picnoir/Systemd
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity
Systemd/src/libsystemd/sd-rtnl/rtnl-message.c
Susant Sahani 9a6704a81f sd-rtnl: add support for tunnel attributes 
Added support for tunneling netlink attrributes (ipip, gre, sit).
These works with kernel module ipip, gre and sit . The test cases are
moved to a separate file and manual test as well because they require
respective kernel modules as well.
2014-03-25 14:44:33 +01:00

1312 lines
41 KiB
C
Raw Blame History

/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2013 Tom Gundersen <teg@jklm.no>
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <netinet/in.h>
#include <netinet/ether.h>
#include <stdbool.h>
#include <unistd.h>
#include <linux/veth.h>
#include <linux/if.h>
#include <linux/ip.h>
#include <linux/if_tunnel.h>
#include <linux/if_bridge.h>
#include "util.h"
#include "refcnt.h"
#include "missing.h"
#include "sd-rtnl.h"
#include "rtnl-util.h"
#include "rtnl-internal.h"
#define GET_CONTAINER(m, i) ((i) < (m)->n_containers ? (struct rtattr*)((uint8_t*)(m)->hdr + (m)->container_offsets[i]) : NULL)
#define PUSH_CONTAINER(m, new) (m)->container_offsets[(m)->n_containers ++] = (uint8_t*)(new) - (uint8_t*)(m)->hdr;
int message_new(sd_rtnl *rtnl, sd_rtnl_message **ret, size_t initial_size) {
sd_rtnl_message *m;
assert_return(ret, -EINVAL);
assert_return(initial_size >= sizeof(struct nlmsghdr), -EINVAL);
m = new0(sd_rtnl_message, 1);
if (!m)
return -ENOMEM;
m->hdr = malloc0(initial_size);
if (!m->hdr) {
free(m);
return -ENOMEM;
}
m->n_ref = REFCNT_INIT;
m->hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
m->sealed = false;
if (rtnl)
m->rtnl = sd_rtnl_ref(rtnl);
*ret = m;
return 0;
}
int sd_rtnl_message_route_set_dst_prefixlen(sd_rtnl_message *m, unsigned char prefixlen) {
struct rtmsg *rtm;
assert_return(m, -EINVAL);
assert_return(m->hdr, -EINVAL);
assert_return(rtnl_message_type_is_route(m->hdr->nlmsg_type), -EINVAL);
rtm = NLMSG_DATA(m->hdr);
if ((rtm->rtm_family == AF_INET && prefixlen > 32) ||
(rtm->rtm_family == AF_INET6 && prefixlen > 128))
return -ERANGE;
rtm->rtm_dst_len = prefixlen;
return 0;
}
int sd_rtnl_message_route_set_scope(sd_rtnl_message *m, unsigned char scope) {
struct rtmsg *rtm;
assert_return(m, -EINVAL);
assert_return(m->hdr, -EINVAL);
assert_return(rtnl_message_type_is_route(m->hdr->nlmsg_type), -EINVAL);
rtm = NLMSG_DATA(m->hdr);
rtm->rtm_scope = scope;
return 0;
}
int sd_rtnl_message_new_route(sd_rtnl *rtnl, sd_rtnl_message **ret,
uint16_t nlmsg_type, unsigned char rtm_family) {
struct rtmsg *rtm;
int r;
assert_return(rtnl_message_type_is_route(nlmsg_type), -EINVAL);
assert_return(rtm_family == AF_INET || rtm_family == AF_INET6, -EINVAL);
assert_return(ret, -EINVAL);
r = message_new(rtnl, ret, NLMSG_SPACE(sizeof(struct rtmsg)));
if (r < 0)
return r;
(*ret)->hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
(*ret)->hdr->nlmsg_type = nlmsg_type;
if (nlmsg_type == RTM_NEWROUTE)
(*ret)->hdr->nlmsg_flags |= NLM_F_CREATE | NLM_F_EXCL;
rtm = NLMSG_DATA((*ret)->hdr);
rtm->rtm_family = rtm_family;
rtm->rtm_scope = RT_SCOPE_UNIVERSE;
rtm->rtm_type = RTN_UNICAST;
rtm->rtm_table = RT_TABLE_MAIN;
rtm->rtm_protocol = RTPROT_BOOT;
return 0;
}
int sd_rtnl_message_link_set_flags(sd_rtnl_message *m, unsigned flags, unsigned change) {
