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Further netlink implementation. Not working yet.

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Signed-off-by: Benjamin Cama <benoar@dolka.fr>
This commit is contained in:
Benjamin Cama 2011-08-15 22:59:13 +02:00
parent c7b02a0927
commit 7aa8cc3dc0
1 changed files with 220 additions and 101 deletions
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307
l2tpns.c
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@ -40,6 +40,7 @@ char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.176 2011/01/20 12:48:40 bodea Exp
#include <sys/sysinfo.h> #include <sys/sysinfo.h>
#include <libcli.h> #include <libcli.h>
#include <linux/netlink.h> #include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include "md5.h" #include "md5.h"
#include "l2tpns.h" #include "l2tpns.h"
@ -65,8 +66,6 @@ int clifd = -1; // Socket listening for CLI connections.
int daefd = -1; // Socket listening for DAE connections. int daefd = -1; // Socket listening for DAE connections.
int snoopfd = -1; // UDP file handle for sending out intercept data int snoopfd = -1; // UDP file handle for sending out intercept data
int *radfds = NULL; // RADIUS requests file handles int *radfds = NULL; // RADIUS requests file handles
int ifrfd = -1; // File descriptor for routing, etc
int ifr6fd = -1; // File descriptor for IPv6 routing, etc
int rand_fd = -1; // Random data source int rand_fd = -1; // Random data source
int cluster_sockfd = -1; // Intra-cluster communications socket. int cluster_sockfd = -1; // Intra-cluster communications socket.
int epollfd = -1; // event polling int epollfd = -1; // event polling
@ -525,86 +524,101 @@ static void initnetlink(void)
nlfd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); nlfd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
if (nlfd < 0) if (nlfd < 0)
return; // don't use netlink {
LOG(0, 0, 0, "Can't create netlink socket: %s\n", strerror(errno));
exit(1);
}
memset(&nladdr, 0, sizeof(nladdr)); memset(&nladdr, 0, sizeof(nladdr));
nladdr.nl_family = AF_NETLINK; nladdr.nl_family = AF_NETLINK;
nladdr.nl_pid = getpid(); nladdr.nl_pid = getpid();
if (bind(fd, (struct sockaddr *)&nladdr, sizeof(nladdr)) < 0) if (bind(nlfd, (struct sockaddr *)&nladdr, sizeof(nladdr)) < 0)
{ {
close(fd); LOG(0, 0, 0, "Can't bind netlink socket: %s\n", strerror(errno));
fd = -1; exit(1);
return; // don't use netlink
} }
} }
static ssize_t netlink_send(struct nlmsghdr *nh) static ssize_t netlink_send(struct nlmsghdr *nh, int want_ack)
{ {
struct sockaddr_nl nladdr; struct sockaddr_nl nladdr;
struct iovec iov; struct iovec iov;
struct msghdr msg; struct msghdr msg;
ssize_t len;
char buf[4096];
struct nlmsghdr *ack_nh;
nh->nlmsg_pid = getpid(); nh->nlmsg_pid = getpid();
nh->nlmsg_seq = ++nlseqnum; nh->nlmsg_seq = ++nlseqnum;
if (want_ack)
nh->nlmsg_flags |= NLM_F_ACK; nh->nlmsg_flags |= NLM_F_ACK;
iov = { (void *)nh, nh->msg_len };
// set kernel address // set kernel address
memset(nladdr, 0, sizeof(nladdr)); memset(&nladdr, 0, sizeof(nladdr));
nladdr.nl_family = AF_NETLINK; nladdr.nl_family = AF_NETLINK;
msg = { (void *)&nladdr, sizeof(nladdr), &iov, 1, NULL, 0, 0 };
if ((len = sendmsg(nlfd, &msg, 0)) < 0) iov = (struct iovec){ (void *)nh, nh->nlmsg_len };
return len; // return error code msg = (struct msghdr){ (void *)&nladdr, sizeof(nladdr), &iov, 1, NULL, 0, 0 };
return sendmsg(nlfd, &msg, 0);
}
static ssize_t netlink_recv(char *buf, ssize_t len)
