[mirror_lxc.git] / src / include / netns_ifaddrs.c

#include <arpa/inet.h>
#include <errno.h>
#include <linux/if.h>
#include <linux/if_addr.h>
#include <linux/if_link.h>
#include <linux/if_packet.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <linux/types.h>
#include <net/ethernet.h>
#include <netinet/in.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <unistd.h>

#include "config.h"
#include "nl.h"
#include "macro.h"
#include "netns_ifaddrs.h"

#ifndef NETNS_RTA
#define NETNS_RTA(r) \
	((struct rtattr *)(((char *)(r)) + NLMSG_ALIGN(sizeof(struct rtgenmsg))))
#endif

#define IFADDRS_HASH_SIZE 64

#define __NETLINK_ALIGN(len) (((len) + 3) & ~3)

#define __NLMSG_OK(nlh, end) \
	((size_t)((char *)(end) - (char *)(nlh)) >= sizeof(struct nlmsghdr))

#define __NLMSG_NEXT(nlh) \
	(struct nlmsghdr *)((char *)(nlh) + __NETLINK_ALIGN((nlh)->nlmsg_len))

#define __NLMSG_DATA(nlh) ((void *)((char *)(nlh) + sizeof(struct nlmsghdr)))

#define __NLMSG_DATAEND(nlh) ((char *)(nlh) + (nlh)->nlmsg_len)

#define __NLMSG_RTA(nlh, len)                               \
	((void *)((char *)(nlh) + sizeof(struct nlmsghdr) + \
		  __NETLINK_ALIGN(len)))

#define __RTA_DATALEN(rta) ((rta)->rta_len - sizeof(struct rtattr))

#define __RTA_NEXT(rta) \
	(struct rtattr *)((char *)(rta) + __NETLINK_ALIGN((rta)->rta_len))

#define __RTA_OK(nlh, end) \
	((size_t)((char *)(end) - (char *)(rta)) >= sizeof(struct rtattr))

#define __NLMSG_RTAOK(rta, nlh) __RTA_OK(rta, __NLMSG_DATAEND(nlh))

#define __IN6_IS_ADDR_LINKLOCAL(a) \
	((((uint8_t *)(a))[0]) == 0xfe && (((uint8_t *)(a))[1] & 0xc0) == 0x80)

#define __IN6_IS_ADDR_MC_LINKLOCAL(a) \
	(IN6_IS_ADDR_MULTICAST(a) && ((((uint8_t *)(a))[1] & 0xf) == 0x2))

#define __RTA_DATA(rta) ((void *)((char *)(rta) + sizeof(struct rtattr)))

/* getifaddrs() reports hardware addresses with PF_PACKET that implies struct
 * sockaddr_ll.  But e.g. Infiniband socket address length is longer than
 * sockaddr_ll.ssl_addr[8] can hold. Use this hack struct to extend ssl_addr -
 * callers should be able to still use it.
 */
struct sockaddr_ll_hack {
	unsigned short sll_family, sll_protocol;
	int sll_ifindex;
	unsigned short sll_hatype;
	unsigned char sll_pkttype, sll_halen;
	unsigned char sll_addr[24];
};

union sockany {
	struct sockaddr sa;
	struct sockaddr_ll_hack ll;
	struct sockaddr_in v4;
	struct sockaddr_in6 v6;
};

struct ifaddrs_storage {
	struct netns_ifaddrs ifa;
	struct ifaddrs_storage *hash_next;
	union sockany addr, netmask, ifu;
	unsigned int index;
	char name[IFNAMSIZ + 1];
};

struct ifaddrs_ctx {
	struct ifaddrs_storage *first;
	struct ifaddrs_storage *last;
	struct ifaddrs_storage *hash[IFADDRS_HASH_SIZE];
};

static void copy_addr(struct sockaddr **r, int af, union sockany *sa,
		      void *addr, size_t addrlen, int ifindex)
{
	uint8_t *dst;
	size_t len;

	switch (af) {
	case AF_INET:
		dst = (uint8_t *)&sa->v4.sin_addr;
		len = 4;
		break;
	case AF_INET6:
		dst = (uint8_t *)&sa->v6.sin6_addr;
		len = 16;
		if (__IN6_IS_ADDR_LINKLOCAL(addr) ||
		    __IN6_IS_ADDR_MC_LINKLOCAL(addr))
			sa->v6.sin6_scope_id = ifindex;
		break;
	default:
		return;
	}

	if (addrlen < len)
		return;

	sa->sa.sa_family = af;

	memcpy(dst, addr, len);