struct ifinfomsg *ifi;
assert_return(m, -EINVAL);
assert_return(m->hdr, -EINVAL);
assert_return(rtnl_message_type_is_link(m->hdr->nlmsg_type), -EINVAL);
assert_return(change, -EINVAL);
ifi = NLMSG_DATA(m->hdr);
ifi->ifi_flags = flags;
ifi->ifi_change = change;
return 0;
}
int sd_rtnl_message_link_set_type(sd_rtnl_message *m, unsigned type) {
struct ifinfomsg *ifi;
assert_return(m, -EINVAL);
assert_return(m->hdr, -EINVAL);
assert_return(rtnl_message_type_is_link(m->hdr->nlmsg_type), -EINVAL);
ifi = NLMSG_DATA(m->hdr);
ifi->ifi_type = type;
return 0;
}
int sd_rtnl_message_new_link(sd_rtnl *rtnl, sd_rtnl_message **ret,
uint16_t nlmsg_type, int index) {
struct ifinfomsg *ifi;
int r;
assert_return(rtnl_message_type_is_link(nlmsg_type), -EINVAL);
assert_return(nlmsg_type != RTM_DELLINK || index > 0, -EINVAL);
assert_return(ret, -EINVAL);
r = message_new(rtnl, ret, NLMSG_SPACE(sizeof(struct ifinfomsg)));
if (r < 0)
return r;
(*ret)->hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
(*ret)->hdr->nlmsg_type = nlmsg_type;
if (nlmsg_type == RTM_NEWLINK)
(*ret)->hdr->nlmsg_flags |= NLM_F_CREATE | NLM_F_EXCL;
ifi = NLMSG_DATA((*ret)->hdr);
ifi->ifi_family = AF_UNSPEC;
ifi->ifi_index = index;
return 0;
}
int sd_rtnl_message_addr_set_prefixlen(sd_rtnl_message *m, unsigned char prefixlen) {
struct ifaddrmsg *ifa;
assert_return(m, -EINVAL);
assert_return(m->hdr, -EINVAL);
assert_return(rtnl_message_type_is_addr(m->hdr->nlmsg_type), -EINVAL);
ifa = NLMSG_DATA(m->hdr);
if ((ifa->ifa_family == AF_INET && prefixlen > 32) ||
(ifa->ifa_family == AF_INET6 && prefixlen > 128))
return -ERANGE;
ifa->ifa_prefixlen = prefixlen;
return 0;
}
int sd_rtnl_message_addr_set_flags(sd_rtnl_message *m, unsigned char flags) {
struct ifaddrmsg *ifa;
assert_return(m, -EINVAL);
assert_return(m->hdr, -EINVAL);
assert_return(rtnl_message_type_is_addr(m->hdr->nlmsg_type), -EINVAL);
ifa = NLMSG_DATA(m->hdr);
ifa->ifa_flags = flags;
return 0;
}
int sd_rtnl_message_addr_set_scope(sd_rtnl_message *m, unsigned char scope) {
struct ifaddrmsg *ifa;
assert_return(m, -EINVAL);
assert_return(m->hdr, -EINVAL);
assert_return(rtnl_message_type_is_addr(m->hdr->nlmsg_type), -EINVAL);
ifa = NLMSG_DATA(m->hdr);
ifa->ifa_scope = scope;
return 0;
}
int sd_rtnl_message_new_addr(sd_rtnl *rtnl, sd_rtnl_message **ret,
uint16_t nlmsg_type, int index,
unsigned char family) {
struct ifaddrmsg *ifa;
int r;
assert_return(rtnl_message_type_is_addr(nlmsg_type), -EINVAL);
assert_return(index > 0, -EINVAL);
assert_return(family == AF_INET || family == AF_INET6, -EINVAL);
assert_return(ret, -EINVAL);
r = message_new(rtnl, ret, NLMSG_SPACE(sizeof(struct ifaddrmsg)));
if (r < 0)
return r;
(*ret)->hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg));
(*ret)->hdr->nlmsg_type = nlmsg_type;
if (nlmsg_type == RTM_GETADDR && family == AF_INET)
(*ret)->hdr->nlmsg_flags |= NLM_F_DUMP;
ifa = NLMSG_DATA((*ret)->hdr);
ifa->ifa_index = index;
ifa->ifa_family = family;
if (family == AF_INET)
ifa->ifa_prefixlen = 32;
else if (family == AF_INET6)
ifa->ifa_prefixlen = 128;
return 0;
}
sd_rtnl_message *sd_rtnl_message_ref(sd_rtnl_message *m) {
if (m)
assert_se(REFCNT_INC(m->n_ref) >= 2);
return m;
}
sd_rtnl_message *sd_rtnl_message_unref(sd_rtnl_message *m) {
if (m && REFCNT_DEC(m->n_ref) <= 0) {
unsigned i;
