emo/ndhc
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Wire up the netlink socket to the epoll handler. Still need to actually

Browse Source 
react to events in the processing function.
Pass the client_state structure to the netlink code explicitly rather than
making it a global variable.
This commit is contained in:
Nicholas J. Kain 2011-03-29 15:34:00 -04:00
parent 55bc002ad6
commit 9d03795a15
5 changed files with 100 additions and 46 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
ndhc/config.h
View File

@ -24,13 +24,22 @@ enum {
LM_RAW LM_RAW
}; };
enum {
IFS_NONE = 0,
IFS_UP,
IFS_DOWN,
IFS_SHUT,
IFS_REMOVED
};
struct client_state_t { struct client_state_t {
unsigned long long leaseStartTime; unsigned long long leaseStartTime;
int dhcpState; int dhcpState;
int arpPrevState; int arpPrevState;
int ifsPrevState;
int listenMode; int listenMode;
int packetNum; int packetNum;
int epollFd, signalFd, listenFd, arpFd; int epollFd, signalFd, listenFd, arpFd, nlFd;
int timeout; int timeout;
uint32_t requestedIP, serverAddr; uint32_t requestedIP, serverAddr;
uint32_t lease, t1, t2, xid; uint32_t lease, t1, t2, xid;

12
ndhc/ndhc.c
View File

@ -33,7 +33,6 @@
#include <signal.h> #include <signal.h>
#include <time.h> #include <time.h>
#include <string.h> #include <string.h>
#include <sys/ioctl.h>
#include <sys/epoll.h> #include <sys/epoll.h>
#include <sys/signalfd.h> #include <sys/signalfd.h>
#include <net/if.h> #include <net/if.h>
@ -67,6 +66,7 @@
struct client_state_t cs = { struct client_state_t cs = {
.dhcpState = DS_INIT_SELECTING, .dhcpState = DS_INIT_SELECTING,
.arpPrevState = DS_NULL, .arpPrevState = DS_NULL,
.ifsPrevState = IFS_NONE,
.listenMode = LM_NONE, .listenMode = LM_NONE,
.packetNum = 0, .packetNum = 0,
.xid = 0, .xid = 0,
@ -81,6 +81,7 @@ struct client_state_t cs = {
.signalFd = -1, .signalFd = -1,
.listenFd = -1, .listenFd = -1,
.arpFd = -1, .arpFd = -1,
.nlFd = -1,
}; };
struct client_config_t client_config = { struct client_config_t client_config = {
@ -223,6 +224,7 @@ static void do_work(void)
if (cs.epollFd == -1) if (cs.epollFd == -1)
suicide("epoll_create1 failed"); suicide("epoll_create1 failed");
setup_signals(&cs); setup_signals(&cs);
epoll_add(&cs, cs.nlFd);
change_listen_mode(&cs, LM_RAW); change_listen_mode(&cs, LM_RAW);
handle_timeout(&cs); handle_timeout(&cs);
@ -243,6 +245,8 @@ static void do_work(void)
handle_packet(&cs); handle_packet(&cs);
else if (fd == cs.arpFd) else if (fd == cs.arpFd)
handle_arp_response(&cs); handle_arp_response(&cs);
else if (fd == cs.nlFd)
handle_nl_message(&cs);
else else
suicide("epoll_wait: unknown fd"); suicide("epoll_wait: unknown fd");
} }
@ -363,11 +367,11 @@ int main(int argc, char **argv)
write_pid(pidfile); write_pid(pidfile);
} }
if (nl_open() < 0) { if (nl_open(&cs) < 0) {
log_line("FATAL - failed to open netlink socket"); log_line("FATAL - failed to open netlink socket");
exit(EXIT_FAILURE); exit(EXIT_FAILURE);
} }
if (nl_getifdata(client_config.interface) < 0) { if (nl_getifdata(client_config.interface, &cs) < 0) {
log_line("FATAL - failed to get interface MAC and index"); log_line("FATAL - failed to get interface MAC and index");
exit(EXIT_FAILURE); exit(EXIT_FAILURE);
} }
@ -398,6 +402,6 @@ int main(int argc, char **argv)
do_work(); do_work();
nl_close(); nl_close(&cs);
return EXIT_SUCCESS; return EXIT_SUCCESS;
} }