{
struct sockaddr_nl nladdr;
struct iovec iov;
struct msghdr msg;
// set kernel address
memset(&nladdr, 0, sizeof(nladdr));
nladdr.nl_family = AF_NETLINK;
iov = (struct iovec){ buf, len };
msg = (struct msghdr){ (void *)&nladdr, sizeof(nladdr), &iov, 1, NULL, 0, 0 };
return recvmsg(nlfd, &msg, 0);
}
static ssize_t netlink_check_ack(struct nlmsghdr *ack_nh, int msg_count)
{
ssize_t len;
uint32_t seqnum;
// expect ack // expect ack
iov = { buf, sizeof(buf) }; for (; NLMSG_OK (ack_nh, len); ack_nh = NLMSG_NEXT (ack_nh, len))
msg = { (void *)&nladdr, sizeof(nladdr), &iov, 1, NULL, 0, 0 };
if ((len = recvmsg(nlfd, &msg, 0)) < 0)
return len; // return error code
for (ack_nh = (struct nlmsghdr *)buf; NLMSG_OK (ack_nh, len);
ack_nh = NLMSG_NEXT (ack_nh, len))
{ {
if (ack_nh->nlmsg_type == NLMSG_DONE) if (ack_nh->nlmsg_type == NLMSG_DONE)
return 1; // didn't get the ack return msg_count != 0 || seqnum != nlseqnum;
// 1 => lost an ack
if (ack_nh->nlmsg_type == NLMSG_ERROR) if (ack_nh->nlmsg_type == NLMSG_ERROR)
{ {
struct nlmsgerr *errmsg = NLMSG_DATA(ack_nh); struct nlmsgerr *errmsg = NLMSG_DATA(ack_nh);
if (errmsg->error) if (errmsg->error)
return errmsg->error; // got an error back return errmsg->error; // got an error back
if (errmsg->msg.nlmsg_seq == nh->nlmsg_seq)
return 0; // ack received
else else
return 2; // wrong seq number?! {
// ack received
--msg_count;
if (errmsg->msg.nlmsg_seq > seqnum);
seqnum = errmsg->msg.nlmsg_seq;
} }
}
else
// unknown message // unknown message
LOG(3, 0, 0, "Got an unknown netlink message: type %d\n", ack_nh->nlmsg_type); LOG(3, 0, 0, "Got an unknown netlink message: type %d\n", ack_nh->nlmsg_type);
} }
return 3; // no end message?! return 1; // malformed message?!
} }
// defined in linux/ipv6.h, but tricky to include from user-space
// TODO: move routing to use netlink rather than ioctl
struct in6_ifreq {
struct in6_addr ifr6_addr;
__u32 ifr6_prefixlen;
unsigned int ifr6_ifindex;
};
// //
// Set up TUN interface // Set up TUN interface
static void inittun(void) static void inittun(void)
{ {
struct ifinfomsg ifinfo;
struct ifreq ifr; struct ifreq ifr;
struct in6_ifreq ifr6; char buf[4096];
struct sockaddr_in sin = {0}; struct nlmsghdr resp_nh;
memset(&ifr, 0, sizeof(ifr)); memset(&ifr, 0, sizeof(ifr));
ifr.ifr_flags = IFF_TUN; ifr.ifr_flags = IFF_TUN;
@ -625,79 +639,184 @@ static void inittun(void)
} }
assert(strlen(ifr.ifr_name) < sizeof(config->tundevice)); assert(strlen(ifr.ifr_name) < sizeof(config->tundevice));
strncpy(config->tundevice, ifr.ifr_name, sizeof(config->tundevice) - 1); strncpy(config->tundevice, ifr.ifr_name, sizeof(config->tundevice) - 1);
{
struct nlmsghdr nlh;
{ {
LOG(0, 0, 0, "Error setting up tun device: %s", strerror(errno)); // get the interface index
exit(1); ssize_t len;
} struct {
} struct nlmsghdr nh;
ifrfd = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP); struct ifinfomsg ifinfo __attribute__ ((aligned(NLMSG_ALIGNTO)));
struct rtattr ifname_rta __attribute__ ((aligned(RTA_ALIGNTO)));
char ifname[IFNAMSIZ];
} req;
sin.sin_family = AF_INET; req.nh.nlmsg_type = RTM_GETLINK;
sin.sin_addr.s_addr = config->bind_address ? config->bind_address : 0x01010101; // 1.1.1.1 req.nh.nlmsg_flags = NLM_F_REQUEST;
memcpy(&ifr.ifr_addr, &sin, sizeof(struct sockaddr));
if (ioctl(ifrfd, SIOCSIFADDR, (void *) &ifr) < 0) req.ifinfo.ifi_family = AF_UNSPEC; // as the man says
{
LOG(0, 0, 0, "Error setting tun address: %s\n", strerror(errno)); req.ifname_rta.rta_len = RTA_LENGTH(strlen(config->tundevice)+1);