sd_rtnl_unref(m->rtnl);
free(m->hdr);
for (i = 0; i < m->n_containers; i++)
free(m->rta_offset_tb[i]);
free(m);
}
return NULL;
}
int sd_rtnl_message_get_type(sd_rtnl_message *m, uint16_t *type) {
assert_return(m, -EINVAL);
assert_return(type, -EINVAL);
*type = m->hdr->nlmsg_type;
return 0;
}
int sd_rtnl_message_is_broadcast(sd_rtnl_message *m) {
assert_return(m, -EINVAL);
return !m->hdr->nlmsg_pid;
}
int sd_rtnl_message_link_get_ifindex(sd_rtnl_message *m, int *ifindex) {
struct ifinfomsg *ifi;
assert_return(m, -EINVAL);
assert_return(m->hdr, -EINVAL);
assert_return(rtnl_message_type_is_link(m->hdr->nlmsg_type), -EINVAL);
assert_return(ifindex, -EINVAL);
ifi = NLMSG_DATA(m->hdr);
*ifindex = ifi->ifi_index;
return 0;
}
int sd_rtnl_message_link_get_flags(sd_rtnl_message *m, unsigned *flags) {
struct ifinfomsg *ifi;
assert_return(m, -EINVAL);
assert_return(m->hdr, -EINVAL);
assert_return(rtnl_message_type_is_link(m->hdr->nlmsg_type), -EINVAL);
assert_return(flags, -EINVAL);
ifi = NLMSG_DATA(m->hdr);
*flags = ifi->ifi_flags;
return 0;
}
/* If successful the updated message will be correctly aligned, if
unsuccessful the old message is untouched. */
static int add_rtattr(sd_rtnl_message *m, unsigned short type, const void *data, size_t data_length) {
uint32_t rta_length, message_length;
struct nlmsghdr *new_hdr;
struct rtattr *rta;
char *padding;
unsigned i;
assert(m);
assert(m->hdr);
assert(!m->sealed);
assert(NLMSG_ALIGN(m->hdr->nlmsg_len) == m->hdr->nlmsg_len);
assert(!data || data_length > 0);
assert(data || m->n_containers < RTNL_CONTAINER_DEPTH);
/* get the size of the new rta attribute (with padding at the end) */
rta_length = RTA_LENGTH(data_length);
/* get the new message size (with padding at the end) */
message_length = m->hdr->nlmsg_len + RTA_ALIGN(rta_length);
/* realloc to fit the new attribute */
new_hdr = realloc(m->hdr, message_length);
if (!new_hdr)
return -ENOMEM;
m->hdr = new_hdr;
/* get pointer to the attribute we are about to add */
rta = (struct rtattr *) ((uint8_t *) m->hdr + m->hdr->nlmsg_len);
/* if we are inside containers, extend them */
for (i = 0; i < m->n_containers; i++)
GET_CONTAINER(m, i)->rta_len += message_length - m->hdr->nlmsg_len;
/* fill in the attribute */
rta->rta_type = type;
rta->rta_len = rta_length;
if (!data) {
/* this is the start of a new container */
m->container_offsets[m->n_containers ++] = m->hdr->nlmsg_len;
} else {
/* we don't deal with the case where the user lies about the type
* and gives us too little data (so don't do that)
*/
padding = mempcpy(RTA_DATA(rta), data, data_length);
/* make sure also the padding at the end of the message is initialized */
memzero(padding,
(uint8_t *) m->hdr + message_length - (uint8_t *) padding);
}
/* update message size */
m->hdr->nlmsg_len = message_length;
return 0;
}
int sd_rtnl_message_append_string(sd_rtnl_message *m, unsigned short type, const char *data) {
uint16_t rtm_type;
int r;
assert_return(m, -EINVAL);
assert_return(!m->sealed, -EPERM);
assert_return(data, -EINVAL);
r = sd_rtnl_message_get_type(m, &rtm_type);
if (r < 0)
return r;
/* check that the type is correct */
switch (rtm_type) {
case RTM_NEWLINK:
case RTM_SETLINK:
case RTM_GETLINK:
case RTM_DELLINK:
if (m->n_containers == 1) {
if (GET_CONTAINER(m, 0)->rta_type != IFLA_LINKINFO ||