111
ndhc/netlink.c
View File

@ -17,23 +17,17 @@
#include <unistd.h> #include <unistd.h>
#include <net/if.h> #include <net/if.h>
#include <stdio.h> #include <stdio.h>
#include <stdlib.h>
#include <strings.h> #include <strings.h>
#include <string.h> #include <string.h>
#include <sys/select.h> #include <sys/select.h>
#include <fcntl.h> #include <fcntl.h>
#include "netlink.h" #include "netlink.h"
#include "config.h"
#include "log.h" #include "log.h"
// OS_REMOVED -> exit
// OS_SHUT -> exit
// OS_DOWN -> action
// OS_UP -> action
#define NLMSG_RECVSIZE 8192 #define NLMSG_RECVSIZE 8192
static int nl_socket = -1;
static unsigned int nl_seq; static unsigned int nl_seq;
/* internal callback handling */ /* internal callback handling */
@ -43,7 +37,8 @@ static __u32 nlcb_pid;
static unsigned int nlcb_seq; static unsigned int nlcb_seq;
static char nlcb_run; static char nlcb_run;
int nl_open() { int nl_open(struct client_state_t *cs)
{
struct sockaddr_nl nlsock = { struct sockaddr_nl nlsock = {
.nl_family = AF_NETLINK, .nl_family = AF_NETLINK,
.nl_pad = 0, .nl_pad = 0,
@ -53,37 +48,40 @@ int nl_open() {
nlcb_pid = nlsock.nl_pid; nlcb_pid = nlsock.nl_pid;
assert(nl_socket == -1); assert(cs->nlFd == -1);
nl_socket = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE); cs->nlFd = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
if (nl_socket == -1) return -1; if (cs->nlFd == -1)
return -1;
if (bind(nl_socket, (const struct sockaddr *)&nlsock, sizeof(nlsock))) if (bind(cs->nlFd, (const struct sockaddr *)&nlsock, sizeof(nlsock)))
goto err_close; goto err_close;
if (fcntl(nl_socket, F_SETFD, FD_CLOEXEC)) if (fcntl(cs->nlFd, F_SETFD, FD_CLOEXEC))
goto err_close; goto err_close;
return 0; return 0;
err_close: err_close:
nl_close(); nl_close(cs);
return -1; return -1;
} }
void nl_close() { void nl_close(struct client_state_t *cs)
close(nl_socket); {
nl_socket = -1; close(cs->nlFd);
cs->nlFd = -1;
} }
void nl_queryifstatus(int ifidx) { void nl_queryifstatus(int ifidx, struct client_state_t *cs)
{
struct { struct {
struct nlmsghdr hdr; struct nlmsghdr hdr;
struct ifinfomsg ifinfo; struct ifinfomsg ifinfo;
} req; } req;
req.hdr.nlmsg_len = sizeof(req); req.hdr.nlmsg_len = sizeof req;
req.hdr.nlmsg_type = RTM_GETLINK; req.hdr.nlmsg_type = RTM_GETLINK;
req.hdr.nlmsg_flags = NLM_F_REQUEST | NLM_F_ROOT; req.hdr.nlmsg_flags = NLM_F_REQUEST | NLM_F_ROOT;
req.hdr.nlmsg_seq = ++nl_seq; req.hdr.nlmsg_seq = ++nl_seq;
@ -93,11 +91,13 @@ void nl_queryifstatus(int ifidx) {
req.ifinfo.ifi_flags = IFF_UP; req.ifinfo.ifi_flags = IFF_UP;
req.ifinfo.ifi_change = 0xffffffff; req.ifinfo.ifi_change = 0xffffffff;
send(nl_socket, &req, sizeof(req),0); send(cs->nlFd, &req, sizeof req, 0);
} }
// Decode netlink messages and process them
static void nl_handlemsg(struct nlmsghdr *msg, unsigned int len) { static void nl_handlemsg(struct nlmsghdr *msg, unsigned int len,
struct client_state_t *cs)
{
if (len < sizeof(*msg)) return; if (len < sizeof(*msg)) return;
while(NLMSG_OK(msg,len)) { while(NLMSG_OK(msg,len)) {
@ -118,17 +118,41 @@ static void nl_handlemsg(struct nlmsghdr *msg, unsigned int len) {
if (ifinfo->ifi_index != client_config.ifindex) if (ifinfo->ifi_index != client_config.ifindex)
break; break;
if (ifinfo->ifi_flags & IFF_UP) { if (ifinfo->ifi_flags & IFF_UP) {
if (ifinfo->ifi_flags & IFF_RUNNING) if (ifinfo->ifi_flags & IFF_RUNNING) {
printf("XXX_OS_UP() NYI\n"); if (cs->ifsPrevState != IFS_UP) {
else cs->ifsPrevState = IFS_UP;
printf("XXX_OS_DOWN() NYI\n"); /*
} else * If we have a lease, then check to see
printf("XXX_OS_SHUT() NYI\n"); * if our gateway is still valid. If it fails,
* state -> INIT_REBOOT.
*
* If we don't have a lease, state -> INIT.
*/
}
} else {
if (cs->ifsPrevState != IFS_DOWN) {
cs->ifsPrevState = IFS_DOWN;
