NULL,
&ng_checksum_stats_type
},
{
NGM_CHECKSUM_COOKIE,
NGM_CHECKSUM_CLR_STATS,
"clrstats",
NULL,
NULL
},
{
NGM_CHECKSUM_COOKIE,
NGM_CHECKSUM_GETCLR_STATS,
"getclrstats",
NULL,
&ng_checksum_stats_type
},
{ 0 }
};
static struct ng_type typestruct = {
.version = NG_ABI_VERSION,
.name = NG_CHECKSUM_NODE_TYPE,
.constructor = ng_checksum_constructor,
.rcvmsg = ng_checksum_rcvmsg,
.shutdown = ng_checksum_shutdown,
.newhook = ng_checksum_newhook,
.rcvdata = ng_checksum_rcvdata,
.disconnect = ng_checksum_disconnect,
.cmdlist = ng_checksum_cmdlist,
};
NETGRAPH_INIT(checksum, &typestruct);
static int
ng_checksum_constructor(node_p node)
{
priv_p priv;
priv = malloc(sizeof(*priv), M_NETGRAPH, M_WAITOK|M_ZERO);
priv->dlt = DLT_RAW;
NG_NODE_SET_PRIVATE(node, priv);
return (0);
}
static int
ng_checksum_newhook(node_p node, hook_p hook, const char *name)
{
const priv_p priv = NG_NODE_PRIVATE(node);
if (strncmp(name, NG_CHECKSUM_HOOK_IN, strlen(NG_CHECKSUM_HOOK_IN)) == 0) {
priv->in = hook;
} else if (strncmp(name, NG_CHECKSUM_HOOK_OUT, strlen(NG_CHECKSUM_HOOK_OUT)) == 0) {
priv->out = hook;
} else
return (EINVAL);
return (0);
}
static int
ng_checksum_rcvmsg(node_p node, item_p item, hook_p lasthook)
{
const priv_p priv = NG_NODE_PRIVATE(node);
struct ng_checksum_config *conf, *newconf;
struct ng_mesg *msg;
struct ng_mesg *resp = NULL;
int error = 0;
NGI_GET_MSG(item, msg);
if (msg->header.typecookie != NGM_CHECKSUM_COOKIE)
ERROUT(EINVAL);
switch (msg->header.cmd)
{
case NGM_CHECKSUM_GETDLT:
NG_MKRESPONSE(resp, msg, sizeof(uint8_t), M_WAITOK);
if (resp == NULL)
ERROUT(ENOMEM);
*((uint8_t *) resp->data) = priv->dlt;
break;
case NGM_CHECKSUM_SETDLT:
if (msg->header.arglen != sizeof(uint8_t))
ERROUT(EINVAL);
switch (*(uint8_t *) msg->data)
{
case DLT_EN10MB:
case DLT_RAW:
priv->dlt = *(uint8_t *) msg->data;
break;
default:
ERROUT(EINVAL);
}
break;
case NGM_CHECKSUM_GETCONFIG:
if (priv->conf == NULL)
ERROUT(0);
NG_MKRESPONSE(resp, msg, sizeof(struct ng_checksum_config), M_WAITOK);
if (resp == NULL)
ERROUT(ENOMEM);
bcopy(priv->conf, resp->data, sizeof(struct ng_checksum_config));
break;
case NGM_CHECKSUM_SETCONFIG:
conf = (struct ng_checksum_config *) msg->data;
if (msg->header.arglen != sizeof(struct ng_checksum_config))
ERROUT(EINVAL);
conf->csum_flags &= NG_CHECKSUM_CSUM_IPV4|NG_CHECKSUM_CSUM_IPV6;
conf->csum_offload &= NG_CHECKSUM_CSUM_IPV4|NG_CHECKSUM_CSUM_IPV6;
newconf = malloc(sizeof(struct ng_checksum_config), M_NETGRAPH, M_WAITOK|M_ZERO);
bcopy(conf, newconf, sizeof(struct ng_checksum_config));
if (priv->conf)
free(priv->conf, M_NETGRAPH);
priv->conf = newconf;
break;
case NGM_CHECKSUM_GET_STATS:
case NGM_CHECKSUM_CLR_STATS:
case NGM_CHECKSUM_GETCLR_STATS:
if (msg->header.cmd != NGM_CHECKSUM_CLR_STATS) {
NG_MKRESPONSE(resp, msg, sizeof(struct ng_checksum_stats), M_WAITOK);
if (resp == NULL)
ERROUT(ENOMEM);