type != IFLA_INFO_KIND)
return -ENOTSUP;
} else {
switch (type) {
case IFLA_IFNAME:
case IFLA_IFALIAS:
case IFLA_QDISC:
break;
default:
return -ENOTSUP;
}
}
break;
case RTM_NEWADDR:
case RTM_GETADDR:
case RTM_DELADDR:
if (type != IFA_LABEL)
return -ENOTSUP;
break;
default:
return -ENOTSUP;
}
r = add_rtattr(m, type, data, strlen(data) + 1);
if (r < 0)
return r;
return 0;
}
int sd_rtnl_message_append_u8(sd_rtnl_message *m, unsigned short type, uint8_t data) {
uint16_t rtm_type;
int r;
assert_return(m, -EINVAL);
assert_return(!m->sealed, -EPERM);
r = sd_rtnl_message_get_type(m, &rtm_type);
if (r < 0)
return r;
switch (rtm_type) {
case RTM_NEWLINK:
case RTM_SETLINK:
case RTM_GETLINK:
case RTM_DELLINK:
switch (type) {
case IFLA_CARRIER:
case IFLA_OPERSTATE:
case IFLA_LINKMODE:
case IFLA_IPTUN_TTL:
case IFLA_IPTUN_TOS:
case IFLA_IPTUN_PROTO:
case IFLA_IPTUN_PMTUDISC:
case IFLA_IPTUN_ENCAP_LIMIT:
case IFLA_GRE_TTL:
break;
default:
return -ENOTSUP;
}
break;
default:
return -ENOTSUP;
}
r = add_rtattr(m, type, &data, sizeof(uint8_t));
if (r < 0)
return r;
return 0;
}
int sd_rtnl_message_append_u16(sd_rtnl_message *m, unsigned short type, uint16_t data) {
uint16_t rtm_type;
int r;
assert_return(m, -EINVAL);
assert_return(!m->sealed, -EPERM);
r = sd_rtnl_message_get_type(m, &rtm_type);
if (r < 0)
return r;
/* check that the type is correct */
switch (rtm_type) {
case RTM_NEWLINK:
case RTM_SETLINK:
case RTM_GETLINK:
case RTM_DELLINK:
if (m->n_containers == 2 &&
GET_CONTAINER(m, 0)->rta_type == IFLA_LINKINFO &&
GET_CONTAINER(m, 1)->rta_type == IFLA_INFO_DATA) {
switch (type) {
case IFLA_VLAN_ID:
case IFLA_IPTUN_FLAGS:
case IFLA_GRE_IFLAGS:
case IFLA_GRE_OFLAGS:
case IFLA_IPTUN_6RD_PREFIXLEN:
case IFLA_IPTUN_6RD_RELAY_PREFIXLEN:
break;
default:
return -ENOTSUP;
}
} else
return -ENOTSUP;
break;
default:
return -ENOTSUP;
}
r = add_rtattr(m, type, &data, sizeof(uint16_t));
if (r < 0)
return r;
return 0;
}
int sd_rtnl_message_append_u32(sd_rtnl_message *m, unsigned short type, uint32_t data) {
uint16_t rtm_type;
int r;
assert_return(m, -EINVAL);
assert_return(!m->sealed, -EPERM);
r = sd_rtnl_message_get_type(m, &rtm_type);
if (r < 0)
return r;
/* check that the type is correct */
switch (rtm_type) {
case RTM_NEWLINK:
case RTM_SETLINK:
case RTM_GETLINK:
case RTM_DELLINK:
switch (type) {
case IFLA_MASTER:
case IFLA_MTU:
case IFLA_LINK:
case IFLA_GROUP:
case IFLA_TXQLEN:
case IFLA_WEIGHT:
case IFLA_NET_NS_FD:
case IFLA_NET_NS_PID:
case IFLA_PROMISCUITY:
case IFLA_NUM_TX_QUEUES:
case IFLA_NUM_RX_QUEUES:
case IFLA_IPTUN_LOCAL:
case IFLA_IPTUN_REMOTE:
case IFLA_MACVLAN_MODE:
case IFLA_IPTUN_FLAGS:
case IFLA_IPTUN_FLOWINFO:
case IFLA_GRE_FLOWINFO:
break;
default:
return -ENOTSUP;
}
break;
case RTM_NEWROUTE:
case RTM_GETROUTE:
case RTM_DELROUTE:
switch (type) {
case RTA_TABLE:
case RTA_PRIORITY:
case RTA_IIF:
case RTA_OIF:
case RTA_MARK:
break;
default:
return -ENOTSUP;
}
break;
default:
return -ENOTSUP;
}
r = add_rtattr(m, type, &data, sizeof(uint32_t));
if (r < 0)
return r;
return 0;
}
int sd_rtnl_message_append_in_addr(sd_rtnl_message *m, unsigned short type, const struct in_addr *data) {
struct ifaddrmsg *ifa;
struct rtmsg *rtm;
uint16_t rtm_type;
int r;
assert_return(m, -EINVAL);
assert_return(!m->sealed, -EPERM);
assert_return(data, -EINVAL);