/*
* state -> DOWN
*/
}
}
} else {
if (cs->ifsPrevState != IFS_SHUT) {
cs->ifsPrevState = IFS_SHUT;
log_line("Interface shut down; exiting.");
exit(EXIT_SUCCESS);
}
}
break; break;
case RTM_DELLINK: case RTM_DELLINK:
if (ifinfo->ifi_index != client_config.ifindex) if (ifinfo->ifi_index != client_config.ifindex)
break; break;
printf("XXX_OS_REMOVED() NYI\n"); if (cs->ifsPrevState != IFS_REMOVED) {
cs->ifsPrevState = IFS_REMOVED;
log_line("Interface removed; exiting.");
exit(EXIT_SUCCESS);
}
break; break;
default: default:
break; break;
@ -138,21 +162,35 @@ static void nl_handlemsg(struct nlmsghdr *msg, unsigned int len) {
} }
} }
static void nl_sync_dump() { void handle_nl_message(struct client_state_t *cs)
{
char c[NLMSG_RECVSIZE];
struct nlmsghdr *msg = (struct nlmsghdr *)c;
int n;
assert(cs->nlFd != -1);
n = recv(cs->nlFd, c, NLMSG_RECVSIZE, 0);
nl_handlemsg(msg, n, cs);
}
// Wait for and synchronously process netlink replies until a callback completes
static void nl_sync_dump(struct client_state_t *cs)
{
char c[NLMSG_RECVSIZE]; char c[NLMSG_RECVSIZE];
struct nlmsghdr *msg = (struct nlmsghdr *)c; struct nlmsghdr *msg = (struct nlmsghdr *)c;
int n; int n;
nlcb_seq = nl_seq; nlcb_seq = nl_seq;
for(nlcb_run = 1; nlcb_run;) { for(nlcb_run = 1; nlcb_run;) {
n = recv(nl_socket, c, NLMSG_RECVSIZE, 0); n = recv(cs->nlFd, c, NLMSG_RECVSIZE, 0);
assert(n >= 0); assert(n >= 0);
nl_handlemsg(msg,n); nl_handlemsg(msg, n, cs);
} }
} }
// Callback function for getting interface mac address and index. // Callback function for getting interface mac address and index.
static void copy_ifdata(struct nlmsghdr *msg, void **args) { static void copy_ifdata(struct nlmsghdr *msg, void **args)
{
struct ifinfomsg *ifinfo = NLMSG_DATA(msg); struct ifinfomsg *ifinfo = NLMSG_DATA(msg);
struct rtattr *rta = IFLA_RTA(ifinfo); struct rtattr *rta = IFLA_RTA(ifinfo);
int len = NLMSG_PAYLOAD(msg, sizeof(*ifinfo)); int len = NLMSG_PAYLOAD(msg, sizeof(*ifinfo));
@ -193,7 +231,8 @@ static void copy_ifdata(struct nlmsghdr *msg, void **args) {
} }
// Gets interface mac address and index (synchronous). // Gets interface mac address and index (synchronous).
int nl_getifdata(const char *ifname) { int nl_getifdata(const char *ifname, struct client_state_t *cs)
{
struct { struct {
struct nlmsghdr hdr; struct nlmsghdr hdr;
struct ifinfomsg ifinfo; struct ifinfomsg ifinfo;
@ -206,12 +245,12 @@ int nl_getifdata(const char *ifname) {
req.hdr.nlmsg_pid = nlcb_pid; req.hdr.nlmsg_pid = nlcb_pid;
req.ifinfo.ifi_family = AF_UNSPEC; req.ifinfo.ifi_family = AF_UNSPEC;
if (send(nl_socket, &req, sizeof(req), 0) != sizeof(req)) return -1; if (send(cs->nlFd, &req, sizeof(req), 0) != sizeof(req)) return -1;
nlcb_function = copy_ifdata; nlcb_function = copy_ifdata;
nlcb_args[0] = NULL; nlcb_args[0] = NULL;
nl_sync_dump(); nl_sync_dump(cs);
return nlcb_args[0]?0:-1; return nlcb_args[0]?0:-1;
} }

11
ndhc/netlink.h
View File

@ -1,9 +1,12 @@
#ifndef NK_NETLINK_H_ #ifndef NK_NETLINK_H_
#define NK_NETLINK_H_ #define NK_NETLINK_H_
int nl_open(); #include "config.h"
void nl_close();
void nl_queryifstatus(int ifidx); int nl_open(struct client_state_t *cs);
int nl_getifdata(const char *ifname); void nl_close(struct client_state_t *cs);
void nl_queryifstatus(int ifidx, struct client_state_t *cs);
void handle_nl_message(struct client_state_t *cs);
int nl_getifdata(const char *ifname, struct client_state_t *cs);
#endif /* NK_NETLINK_H_ */ #endif /* NK_NETLINK_H_ */

1
ndhc/socket.c
View File

@ -23,7 +23,6 @@
#include <sys/types.h> #include <sys/types.h>
#include <sys/socket.h> #include <sys/socket.h>
#include <sys/ioctl.h>
#include <netinet/in.h> #include <netinet/in.h>
#include <unistd.h> #include <unistd.h>
#include <fcntl.h> #include <fcntl.h>