new

src/libip/Linux.c

@@ -0,0 +1,254 @@
+#include <u.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <asm/types.h>
+#include <net/if_arp.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+#include <net/if.h>
+#include <libc.h>
+#include <ip.h>
+
+/*
+ * Use netlink sockets to find interfaces.
+ * Thanks to Erik Quanstrom.
+ */
+static int
+netlinkrequest(int fd, int type, int (*fn)(struct nlmsghdr *h, Ipifc**, int), 
+	Ipifc **ifc, int index)
+{
+	char buf[1024];
+	int n;
+	struct sockaddr_nl nl;
+	struct {
+		struct nlmsghdr nlh;
+		struct rtgenmsg g;
+	} req;
+	struct nlmsghdr *h;
+
+	memset(&nl, 0, sizeof nl);
+	nl.nl_family = AF_NETLINK;
+
+	memset(&req, 0, sizeof req);
+	req.nlh.nlmsg_len = sizeof req;
+	req.nlh.nlmsg_type = type;
+	req.nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
+	req.nlh.nlmsg_pid = 0;
+	req.nlh.nlmsg_seq = 1;
+	req.g.rtgen_family = AF_NETLINK;
+
+	if(sendto(fd, (void*)&req, sizeof req, 0, (struct sockaddr*)&nl, sizeof nl) < 0)
+		return -1;
+
+	while((n=read(fd, buf, sizeof buf)) > 0){
+		for(h=(struct nlmsghdr*)buf; NLMSG_OK(h, n); h = NLMSG_NEXT(h, n)){
+			if(h->nlmsg_type == NLMSG_DONE)
+				return 0;
+			if(h->nlmsg_type == NLMSG_ERROR){
+				werrstr("netlink error");
+				return -1;
+			}
+			if(fn(h, ifc, index) < 0)
+				return -1;
+		}
+	}
+	werrstr("netlink error");
+	return -1;
+}
+
+static int
+devsocket(void)
+{
+	/* we couldn't care less which one; just want to talk to the kernel! */
+	static int dumb[3] = { AF_INET, AF_PACKET, AF_INET6 };
+	int i, fd;
+	
+	for(i=0; i<nelem(dumb); i++)
+		if((fd = socket(dumb[i], SOCK_DGRAM, 0)) >= 0)
+			return fd;
+	return -1;
+}
+
+static int
+parsertattr(struct rtattr **dst, int ndst, struct nlmsghdr *h, int type, int skip)
+{
+	struct rtattr *src;
+	int len;
+	
+	len = h->nlmsg_len - NLMSG_LENGTH(skip);
+	if(len < 0 || h->nlmsg_type != type){
+		werrstr("attrs too short");
+		return -1;
+	}
+	src = (struct rtattr*)((char*)NLMSG_DATA(h) + NLMSG_ALIGN(skip));
+
+	memset(dst, 0, ndst*sizeof dst[0]);
+	for(; RTA_OK(src, len); src = RTA_NEXT(src, len))
+		if(src->rta_type < ndst)
+			dst[src->rta_type] = src;
+	return 0;
+}
+
+static void
+rta2ip(int af, uchar *ip, struct rtattr *rta)
+{
+	memset(ip, 0, IPaddrlen);
+	
+	switch(af){
+	case AF_INET:
+		memmove(ip, v4prefix, IPv4off);
+		memmove(ip+IPv4off, RTA_DATA(rta), IPv4addrlen);
+		break;
+	case AF_INET6:
+		memmove(ip, RTA_DATA(rta), IPaddrlen);
+		break;
+	}
+}
+
+static int
+getlink(struct nlmsghdr *h, Ipifc **ipifclist, int index)
+{
+	char *p;
+	int fd;
+	struct rtattr *attr[IFLA_MAX+1];
+	struct ifinfomsg *ifi;
+	Ipifc *ifc;
+	
+	ifi = (struct ifinfomsg*)NLMSG_DATA(h);
+	if(index >= 0 && ifi->ifi_index != index)
+		return 0;
+
+	ifc = mallocz(sizeof *ifc, 1);