r = sd_rtnl_message_get_type(m, &rtm_type);
if (r < 0)
return r;
/* check that the type is correct */
switch (rtm_type) {
case RTM_NEWADDR:
case RTM_GETADDR:
case RTM_DELADDR:
switch (type) {
case IFA_ADDRESS:
case IFA_LOCAL:
case IFA_BROADCAST:
case IFA_ANYCAST:
case IFLA_GRE_LOCAL:
case IFLA_GRE_REMOTE:
ifa = NLMSG_DATA(m->hdr);
if (ifa->ifa_family != AF_INET)
return -EINVAL;
break;
default:
return -ENOTSUP;
}
break;
case RTM_NEWROUTE:
case RTM_GETROUTE:
case RTM_DELROUTE:
switch (type) {
case RTA_DST:
case RTA_SRC:
case RTA_GATEWAY:
rtm = NLMSG_DATA(m->hdr);
if (rtm->rtm_family != AF_INET)
return -EINVAL;
break;
default:
return -ENOTSUP;
}
break;
default:
return -ENOTSUP;
}
r = add_rtattr(m, type, data, sizeof(struct in_addr));
if (r < 0)
return r;
return 0;
}
int sd_rtnl_message_append_in6_addr(sd_rtnl_message *m, unsigned short type, const struct in6_addr *data) {
struct ifaddrmsg *ifa;
struct rtmsg *rtm;
uint16_t rtm_type;
int r;
assert_return(m, -EINVAL);
assert_return(!m->sealed, -EPERM);
assert_return(data, -EINVAL);
r = sd_rtnl_message_get_type(m, &rtm_type);
if (r < 0)
return r;
/* check that the type is correct */
switch (rtm_type) {
case RTM_NEWADDR:
case RTM_GETADDR:
case RTM_DELADDR:
switch (type) {
case IFA_ADDRESS:
case IFA_LOCAL:
case IFA_BROADCAST:
case IFA_ANYCAST:
case IFLA_GRE_LOCAL:
case IFLA_GRE_REMOTE:
case IFLA_IPTUN_6RD_PREFIX:
ifa = NLMSG_DATA(m->hdr);
if (ifa->ifa_family != AF_INET6)
return -EINVAL;
break;
default:
return -ENOTSUP;
}
break;
case RTM_NEWROUTE:
case RTM_GETROUTE:
case RTM_DELROUTE:
switch (type) {
case RTA_DST:
case RTA_SRC:
case RTA_GATEWAY:
rtm = NLMSG_DATA(m->hdr);
if (rtm->rtm_family != AF_INET6)
return -EINVAL;
break;
default:
return -ENOTSUP;
}
default:
return -ENOTSUP;
}
r = add_rtattr(m, type, data, sizeof(struct in6_addr));
if (r < 0)
return r;
return 0;
}
int sd_rtnl_message_append_ether_addr(sd_rtnl_message *m, unsigned short type, const struct ether_addr *data) {
uint16_t rtm_type;
int r;
assert_return(m, -EINVAL);
assert_return(!m->sealed, -EPERM);
assert_return(data, -EINVAL);
sd_rtnl_message_get_type(m, &rtm_type);
switch (rtm_type) {
case RTM_NEWLINK:
case RTM_SETLINK:
case RTM_DELLINK:
case RTM_GETLINK:
switch (type) {
case IFLA_ADDRESS:
case IFLA_BROADCAST:
break;
default:
return -ENOTSUP;
}
break;
default:
return -ENOTSUP;
}
r = add_rtattr(m, type, data, ETH_ALEN);
if (r < 0)
return r;
return 0;
}
int sd_rtnl_message_open_container(sd_rtnl_message *m, unsigned short type) {
uint16_t rtm_type;
assert_return(m, -EINVAL);
assert_return(!m->sealed, -EPERM);
sd_rtnl_message_get_type(m, &rtm_type);
if (rtnl_message_type_is_link(rtm_type)) {
if ((type == IFLA_LINKINFO && m->n_containers == 0) ||
(type == IFLA_INFO_DATA && m->n_containers == 1 &&
GET_CONTAINER(m, 0)->rta_type == IFLA_LINKINFO))
return add_rtattr(m, type, NULL, 0);
else if (type == VETH_INFO_PEER && m->n_containers == 2 &&
GET_CONTAINER(m, 1)->rta_type == IFLA_INFO_DATA &&
GET_CONTAINER(m, 0)->rta_type == IFLA_LINKINFO)
return add_rtattr(m, type, NULL, sizeof(struct ifinfomsg));
}
return -ENOTSUP;
}
int sd_rtnl_message_close_container(sd_rtnl_message *m) {
assert_return(m, -EINVAL);
assert_return(!m->sealed, -EPERM);
assert_return(m->n_containers > 0, -EINVAL);
m->n_containers --;
return 0;
}
