Add a perform_ip_subnet_bcast() function that uses Linux netlink sockets
to set the interface ip, subnet, and broadcast address simultaneously. The advantage of this approach is that a single netlink notification will be sent rather than multiple messages as the ip, subnet, and broadcast address are set one at a time. Currently this function is not used, as it will require a wire format change that will be introduced in a subsequent commit.
This commit is contained in:
Nicholas J. Kain
parent
81a9fe1c8e
commit
06b65de08c
188
ifchd/linux.c
188
ifchd/linux.c
|
|
@ -40,6 +40,8 @@
|
|||
#include <net/route.h>
|
||||
#include <net/if.h>
|
||||
#include <netpacket/packet.h>
|
||||
#include <linux/netlink.h>
|
||||
#include <linux/rtnetlink.h>
|
||||
#include <pwd.h>
|
||||
#include <grp.h>
|
||||
|
||||
|
|
@ -151,6 +153,192 @@ static int set_if_flag(struct ifchd_client *cl, short flag)
|
|||
return ret;
|
||||
}
|
||||
|
||||
#define NLMSG_TAIL(nmsg) \
|
||||
((struct rtattr *) (((uint8_t*) (nmsg)) + \
|
||||
NLMSG_ALIGN((nmsg)->nlmsg_len)))
|
||||
|
||||
static int add_rtattr(struct nlmsghdr *n, size_t max_length, int type,
|
||||
const void *data, size_t data_length)
|
||||
{
|
||||
size_t length;
|
||||
struct rtattr *rta;
|
||||
|
||||
length = RTA_LENGTH(data_length);
|
||||
|
||||
if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(length) > max_length)
|
||||
return -E2BIG;
|
||||
|
||||
rta = NLMSG_TAIL(n);
|
||||
rta->rta_type = type;
|
||||
rta->rta_len = length;
|
||||
memcpy(RTA_DATA(rta), data, data_length);
|
||||
n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(length);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int get_ifindex(const char *name)
|
||||
{
|
||||
struct ifreq ifr;
|
||||
int sk, err;
|
||||
|
||||
if (!name)
|
||||
return -1;
|
||||
|
||||
sk = socket(PF_INET, SOCK_DGRAM, 0);
|
||||
if (sk < 0)
|
||||
return -1;
|
||||
|
||||
memset(&ifr, 0, sizeof ifr);
|
||||
strnkcpy(ifr.ifr_name, name, sizeof ifr.ifr_name);
|
||||
|
||||
err = ioctl(sk, SIOCGIFINDEX, &ifr);
|
||||
close(sk);
|
||||
if (err < 0)
|
||||
return -1;
|
||||
|
||||
return ifr.ifr_ifindex;
|
||||
}
|
||||
|
||||
// 32-bit position values are relatively prime to 37, so the residue mod37
|
||||
// gives a unique mapping for each value. Gives correct result for v=0.
|
||||
static int trailz(uint32_t v)
|
||||
{
|
||||
static const int bpm37[] = {
|
||||
32, 0, 1, 26, 2, 23, 27, 0, 3, 16, 24, 30, 28, 11, 0, 13, 4, 7, 17,
|
||||
0, 25, 22, 31, 15, 29, 10, 12, 6, 0, 21, 14, 9, 5, 20, 8, 19, 18
|
||||
};
|
||||
return bpm37[(-v & v) % 37];
|
||||
}
|
||||
|
||||
// sn must be in network order
|
||||
static inline int subnet4_to_prefixlen(uint32_t sn)
|
||||
{
|
||||
return 32 - trailz(sn);
|
||||
}
|
||||
|
||||
// str_bcast is optional.