	*r = &sa->sa;
}

static void gen_netmask(struct sockaddr **r, int af, union sockany *sa,
			int prefixlen)
{
	uint8_t addr[16] = {0};
	int i;

	if ((size_t)prefixlen > 8 * sizeof(addr))
		prefixlen = 8 * sizeof(addr);

	i = prefixlen / 8;

	memset(addr, 0xff, i);

	if ((size_t)i < sizeof(addr))
		addr[i++] = 0xff << (8 - (prefixlen % 8));

	copy_addr(r, af, sa, addr, sizeof(addr), 0);
}

static void copy_lladdr(struct sockaddr **r, union sockany *sa, void *addr,
			size_t addrlen, int ifindex, unsigned short hatype)
{
	if (addrlen > sizeof(sa->ll.sll_addr))
		return;

	sa->ll.sll_family = AF_PACKET;
	sa->ll.sll_ifindex = ifindex;
	sa->ll.sll_hatype = hatype;
	sa->ll.sll_halen = addrlen;

	memcpy(sa->ll.sll_addr, addr, addrlen);

	*r = &sa->sa;
}

static int nl_msg_to_ifaddr(void *pctx, bool *netnsid_aware, struct nlmsghdr *h)
{
	struct ifaddrs_storage *ifs, *ifs0;
	struct rtattr *rta;
	int stats_len = 0;
	struct ifinfomsg *ifi = __NLMSG_DATA(h);
	struct ifaddrmsg *ifa = __NLMSG_DATA(h);
	struct ifaddrs_ctx *ctx = pctx;

	if (h->nlmsg_type == RTM_NEWLINK) {
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wcast-align"
		for (rta = __NLMSG_RTA(h, sizeof(*ifi)); __NLMSG_RTAOK(rta, h);
		     rta = __RTA_NEXT(rta)) {
#if HAVE_STRUCT_RTNL_LINK_STATS64
			if (rta->rta_type != IFLA_STATS64)
#else
			if (rta->rta_type != IFLA_STATS)
#endif
				continue;

			stats_len = __RTA_DATALEN(rta);
			break;
		}
#pragma GCC diagnostic pop
	} else {
		for (ifs0 = ctx->hash[ifa->ifa_index % IFADDRS_HASH_SIZE]; ifs0;
		     ifs0 = ifs0->hash_next)
			if (ifs0->index == ifa->ifa_index)
				break;
		if (!ifs0)
			return 0;
	}

	ifs = calloc(1, sizeof(struct ifaddrs_storage) + stats_len);
	if (!ifs) {
		errno = ENOMEM;
		return -1;
	}

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wcast-align"
	if (h->nlmsg_type == RTM_NEWLINK) {
		ifs->index = ifi->ifi_index;
		ifs->ifa.ifa_ifindex = ifi->ifi_index;
		ifs->ifa.ifa_flags = ifi->ifi_flags;

		for (rta = __NLMSG_RTA(h, sizeof(*ifi)); __NLMSG_RTAOK(rta, h);
		     rta = __RTA_NEXT(rta)) {
			switch (rta->rta_type) {
			case IFLA_IFNAME:
				if (__RTA_DATALEN(rta) < sizeof(ifs->name)) {
					memcpy(ifs->name, __RTA_DATA(rta),
					       __RTA_DATALEN(rta));
					ifs->ifa.ifa_name = ifs->name;
				}
				break;
			case IFLA_ADDRESS:
				copy_lladdr(&ifs->ifa.ifa_addr, &ifs->addr,
					    __RTA_DATA(rta), __RTA_DATALEN(rta),
					    ifi->ifi_index, ifi->ifi_type);
				break;
			case IFLA_BROADCAST:
				copy_lladdr(&ifs->ifa.__ifa_broadaddr, &ifs->ifu,
					    __RTA_DATA(rta), __RTA_DATALEN(rta),
					    ifi->ifi_index, ifi->ifi_type);
				break;
#if HAVE_STRUCT_RTNL_LINK_STATS64
			case IFLA_STATS64:
				ifs->ifa.ifa_stats_type = IFLA_STATS64;
#else
			case IFLA_STATS:
				ifs->ifa.ifa_stats_type = IFLA_STATS;
#endif
				memcpy(&ifs->ifa.ifa_stats, __RTA_DATA(rta),
				       __RTA_DATALEN(rta));
				break;
			case IFLA_MTU:
				memcpy(&ifs->ifa.ifa_mtu, __RTA_DATA(rta),
				       sizeof(int));
				break;
			case IFLA_TARGET_NETNSID:
				*netnsid_aware = true;
				break;
			}
		}