int rtnl_message_read_internal(sd_rtnl_message *m, unsigned short type, void **data) {
struct rtattr *rta;
assert_return(m, -EINVAL);
assert_return(m->sealed, -EPERM);
assert_return(data, -EINVAL);
assert_return(m->rta_offset_tb[m->n_containers], -EINVAL);
assert_return(type < m->rta_tb_size[m->n_containers], -EINVAL);
if(!m->rta_offset_tb[m->n_containers][type])
return -ENODATA;
rta = (struct rtattr*)((uint8_t *) m->hdr + m->rta_offset_tb[m->n_containers][type]);
*data = RTA_DATA(rta);
return RTA_PAYLOAD(rta);
}
int sd_rtnl_message_read_string(sd_rtnl_message *m, unsigned short type, char **data) {
int r;
void *attr_data;
assert_return(data, -EINVAL);
r = rtnl_message_read_internal(m, type, &attr_data);
if (r < 0)
return r;
else if (strnlen(attr_data, r) >= (size_t) r)
return -EIO;
*data = (char *) attr_data;
return 0;
}
int sd_rtnl_message_read_u8(sd_rtnl_message *m, unsigned short type, uint8_t *data) {
int r;
void *attr_data;
assert_return(data, -EINVAL);
r = rtnl_message_read_internal(m, type, &attr_data);
if (r < 0)
return r;
else if ((size_t) r < sizeof(uint8_t))
return -EIO;
*data = *(uint8_t *) attr_data;
return 0;
}
int sd_rtnl_message_read_u16(sd_rtnl_message *m, unsigned short type, uint16_t *data) {
int r;
void *attr_data;
assert_return(data, -EINVAL);
r = rtnl_message_read_internal(m, type, &attr_data);
if (r < 0)
return r;
else if ((size_t) r < sizeof(uint16_t))
return -EIO;
*data = *(uint16_t *) attr_data;
return 0;
}
int sd_rtnl_message_read_u32(sd_rtnl_message *m, unsigned short type, uint32_t *data) {
int r;
void *attr_data;
assert_return(data, -EINVAL);
r = rtnl_message_read_internal(m, type, &attr_data);
if (r < 0)
return r;
else if ((size_t)r < sizeof(uint32_t))
return -EIO;
*data = *(uint32_t *) attr_data;
return 0;
}
int sd_rtnl_message_read_ether_addr(sd_rtnl_message *m, unsigned short type, struct ether_addr *data) {
int r;
void *attr_data;
assert_return(data, -EINVAL);
r = rtnl_message_read_internal(m, type, &attr_data);
if (r < 0)
return r;
else if ((size_t)r < sizeof(struct ether_addr))
return -EIO;
memcpy(data, attr_data, sizeof(struct ether_addr));
return 0;
}
int sd_rtnl_message_read_in_addr(sd_rtnl_message *m, unsigned short type, struct in_addr *data) {
int r;
void *attr_data;
assert_return(data, -EINVAL);
r = rtnl_message_read_internal(m, type, &attr_data);
if (r < 0)
return r;
else if ((size_t)r < sizeof(struct in_addr))
return -EIO;
memcpy(data, attr_data, sizeof(struct in_addr));
return 0;
}
int sd_rtnl_message_read_in6_addr(sd_rtnl_message *m, unsigned short type, struct in6_addr *data) {
int r;
void *attr_data;
assert_return(data, -EINVAL);
r = rtnl_message_read_internal(m, type, &attr_data);
if (r < 0)
return r;
else if ((size_t)r < sizeof(struct in6_addr))
return -EIO;
memcpy(data, attr_data, sizeof(struct in6_addr));
return 0;
}
int sd_rtnl_message_enter_container(sd_rtnl_message *m, unsigned short type) {
uint16_t rtm_type;
unsigned short parent_type;
void *container;
size_t container_length;
int max, r;
assert_return(m, -EINVAL);
assert_return(m->n_containers < RTNL_CONTAINER_DEPTH, -EINVAL);
r = rtnl_message_read_internal(m, type, &container);
if (r < 0)
return r;
else
container_length = r;
r = sd_rtnl_message_get_type(m, &rtm_type);
if (r < 0)
return r;
if (rtnl_message_type_is_link(rtm_type)) {
switch (m->n_containers) {