bcopy(&(priv->stats), resp->data, sizeof(struct ng_checksum_stats));
}
if (msg->header.cmd != NGM_CHECKSUM_GET_STATS)
bzero(&(priv->stats), sizeof(struct ng_checksum_stats));
break;
default:
ERROUT(EINVAL);
}
done:
NG_RESPOND_MSG(error, node, item, resp);
NG_FREE_MSG(msg);
return (error);
}
#define PULLUP_CHECK(mbuf, length) do { \
pullup_len += length; \
if (((mbuf)->m_pkthdr.len < pullup_len) || \
(pullup_len > MHLEN)) { \
return (EINVAL); \
} \
if ((mbuf)->m_len < pullup_len && \
(((mbuf) = m_pullup((mbuf), pullup_len)) == NULL)) { \
return (ENOBUFS); \
} \
} while (0)
#ifdef INET
static int
checksum_ipv4(priv_p priv, struct mbuf *m, int l3_offset)
{
struct ip *ip4;
int pullup_len;
int hlen, plen;
int processed = 0;
pullup_len = l3_offset;
PULLUP_CHECK(m, sizeof(struct ip));
ip4 = (struct ip *) mtodo(m, l3_offset);
if (ip4->ip_v != IPVERSION)
return (EOPNOTSUPP);
hlen = ip4->ip_hl << 2;
plen = ntohs(ip4->ip_len);
if (hlen < sizeof(struct ip) || m->m_pkthdr.len < l3_offset + plen)
return (EINVAL);
if (m->m_pkthdr.csum_flags & CSUM_IP) {
ip4->ip_sum = 0;
if ((priv->conf->csum_offload & CSUM_IP) == 0) {
if (hlen == sizeof(struct ip))
ip4->ip_sum = in_cksum_hdr(ip4);
else
ip4->ip_sum = in_cksum_skip(m, l3_offset + hlen, l3_offset);
m->m_pkthdr.csum_flags &= ~CSUM_IP;
}
processed = 1;
}
pullup_len = l3_offset + hlen;
/* We can not calculate a checksum fragmented packets */
if (ip4->ip_off & htons(IP_MF|IP_OFFMASK)) {
m->m_pkthdr.csum_flags &= ~(CSUM_TCP|CSUM_UDP);
return (0);
}
switch (ip4->ip_p)
{
case IPPROTO_TCP:
if (m->m_pkthdr.csum_flags & CSUM_TCP) {
struct tcphdr *th;
PULLUP_CHECK(m, sizeof(struct tcphdr));
th = (struct tcphdr *) mtodo(m, l3_offset + hlen);
th->th_sum = in_pseudo(ip4->ip_src.s_addr,
ip4->ip_dst.s_addr, htons(ip4->ip_p + plen - hlen));
if ((priv->conf->csum_offload & CSUM_TCP) == 0) {
th->th_sum = in_cksum_skip(m, l3_offset + plen, l3_offset + hlen);
m->m_pkthdr.csum_flags &= ~CSUM_TCP;
}
processed = 1;
}
m->m_pkthdr.csum_flags &= ~CSUM_UDP;
break;
case IPPROTO_UDP:
if (m->m_pkthdr.csum_flags & CSUM_UDP) {
struct udphdr *uh;
PULLUP_CHECK(m, sizeof(struct udphdr));
uh = (struct udphdr *) mtodo(m, l3_offset + hlen);
uh->uh_sum = in_pseudo(ip4->ip_src.s_addr,
ip4->ip_dst.s_addr, htons(ip4->ip_p + plen - hlen));
if ((priv->conf->csum_offload & CSUM_UDP) == 0) {
uh->uh_sum = in_cksum_skip(m,
l3_offset + plen, l3_offset + hlen);
if (uh->uh_sum == 0)
uh->uh_sum = 0xffff;
m->m_pkthdr.csum_flags &= ~CSUM_UDP;
}
processed = 1;
}
m->m_pkthdr.csum_flags &= ~CSUM_TCP;
break;
default:
m->m_pkthdr.csum_flags &= ~(CSUM_TCP|CSUM_UDP);
break;
}
m->m_pkthdr.csum_flags &= ~NG_CHECKSUM_CSUM_IPV6;
if (processed)
priv->stats.processed++;
return (0);
}
#endif /* INET */
#ifdef INET6
static int
checksum_ipv6(priv_p priv, struct mbuf *m, int l3_offset)
{
struct ip6_hdr *ip6;
struct ip6_ext *ip6e = NULL;