		if (ifs->ifa.ifa_name) {
			unsigned int bucket = ifs->index % IFADDRS_HASH_SIZE;
			ifs->hash_next = ctx->hash[bucket];
			ctx->hash[bucket] = ifs;
		}
	} else {
		ifs->ifa.ifa_name = ifs0->ifa.ifa_name;
		ifs->ifa.ifa_mtu = ifs0->ifa.ifa_mtu;
		ifs->ifa.ifa_ifindex = ifs0->ifa.ifa_ifindex;
		ifs->ifa.ifa_flags = ifs0->ifa.ifa_flags;

		for (rta = __NLMSG_RTA(h, sizeof(*ifa)); __NLMSG_RTAOK(rta, h);
		     rta = __RTA_NEXT(rta)) {
			switch (rta->rta_type) {
			case IFA_ADDRESS:
				/* If ifa_addr is already set we, received an
				 * IFA_LOCAL before so treat this as
				 * destination address.
				 */
				if (ifs->ifa.ifa_addr)
					copy_addr(&ifs->ifa.__ifa_dstaddr,
						  ifa->ifa_family, &ifs->ifu,
						  __RTA_DATA(rta),
						  __RTA_DATALEN(rta),
						  ifa->ifa_index);
				else
					copy_addr(&ifs->ifa.ifa_addr,
						  ifa->ifa_family, &ifs->addr,
						  __RTA_DATA(rta),
						  __RTA_DATALEN(rta),
						  ifa->ifa_index);
				break;
			case IFA_BROADCAST:
				copy_addr(&ifs->ifa.__ifa_broadaddr,
					  ifa->ifa_family, &ifs->ifu,
					  __RTA_DATA(rta), __RTA_DATALEN(rta),
					  ifa->ifa_index);
				break;
			case IFA_LOCAL:
				/* If ifa_addr is set and we get IFA_LOCAL,
				 * assume we have a point-to-point network.
				 * Move address to correct field.
				 */
				if (ifs->ifa.ifa_addr) {
					ifs->ifu = ifs->addr;
					ifs->ifa.__ifa_dstaddr = &ifs->ifu.sa;

					memset(&ifs->addr, 0, sizeof(ifs->addr));
				}

				copy_addr(&ifs->ifa.ifa_addr, ifa->ifa_family,
					  &ifs->addr, __RTA_DATA(rta),
					  __RTA_DATALEN(rta), ifa->ifa_index);
				break;
			case IFA_LABEL:
				if (__RTA_DATALEN(rta) < sizeof(ifs->name)) {
					memcpy(ifs->name, __RTA_DATA(rta),
					       __RTA_DATALEN(rta));
					ifs->ifa.ifa_name = ifs->name;
				}
				break;
			case IFA_TARGET_NETNSID:
				*netnsid_aware = true;
				break;
			}
		}

		if (ifs->ifa.ifa_addr) {
			gen_netmask(&ifs->ifa.ifa_netmask, ifa->ifa_family,
				    &ifs->netmask, ifa->ifa_prefixlen);
			ifs->ifa.ifa_prefixlen = ifa->ifa_prefixlen;
		}
	}
#pragma GCC diagnostic pop

	if (ifs->ifa.ifa_name) {
		if (!ctx->first)
			ctx->first = ifs;

		if (ctx->last)
			ctx->last->ifa.ifa_next = &ifs->ifa;

		ctx->last = ifs;
	} else {
		free(ifs);
	}

	return 0;
}

static int __ifaddrs_netlink_send(int fd, struct nlmsghdr *nlmsghdr)
{
	int ret;
	struct sockaddr_nl nladdr;
	struct iovec iov = {
	    .iov_base = nlmsghdr,
	    .iov_len = nlmsghdr->nlmsg_len,
	};
	struct msghdr msg = {
	    .msg_name = &nladdr,
	    .msg_namelen = sizeof(nladdr),
	    .msg_iov = &iov,
	    .msg_iovlen = 1,
	};

	memset(&nladdr, 0, sizeof(nladdr));
	nladdr.nl_family = AF_NETLINK;
	nladdr.nl_pid = 0;
	nladdr.nl_groups = 0;

	ret = sendmsg(fd, &msg, MSG_NOSIGNAL);
	if (ret < 0)
		return -1;

	return ret;
}

static int __ifaddrs_netlink_recv(int fd, unsigned int seq, int type, int af,
				  __s32 netns_id, bool *netnsid_aware,
				  int (*cb)(void *ctx, bool *netnsid_aware,
					    struct nlmsghdr *h),
				  void *ctx)
{
	int r, property, ret;
	char *buf;
	struct nlmsghdr *hdr;
	struct ifinfomsg *ifi_msg;
	struct ifaddrmsg *ifa_msg;
	union {
		uint8_t buf[8192];
		struct {
			struct nlmsghdr nlh;
			struct rtgenmsg g;
		} req;
		struct nlmsghdr reply;
	} u;
	char getlink_buf[__NETLINK_ALIGN(sizeof(struct nlmsghdr)) +
			 __NETLINK_ALIGN(sizeof(struct ifinfomsg)) +
			 __NETLINK_ALIGN(1024)] = {0};
	char getaddr_buf[__NETLINK_ALIGN(sizeof(struct nlmsghdr)) +
			 __NETLINK_ALIGN(sizeof(struct ifaddrmsg)) +
			 __NETLINK_ALIGN(1024)] = {0};