case 0:
switch (type) {
case IFLA_LINKINFO:
max = IFLA_INFO_MAX;
break;
default:
return -ENOTSUP;
}
break;
case 1:
parent_type = GET_CONTAINER(m, 0)->rta_type;
switch (parent_type) {
case IFLA_LINKINFO:
switch (type) {
case IFLA_INFO_DATA: {
char *kind;
r = sd_rtnl_message_read_string(m, IFLA_INFO_KIND, &kind);
if (r < 0)
return r;
if (streq(kind, "vlan")) {
max = IFLA_VLAN_MAX;
} else if (streq(kind, "bridge")) {
max = IFLA_BRIDGE_MAX;
} else if (streq(kind, "veth")) {
max = VETH_INFO_MAX;
container = IFLA_RTA(container);
} else
return -ENOTSUP;
break;
}
default:
return -ENOTSUP;
}
break;
default:
return -ENOTSUP;
}
break;
default:
return -ENOTSUP;
}
} else
return -ENOTSUP;
r = rtnl_message_parse(m,
&m->rta_offset_tb[m->n_containers + 1],
&m->rta_tb_size[m->n_containers + 1],
max,
container,
container_length);
if (r < 0)
return r;
m->n_containers ++;
return 0;
}
int sd_rtnl_message_exit_container(sd_rtnl_message *m) {
assert_return(m, -EINVAL);
assert_return(m->sealed, -EINVAL);
assert_return(m->n_containers > 0, -EINVAL);
free(m->rta_offset_tb[m->n_containers]);
m->rta_offset_tb[m->n_containers] = NULL;
m->n_containers --;
return 0;
}
uint32_t rtnl_message_get_serial(sd_rtnl_message *m) {
assert(m);
assert(m->hdr);
return m->hdr->nlmsg_seq;
}
int sd_rtnl_message_get_errno(sd_rtnl_message *m) {
struct nlmsgerr *err;
assert_return(m, -EINVAL);
assert_return(m->hdr, -EINVAL);
if (m->hdr->nlmsg_type != NLMSG_ERROR)
return 0;
err = NLMSG_DATA(m->hdr);
return err->error;
}
static int message_receive_need(sd_rtnl *rtnl, size_t *need) {
assert(rtnl);
assert(need);
/* ioctl(rtnl->fd, FIONREAD, &need)
Does not appear to work on netlink sockets. libnl uses
MSG_PEEK instead. I don't know if that is worth the
extra roundtrip.
For now we simply use the maximum message size the kernel
may use (NLMSG_GOODSIZE), and then realloc to the actual
size after reading the message (hence avoiding huge memory
usage in case many small messages are kept around) */
*need = page_size();
if (*need > 8192UL)
*need = 8192UL;
return 0;
}
int rtnl_message_parse(sd_rtnl_message *m,
size_t **rta_offset_tb,
unsigned short *rta_tb_size,
int max,
struct rtattr *rta,
unsigned int rt_len) {
unsigned short type;
size_t *tb;
tb = (size_t *) new0(size_t *, max);
if(!tb)
return -ENOMEM;
*rta_tb_size = max;
for (; RTA_OK(rta, rt_len); rta = RTA_NEXT(rta, rt_len)) {
type = rta->rta_type;
if (type > max) {
log_debug("rtnl: message parse - ignore out of range attribute type");
continue;
}
if (tb[type])
log_debug("rtnl: message parse - overwriting repeated attribute");
tb[type] = (uint8_t *) rta - (uint8_t *) m->hdr;
}
*rta_offset_tb = tb;
return 0;
}
/* returns the number of bytes sent, or a negative error code */
int socket_write_message(sd_rtnl *nl, sd_rtnl_message *m) {
union {
struct sockaddr sa;
struct sockaddr_nl nl;
} addr = {
.nl.nl_family = AF_NETLINK,
};
ssize_t k;
assert(nl);
assert(m);
assert(m->hdr);
k = sendto(nl->fd, m->hdr, m->hdr->nlmsg_len,
0, &addr.sa, sizeof(addr));
if (k < 0)
return (errno == EAGAIN) ? 0 : -errno;
return k;
}
/* On success, the number of bytes received is returned and *ret points to the received message
* which has a valid header and the correct size.
* If nothing useful was received 0 is returned.
* On failure, a negative error code is returned.