exit(1); req.ifname_rta.rta_type = IFLA_IFNAME;
} strncpy(req.ifname, config->tundevice, IFNAMSIZ-1);
/* Bump up the qlen to deal with bursts from the network */
ifr.ifr_qlen = 1000; if(netlink_send(&req.nh, 0) < 0 || (len = netlink_recv(buf, sizeof(buf))) < 0)
if (ioctl(ifrfd, SIOCSIFTXQLEN, (void *) &ifr) < 0)
{
LOG(0, 0, 0, "Error setting tun queue length: %s\n", strerror(errno));
exit(1);
}
/* set MTU to modem MRU */
ifr.ifr_mtu = MRU;
if (ioctl(ifrfd, SIOCSIFMTU, (void *) &ifr) < 0)
{
LOG(0, 0, 0, "Error setting tun MTU: %s\n", strerror(errno));
exit(1);
}
ifr.ifr_flags = IFF_UP;
if (ioctl(ifrfd, SIOCSIFFLAGS, (void *) &ifr) < 0)
{
LOG(0, 0, 0, "Error setting tun flags: %s\n", strerror(errno));
exit(1);
}
if (ioctl(ifrfd, SIOCGIFINDEX, (void *) &ifr) < 0)
{ {
LOG(0, 0, 0, "Error getting tun ifindex: %s\n", strerror(errno)); LOG(0, 0, 0, "Error getting tun ifindex: %s\n", strerror(errno));
exit(1); exit(1);
} }
tunidx = ifr.ifr_ifindex;
resp_nh = (struct nlmsghdr *)buf;
if (NLMSG_OK (resp_nh, len) && resp_nh.nlmsg_type == RTM_GETLINK)
{
memcpy(&ifinfo, NLMSG_DATA(resp_nh), sizeof(ifinfo));
// got index
tunidx = ifinfo.ifi_index;
}
else
{
LOG(0, 0, 0, "Malformed answer getting tun ifindex\n");
exit(1);
}
}
{
ssize_t err;
struct {
// interface setting
struct nlmsghdr nh;
struct ifinfomsg ifinfo __attribute__ ((aligned(NLMSG_ALIGNTO)));
struct rtattr txqlen_rta __attribute__ ((aligned(RTA_ALIGNTO)));
uint32_t txqlen;
struct rtattr mtu_rta __attribute__ ((aligned(RTA_ALIGNTO)));
uint32_t mtu;
// IPv4 address
struct nlmsghdr addr_nh __attribute __ ((aligned(NLMSG_ALIGNTO)));
struct ifaddrmsg ifaddr __attribute __ ((aligned(NLMSG_ALIGNTO)));
struct rtattr addr_rta __attribute __ ((aligned(RTA_ALIGNTO)));
struct in_addr addr;
// IPv6 LL address
struct nlmsghdr lladdr6_nh __attribute __ ((aligned(NLMSG_ALIGNTO)));
struct ifaddrmsg llifaddr6 __attribute __ ((aligned(NLMSG_ALIGNTO)));
struct rtattr lladdr6_rta __attribute __ ((aligned(RTA_ALIGNTO)));
struct in6_addr lladdr6;
// IPv6 global address
struct nlmsghdr addr6_nh __attribute __ ((aligned(NLMSG_ALIGNTO)));
struct ifaddrmsg ifaddr6 __attribute __ ((aligned(NLMSG_ALIGNTO)));
struct rtattr addr6_rta __attribute __ ((aligned(RTA_ALIGNTO)));
struct in6_addr addr6;
// end header
struct nlmsghdr end_nh __attribute __ ((aligned(NLMSG_ALIGNTO)));
} req;
char buf[4096];
memset(&req, 0, sizeof(req));
req.nh.nlmsg_type = RTM_NEWLINK;
req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_REPLACE | NLM_F_MULTI;
req.ifinfo = ifinfo;
req.ifinfo.ifi_flags |= IFF_UP; // set interface up
req.ifinfo.ifi_change = IFF_UP; // only change this flag
req.txqlen_rta.rta_len = RTA_LENGTH(sizeof(req.txqlen));
req.txqlen_rta.rta_type = IFLA_TXQLEN;
/* Bump up the qlen to deal with bursts from the network */
req.txqlen = 1000;
req.mtu_rta.rta_len = RTA_LENGTH(sizeof(req.txqlen));
req.mtu_rta.rta_type = IFLA_MTU;
/* set MTU to modem MRU */
req.mtu = MRU;
req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifinfo)
+ req.txqlen_rla.rta_len
+ req.mtu_rta.rta_len);
req.addr_nh.nlmsg_type = RTM_NEWADDR;
req.addr_nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_MULTI;
req.ifaddr.ifa_family = AF_INET;
req.ifaddr.ifa_prefixlen = 32;
req.ifaddr.ifa_index = ifinfo.ifi_index;
req.addr_rta.rta_len = RTA_LENGTH(sizeof(req.addr));
req.addr_rta.rta_type = IFA_ADDRESS;
req.addr.s_addr = config->bind_address ?