int pullup_len;
int hlen, plen;
int nxt;
int processed = 0;
pullup_len = l3_offset;
PULLUP_CHECK(m, sizeof(struct ip6_hdr));
ip6 = (struct ip6_hdr *) mtodo(m, l3_offset);
if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION)
return (EOPNOTSUPP);
hlen = sizeof(struct ip6_hdr);
plen = ntohs(ip6->ip6_plen) + hlen;
if (m->m_pkthdr.len < l3_offset + plen)
return (EINVAL);
nxt = ip6->ip6_nxt;
for (;;) {
switch (nxt)
{
case IPPROTO_DSTOPTS:
case IPPROTO_HOPOPTS:
case IPPROTO_ROUTING:
PULLUP_CHECK(m, sizeof(struct ip6_ext));
ip6e = (struct ip6_ext *) mtodo(m, l3_offset + hlen);
nxt = ip6e->ip6e_nxt;
hlen += (ip6e->ip6e_len + 1) << 3;
pullup_len = l3_offset + hlen;
break;
case IPPROTO_AH:
PULLUP_CHECK(m, sizeof(struct ip6_ext));
ip6e = (struct ip6_ext *) mtodo(m, l3_offset + hlen);
nxt = ip6e->ip6e_nxt;
hlen += (ip6e->ip6e_len + 2) << 2;
pullup_len = l3_offset + hlen;
break;
case IPPROTO_FRAGMENT:
/* We can not calculate a checksum fragmented packets */
m->m_pkthdr.csum_flags &= ~(CSUM_TCP_IPV6|CSUM_UDP_IPV6);
return (0);
default:
goto loopend;
}
if (nxt == 0)
return (EINVAL);
}
loopend:
switch (nxt)
{
case IPPROTO_TCP:
if (m->m_pkthdr.csum_flags & CSUM_TCP_IPV6) {
struct tcphdr *th;
PULLUP_CHECK(m, sizeof(struct tcphdr));
th = (struct tcphdr *) mtodo(m, l3_offset + hlen);
th->th_sum = in6_cksum_pseudo(ip6, plen - hlen, nxt, 0);
if ((priv->conf->csum_offload & CSUM_TCP_IPV6) == 0) {
th->th_sum = in_cksum_skip(m, l3_offset + plen, l3_offset + hlen);
m->m_pkthdr.csum_flags &= ~CSUM_TCP_IPV6;
}
processed = 1;
}
m->m_pkthdr.csum_flags &= ~CSUM_UDP_IPV6;
break;
case IPPROTO_UDP:
if (m->m_pkthdr.csum_flags & CSUM_UDP_IPV6) {
struct udphdr *uh;
PULLUP_CHECK(m, sizeof(struct udphdr));
uh = (struct udphdr *) mtodo(m, l3_offset + hlen);
uh->uh_sum = in6_cksum_pseudo(ip6, plen - hlen, nxt, 0);
if ((priv->conf->csum_offload & CSUM_UDP_IPV6) == 0) {
uh->uh_sum = in_cksum_skip(m,
l3_offset + plen, l3_offset + hlen);
if (uh->uh_sum == 0)
uh->uh_sum = 0xffff;
m->m_pkthdr.csum_flags &= ~CSUM_UDP_IPV6;
}
processed = 1;
}
m->m_pkthdr.csum_flags &= ~CSUM_TCP_IPV6;
break;
default:
m->m_pkthdr.csum_flags &= ~(CSUM_TCP_IPV6|CSUM_UDP_IPV6);
break;
}
m->m_pkthdr.csum_flags &= ~NG_CHECKSUM_CSUM_IPV4;
if (processed)
priv->stats.processed++;
return (0);
}
#endif /* INET6 */
#undef PULLUP_CHECK
static int
ng_checksum_rcvdata(hook_p hook, item_p item)
{
const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
struct mbuf *m;
hook_p out;
int error = 0;
priv->stats.received++;
NGI_GET_M(item, m);
#define PULLUP_CHECK(mbuf, length) do { \
pullup_len += length; \
if (((mbuf)->m_pkthdr.len < pullup_len) || \
(pullup_len > MHLEN)) { \
error = EINVAL; \
goto bypass; \
} \
if ((mbuf)->m_len < pullup_len && \
(((mbuf) = m_pullup((mbuf), pullup_len)) == NULL)) { \
error = ENOBUFS; \
goto drop; \
} \
} while (0)