|
||||
void perform_ip_subnet_bcast(struct ifchd_client *cl,
|
||||
const char *str_ipaddr,
|
||||
const char *str_subnet,
|
||||
const char *str_bcast)
|
||||
{
|
||||
uint8_t request[NLMSG_ALIGN(sizeof(struct nlmsghdr)) +
|
||||
NLMSG_ALIGN(sizeof(struct ifaddrmsg)) +
|
||||
RTA_LENGTH(sizeof(struct in6_addr))];
|
||||
struct in_addr ipaddr, subnet, bcast;
|
||||
struct sockaddr_nl nl_addr;
|
||||
struct nlmsghdr *header;
|
||||
struct ifaddrmsg *ifaddrmsg;
|
||||
int nls, ifidx, r;
|
||||
uint8_t prefixlen;
|
||||
|
||||
if (!str_ipaddr) {
|
||||
log_line("%s: (%s) interface ip address is NULL",
|
||||
cl->ifnam, __func__);
|
||||
return;
|
||||
}
|
||||
if (!str_subnet) {
|
||||
log_line("%s: (%s) interface subnet address is NULL",
|
||||
cl->ifnam, __func__);
|
||||
return;
|
||||
}
|
||||
|
||||
if (!is_permitted(cl->ifnam))
|
||||
return;
|
||||
ifidx = get_ifindex(cl->ifnam);
|
||||
if (ifidx < 0) {
|
||||
log_line("%s: (%s) can't get interface index",
|
||||
cl->ifnam, __func__);
|
||||
return;
|
||||
}
|
||||
|
||||
if (inet_pton(AF_INET, str_ipaddr, &ipaddr) <= 0) {
|
||||
log_line("%s: (%s) bad interface ip address: '%s'",
|
||||
cl->ifnam, __func__, str_ipaddr);
|
||||
return;
|
||||
}
|
||||
|
||||
if (inet_pton(AF_INET, str_subnet, &subnet) <= 0) {
|
||||
log_line("%s: (%s) bad interface subnet address: '%s'",
|
||||
cl->ifnam, __func__, str_subnet);
|
||||
return;
|
||||
}
|
||||
prefixlen = subnet4_to_prefixlen(subnet.s_addr);
|
||||
|
||||
if (str_bcast) {
|
||||
if (inet_pton(AF_INET, str_bcast, &bcast) <= 0) {
|
||||
log_line("%s: (%s) bad interface broadcast address: '%s'",
|
||||
cl->ifnam, __func__, str_bcast);
|
||||
return;
|
||||
}
|
||||
} else {
|
||||
// Generate the standard broadcast address if unspecified.
|
||||
bcast.s_addr = ipaddr.s_addr | htonl(0xfffffffflu >> prefixlen);
|
||||
}
|
||||
|
||||
memset(&request, 0, sizeof request);
|
||||
header = (struct nlmsghdr *)request;
|
||||
header->nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg));
|
||||
header->nlmsg_type = RTM_NEWADDR;
|
||||
header->nlmsg_flags = NLM_F_REPLACE | NLM_F_ACK | NLM_F_REQUEST;
|
||||
header->nlmsg_seq = 1;
|
||||
|
||||
ifaddrmsg = NLMSG_DATA(header);
|
||||
ifaddrmsg->ifa_family = AF_INET;
|
||||
ifaddrmsg->ifa_prefixlen = prefixlen;
|
||||
ifaddrmsg->ifa_flags = IFA_F_PERMANENT;
|
||||
ifaddrmsg->ifa_scope = RT_SCOPE_UNIVERSE;
|
||||
ifaddrmsg->ifa_index = ifidx;
|
||||
|
||||
if (add_rtattr(header, sizeof request, IFA_LOCAL,
|
||||
&ipaddr, sizeof ipaddr) < 0) {
|
||||
log_line("%s: (%s) couldn't add IFA_LOCAL to nlmsg",
|
||||
cl->ifnam, __func__);
|
||||
return;
|
||||
}
|
||||
if (add_rtattr(header, sizeof request, IFA_BROADCAST,
|
||||
&bcast, sizeof bcast) < 0) {
|
||||
log_line("%s: (%s) couldn't add IFA_BROADCAST to nlmsg",
|
||||
cl->ifnam, __func__);
|
||||
return;
|
||||
}
|
||||
|
||||
nls = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
|
||||
if (nls < 0) {
|
||||
log_line("%s: (%s) netlink socket open failed: %s",
|
||||
cl->ifnam, __func__, strerror(errno));
|
||||
return;
|
||||
}
|
||||
|
||||
memset(&nl_addr, 0, sizeof nl_addr);
|
||||
nl_addr.nl_family = AF_NETLINK;
|
||||
|
||||
retry_sendto:
|
||||
r = sendto(nls, request, header->nlmsg_len, 0,
|
||||
(struct sockaddr *)&nl_addr, sizeof nl_addr);
|
||||
if (r < 0) {
|
||||
if (errno == EINTR)
|
||||
goto retry_sendto;
|
||||
else {
|
||||
log_line("%s: (%s) netlink sendto socket failed: %s",
|
||||
cl->ifnam, __func__, strerror(errno));
|
||||
close(nls);
|
||||
return;
|
||||
}
|
||||
}
|
||||
close(nls);
|
||||
log_line("Interface IP set to: '%s'", str_ipaddr);
|
||||
log_line("Interface subnet set to: '%s'", str_subnet);
|
||||
if (str_bcast)
|
||||
log_line("Broadcast address set to: '%s'", str_bcast);
|
||||
|
||||
// XXX: Would be nice to do this via netlink, too.
|
||||
if (set_if_flag(cl, (IFF_UP | IFF_RUNNING)))
|
||||
return;
|
||||
}
|
||||
|
||||
|
||||
/* Sets IP address on an interface and brings it up. */
|
||||
void perform_ip(struct ifchd_client *cl, const char *str, size_t len)
|
||||
{
|
||||
|
|
|
|||
Loading…
Reference in New Issue
Block a user