config->bind_address : 0x01010101; // 1.1.1.1
req.addr_nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifaddr)
+ req.addr_rta.rta_len);
// Only setup IPv6 on the tun device if we have a configured prefix // Only setup IPv6 on the tun device if we have a configured prefix
if (config->ipv6_prefix.s6_addr[0]) { if (config->ipv6_prefix.s6_addr[0]) {
ifr6fd = socket(PF_INET6, SOCK_DGRAM, 0); req.lladdr6_nh.nlmsg_type = RTM_NEWADDR;
req.lladdr6_nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_MULTI;
req.llifaddr6.ifa_family = AF_INET6;
req.llifaddr6.ifa_prefixlen = 64;
req.llifaddr6.ifa_scope = RT_SCOPE_LINK;
req.llifaddr6.ifa_index = ifinfo.ifi_index;
req.lladdr6_rta.rta_len = RTA_LENGTH(sizeof(req.lladdr6));
req.lladdr6_rta.rta_type = IFA_LOCAL;
// Link local address is FE80::1 // Link local address is FE80::1
memset(&ifr6.ifr6_addr, 0, sizeof(ifr6.ifr6_addr)); memset(&req.lladdr6, 0, sizeof(req.lladdr6));
ifr6.ifr6_addr.s6_addr[0] = 0xFE; req.lladdr6.s6_addr[0] = 0xFE;
ifr6.ifr6_addr.s6_addr[1] = 0x80; req.lladdr6.s6_addr[1] = 0x80;
ifr6.ifr6_addr.s6_addr[15] = 1; req.lladdr6.s6_addr[15] = 1;
ifr6.ifr6_prefixlen = 64;
ifr6.ifr6_ifindex = ifr.ifr_ifindex; req.lladdr6_nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifaddr)
if (ioctl(ifr6fd, SIOCSIFADDR, (void *) &ifr6) < 0) + req.lladdr6_rta.rta_len);
req.addr6_nh.nlmsg_type = RTM_NEWADDR;
req.addr6_nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_MULTI;
req.ifaddr6.ifa_family = AF_INET6;
req.ifaddr6.ifa_prefixlen = 64;
req.ifaddr6.ifa_scope = RT_SCOPE_UNIVERSE;
req.ifaddr6.ifa_index = ifinfo.ifi_index;
req.addr6_rta.rta_len = RTA_LENGTH(sizeof(req.addr6));
req.addr6_rta.rta_type = IFA_LOCAL;
// Global address is prefix::1
req.addr6 = config->ipv6_prefix;
req.addr6.s6_addr[15] = 1;
req.lladdr6_nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifaddr)
+ req.lladdr6_rta.rta_len);
req.end_nh.nlmsg_type = NLMSG_DONE;
req.end_nh.nlmsg_len = NLMSG_LENGTH(0);
}
else
{ {
LOG(0, 0, 0, "Error setting tun IPv6 link local address:" // we terminate at the beginning of IPv6 stuff
" %s\n", strerror(errno)); req.lladdr6_nh.nlmsg_type = NLMSG_DONE;
req.lladdr6_nh.nlmsg_len = NLMSG_LENGTH(0);
} }
// Global address is prefix::1 if (netlink_send(&req.nh, 1) < 0)
memset(&ifr6.ifr6_addr, 0, sizeof(ifr6.ifr6_addr)); LOG(0, 0, 0, "Error setting up tun device: %s\n", strerror(errno));
ifr6.ifr6_addr = config->ipv6_prefix; exit(1);
ifr6.ifr6_addr.s6_addr[15] = 1; }
ifr6.ifr6_prefixlen = 64;
ifr6.ifr6_ifindex = ifr.ifr_ifindex; if (netlink_recv(buf, sizeof(buf)) < 0)
if (ioctl(ifr6fd, SIOCSIFADDR, (void *) &ifr6) < 0)
{ {
LOG(0, 0, 0, "Error setting tun IPv6 global address: %s\n", LOG(0, 0, 0, "Error waiting ack for setting up tun device: %s\n", strerror(errno));
strerror(errno)); exit(1);
}
resp_nh = (struct nlmsghdr *)buf;
if ((err = netlink_check_ack(resp_nh, 4)))
{
if (err < 0)
LOG(0, 0, 0, "Error while receiving tun device ack: %s\n", strerror(errno));
else
LOG(0, 0, 0, "Error while receiving tun device ack\n", strerror(errno));
exit(1);
} }
} }
} }