if (!(priv->conf && hook == priv->in && m && (m->m_flags & M_PKTHDR)))
goto bypass;
m->m_pkthdr.csum_flags |= priv->conf->csum_flags;
if (m->m_pkthdr.csum_flags & (NG_CHECKSUM_CSUM_IPV4|NG_CHECKSUM_CSUM_IPV6))
{
struct ether_header *eh;
struct ng_checksum_vlan_header *vh;
int pullup_len = 0;
uint16_t etype;
m = m_unshare(m, M_NOWAIT);
if (m == NULL)
ERROUT(ENOMEM);
switch (priv->dlt)
{
case DLT_EN10MB:
PULLUP_CHECK(m, sizeof(struct ether_header));
eh = mtod(m, struct ether_header *);
etype = ntohs(eh->ether_type);
for (;;) { /* QinQ support */
switch (etype)
{
case 0x8100:
case 0x88A8:
case 0x9100:
PULLUP_CHECK(m, sizeof(struct ng_checksum_vlan_header));
vh = (struct ng_checksum_vlan_header *) mtodo(m,
pullup_len - sizeof(struct ng_checksum_vlan_header));
etype = ntohs(vh->etype);
break;
default:
goto loopend;
}
}
loopend:
#ifdef INET
if (etype == ETHERTYPE_IP &&
(m->m_pkthdr.csum_flags & NG_CHECKSUM_CSUM_IPV4)) {
error = checksum_ipv4(priv, m, pullup_len);
if (error == ENOBUFS)
goto drop;
} else
#endif
#ifdef INET6
if (etype == ETHERTYPE_IPV6 &&
(m->m_pkthdr.csum_flags & NG_CHECKSUM_CSUM_IPV6)) {
error = checksum_ipv6(priv, m, pullup_len);
if (error == ENOBUFS)
goto drop;
} else
#endif
{
m->m_pkthdr.csum_flags &=
~(NG_CHECKSUM_CSUM_IPV4|NG_CHECKSUM_CSUM_IPV6);
}
break;
case DLT_RAW:
#ifdef INET
if (m->m_pkthdr.csum_flags & NG_CHECKSUM_CSUM_IPV4)
{
error = checksum_ipv4(priv, m, pullup_len);
if (error == 0)
goto bypass;
else if (error == ENOBUFS)
goto drop;
}
#endif
#ifdef INET6
if (m->m_pkthdr.csum_flags & NG_CHECKSUM_CSUM_IPV6)
{
error = checksum_ipv6(priv, m, pullup_len);
if (error == 0)
goto bypass;
else if (error == ENOBUFS)
goto drop;
}
#endif
if (error)
m->m_pkthdr.csum_flags &=
~(NG_CHECKSUM_CSUM_IPV4|NG_CHECKSUM_CSUM_IPV6);
break;
default:
ERROUT(EINVAL);
}
}
#undef PULLUP_CHECK
bypass:
out = NULL;
if (hook == priv->in) {
/* return frames on 'in' hook if 'out' not connected */
out = priv->out ? priv->out : priv->in;
} else if (hook == priv->out && priv->in) {
/* pass frames on 'out' hook if 'in' connected */
out = priv->in;
}
if (out == NULL)
ERROUT(0);
NG_FWD_NEW_DATA(error, item, out, m);
return (error);
done:
NG_FREE_M(m);
drop:
NG_FREE_ITEM(item);
priv->stats.dropped++;
return (error);
}
static int
ng_checksum_shutdown(node_p node)
{
const priv_p priv = NG_NODE_PRIVATE(node);
NG_NODE_SET_PRIVATE(node, NULL);
NG_NODE_UNREF(node);
if (priv->conf)
free(priv->conf, M_NETGRAPH);
free(priv, M_NETGRAPH);
return (0);
}
static int
ng_checksum_disconnect(hook_p hook)
{
priv_p priv;
priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
if (hook == priv->in)
priv->in = NULL;
if (hook == priv->out)
priv->out = NULL;
if (NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0 &&
NG_NODE_IS_VALID(NG_HOOK_NODE(hook))) /* already shutting down? */
ng_rmnode_self(NG_HOOK_NODE(hook));
return (0);
}