+	if(ifc == nil)
+		return -1;
+	ifc->index = ifi->ifi_index;
+
+	while(*ipifclist)
+		ipifclist = &(*ipifclist)->next;
+	*ipifclist = ifc;
+
+	if(parsertattr(attr, nelem(attr), h, RTM_NEWLINK, sizeof(struct ifinfomsg)) < 0)
+		return -1;
+
+	if(attr[IFLA_IFNAME])
+		p = (char*)RTA_DATA(attr[IFLA_IFNAME]);
+	else
+		p = "nil";
+	strecpy(ifc->dev, ifc->dev+sizeof ifc->dev, p);
+
+	if(attr[IFLA_MTU])
+		ifc->mtu = *(int*)RTA_DATA(attr[IFLA_MTU]);
+	
+	if(attr[IFLA_STATS]){
+		struct rtnl_link_stats *s;
+
+		s = RTA_DATA(attr[IFLA_STATS]);
+		ifc->pktin = s->rx_packets;
+		ifc->pktout = s->tx_packets;
+		ifc->errin = s->rx_errors;
+		ifc->errout = s->tx_errors;
+	}
+	
+	if((fd = devsocket()) > 0){
+		struct ifreq ifr;
+
+		memset(&ifr, 0, sizeof ifr);
+		strncpy(ifr.ifr_name, p, IFNAMSIZ);
+		ifr.ifr_mtu = 0;
+		if(ioctl(fd, SIOCGIFMTU, &ifr) >= 0)
+			ifc->rp.linkmtu = ifr.ifr_mtu;
+
+		memset(&ifr, 0, sizeof ifr);
+		strncpy(ifr.ifr_name, p, IFNAMSIZ);
+		if(ioctl(fd, SIOCGIFHWADDR, &ifr) >= 0
+		&& ifr.ifr_hwaddr.sa_family == ARPHRD_ETHER)
+			memmove(ifc->ether, ifr.ifr_hwaddr.sa_data, 6);
+		
+		close(fd);
+	}
+	return 0;
+}
+
+static int
+getaddr(struct nlmsghdr *h, Ipifc **ipifclist, int index)
+{
+	int mask;
+	Ipifc *ifc;
+	Iplifc *lifc, **l;
+	struct ifaddrmsg *ifa;
+	struct rtattr *attr[IFA_MAX+1];
+	
+	USED(index);
+
+	ifa = (struct ifaddrmsg*)NLMSG_DATA(h);
+	for(ifc=*ipifclist; ifc; ifc=ifc->next)
+		if(ifc->index == ifa->ifa_index)
+			break;
+	if(ifc == nil)
+		return 0;
+	if(parsertattr(attr, nelem(attr), h, RTM_NEWADDR, sizeof(struct ifaddrmsg)) < 0)
+		return -1;
+	
+	lifc = mallocz(sizeof *lifc, 1);
+	if(lifc == nil)
+		return -1;
+	for(l=&ifc->lifc; *l; l=&(*l)->next)
+		;
+	*l = lifc;
+
+	if(attr[IFA_ADDRESS] == nil)
+		attr[IFA_ADDRESS] = attr[IFA_LOCAL];
+	if(attr[IFA_ADDRESS] == nil)
+		return 0;
+
+	rta2ip(ifa->ifa_family, lifc->ip, attr[IFA_ADDRESS]);
+	
+	mask = ifa->ifa_prefixlen/8;
+	if(ifa->ifa_family == AF_INET)
+		mask += IPv4off;
+	memset(lifc->mask, 0xFF, mask);
+	memmove(lifc->net, lifc->ip, mask);
+	
+	if(attr[IFA_CACHEINFO]){
+		struct ifa_cacheinfo *ci;
+
+		ci = RTA_DATA(attr[IFA_CACHEINFO]);
+		lifc->preflt = ci->ifa_prefered;
+		lifc->validlt = ci->ifa_valid;
+	}
+	return 0;
+}
+
+Ipifc*
+readipifc(char *net, Ipifc *ifc, int index)
+{
+	int fd;
+
+	USED(net);
+	freeipifc(ifc);
+	ifc = nil;
+	
+	fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+	if(fd < 0)
+		return nil;
+	ifc = nil;
+	if(netlinkrequest(fd, RTM_GETLINK, getlink, &ifc, index) < 0
+	|| netlinkrequest(fd, RTM_GETADDR, getaddr, &ifc, index) < 0){
+		close(fd);
+		freeipifc(ifc);
+		return nil;
+	}
+	close(fd);
+	return ifc;
+}
+
+int
+_myetheraddr(uchar *to, char *dev)
+{
+	int fd;
+	struct ifreq ifr;
+	
+	return 0;
+}