*/
int socket_read_message(sd_rtnl *nl, sd_rtnl_message **ret) {
_cleanup_rtnl_message_unref_ sd_rtnl_message *m = NULL;
struct nlmsghdr *new_hdr;
union {
struct sockaddr sa;
struct sockaddr_nl nl;
} addr;
socklen_t addr_len;
size_t need, len;
int r;
assert(nl);
assert(ret);
r = message_receive_need(nl, &need);
if (r < 0)
return r;
r = message_new(nl, &m, need);
if (r < 0)
return r;
addr_len = sizeof(addr);
r = recvfrom(nl->fd, m->hdr, need,
0, &addr.sa, &addr_len);
if (r < 0)
return (errno == EAGAIN) ? 0 : -errno; /* no data */
else if (r == 0)
return -ECONNRESET; /* connection was closed by the kernel */
else if (addr_len != sizeof(addr.nl) ||
addr.nl.nl_family != AF_NETLINK)
return -EIO; /* not a netlink message */
else if (addr.nl.nl_pid != 0)
return 0; /* not from the kernel */
else if ((size_t) r < sizeof(struct nlmsghdr) ||
(size_t) r < m->hdr->nlmsg_len)
return -EIO; /* too small (we do accept too big though) */
else if (m->hdr->nlmsg_pid && m->hdr->nlmsg_pid != nl->sockaddr.nl.nl_pid)
return 0; /* not broadcast and not for us */
else
len = (size_t) r;
/* check that the size matches the message type */
switch (m->hdr->nlmsg_type) {
case NLMSG_ERROR:
if (len < NLMSG_LENGTH(sizeof(struct nlmsgerr)))
return -EIO;
break;
case RTM_NEWLINK:
case RTM_SETLINK:
case RTM_DELLINK:
case RTM_GETLINK:
if (len < NLMSG_LENGTH(sizeof(struct ifinfomsg)))
return -EIO;
break;
case RTM_NEWADDR:
case RTM_DELADDR:
case RTM_GETADDR:
if (len < NLMSG_LENGTH(sizeof(struct ifaddrmsg)))
return -EIO;
break;
case RTM_NEWROUTE:
case RTM_DELROUTE:
case RTM_GETROUTE:
if (len < NLMSG_LENGTH(sizeof(struct rtmsg)))
return -EIO;
break;
case NLMSG_NOOP:
return 0;
default:
log_debug("sd-rtnl: ignored message with unknown type");
return 0;
}
/* we probably allocated way too much memory, give it back */
new_hdr = realloc(m->hdr, len);
if (!new_hdr)
return -ENOMEM;
m->hdr = new_hdr;
/* seal and parse the top-level message */
r = sd_rtnl_message_rewind(m);
if (r < 0)
return r;
*ret = m;
m = NULL;
return len;
}
int sd_rtnl_message_rewind(sd_rtnl_message *m) {
struct ifinfomsg *ifi;
struct ifaddrmsg *ifa;
struct rtmsg *rtm;
unsigned i;
int r;
assert_return(m, -EINVAL);
assert_return(m->hdr, -EINVAL);
/* don't allow appending to message once parsed */
if (!m->sealed)
rtnl_message_seal(m);
for (i = 1; i <= m->n_containers; i++) {
free(m->rta_offset_tb[i]);
m->rta_offset_tb[i] = NULL;
m->rta_tb_size[i] = 0;
}
m->n_containers = 0;
if (m->rta_offset_tb[0]) {
/* top-level attributes have already been parsed */
return 0;
}
/* parse top-level attributes */
switch(m->hdr->nlmsg_type) {
case NLMSG_NOOP:
case NLMSG_ERROR:
break;
case RTM_NEWLINK:
case RTM_SETLINK:
case RTM_GETLINK:
case RTM_DELLINK:
ifi = NLMSG_DATA(m->hdr);
r = rtnl_message_parse(m,
&m->rta_offset_tb[0],
&m->rta_tb_size[0],
IFLA_MAX,
IFLA_RTA(ifi),
IFLA_PAYLOAD(m->hdr));
if (r < 0)
return r;
break;
case RTM_NEWADDR:
case RTM_GETADDR:
case RTM_DELADDR:
ifa = NLMSG_DATA(m->hdr);
r = rtnl_message_parse(m,
&m->rta_offset_tb[0],
&m->rta_tb_size[0],
IFA_MAX,
IFA_RTA(ifa),
IFA_PAYLOAD(m->hdr));
if (r < 0)
return r;
break;
case RTM_NEWROUTE:
case RTM_GETROUTE:
case RTM_DELROUTE:
rtm = NLMSG_DATA(m->hdr);
r = rtnl_message_parse(m,
&m->rta_offset_tb[0],
&m->rta_tb_size[0],
RTA_MAX,
RTM_RTA(rtm),
RTM_PAYLOAD(m->hdr));
break;
default:
return -ENOTSUP;
}
return 0;
}
void rtnl_message_seal(sd_rtnl_message *m) {
assert(m);
assert(!m->sealed);
m->sealed = true;
}
Reference in a new issue View git blame Copy permalink