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wcast-align"
	if (type == RTM_GETLINK) {
		buf = getlink_buf;
		hdr = (struct nlmsghdr *)buf;
		hdr->nlmsg_len = NLMSG_LENGTH(sizeof(*ifi_msg));

		ifi_msg = (struct ifinfomsg *)__NLMSG_DATA(hdr);
		ifi_msg->ifi_family = af;

		property = IFLA_TARGET_NETNSID;
	} else if (type == RTM_GETADDR) {
		buf = getaddr_buf;
		hdr = (struct nlmsghdr *)buf;
		hdr->nlmsg_len = NLMSG_LENGTH(sizeof(*ifa_msg));

		ifa_msg = (struct ifaddrmsg *)__NLMSG_DATA(hdr);
		ifa_msg->ifa_family = af;

		property = IFA_TARGET_NETNSID;
	} else {
		errno = EINVAL;
		return -1;
	}
#pragma GCC diagnostic pop

	hdr->nlmsg_type = type;
	hdr->nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST;
	hdr->nlmsg_pid = 0;
	hdr->nlmsg_seq = seq;

	if (netns_id >= 0)
		addattr(hdr, 1024, property, &netns_id, sizeof(netns_id));

	r = __ifaddrs_netlink_send(fd, hdr);
	if (r < 0)
		return -1;

	for (;;) {
		r = recv(fd, u.buf, sizeof(u.buf), MSG_DONTWAIT);
		if (r <= 0)
			return -1;

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wcast-align"
		for (hdr = &u.reply; __NLMSG_OK(hdr, (void *)&u.buf[r]);
		     hdr = __NLMSG_NEXT(hdr)) {
			if (hdr->nlmsg_type == NLMSG_DONE)
				return 0;

			if (hdr->nlmsg_type == NLMSG_ERROR) {
				errno = EINVAL;
				return -1;
			}

			ret = cb(ctx, netnsid_aware, hdr);
			if (ret)
				return ret;
		}
#pragma GCC diagnostic pop
	}
}

static int __rtnl_enumerate(int link_af, int addr_af, __s32 netns_id,
			    bool *netnsid_aware,
			    int (*cb)(void *ctx, bool *netnsid_aware, struct nlmsghdr *h),
			    void *ctx)
{
	int fd, r, saved_errno;
	bool getaddr_netnsid_aware = false, getlink_netnsid_aware = false;

	fd = socket(PF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, NETLINK_ROUTE);
	if (fd < 0)
		return -1;

	r = setsockopt(fd, SOL_NETLINK, NETLINK_GET_STRICT_CHK, &(int){1},
		       sizeof(int));
	if (r < 0 && netns_id >= 0) {
		close(fd);
		*netnsid_aware = false;
		return -1;
	}

	r = __ifaddrs_netlink_recv(fd, 1, RTM_GETLINK, link_af, netns_id,
				   &getlink_netnsid_aware, cb, ctx);
	if (!r)
		r = __ifaddrs_netlink_recv(fd, 2, RTM_GETADDR, addr_af, netns_id,
					   &getaddr_netnsid_aware, cb, ctx);

	saved_errno = errno;
	close(fd);
	errno = saved_errno;

	if (getaddr_netnsid_aware && getlink_netnsid_aware)
		*netnsid_aware = true;
	else
		*netnsid_aware = false;

	return r;
}

void netns_freeifaddrs(struct netns_ifaddrs *ifp)
{
	struct netns_ifaddrs *n;

	while (ifp) {
		n = ifp->ifa_next;
		free(ifp);
		ifp = n;
	}
}

int netns_getifaddrs(struct netns_ifaddrs **ifap, __s32 netns_id,
		     bool *netnsid_aware)
{
	int r, saved_errno;
	struct ifaddrs_ctx _ctx;
	struct ifaddrs_ctx *ctx = &_ctx;

	memset(ctx, 0, sizeof *ctx);

	r = __rtnl_enumerate(AF_UNSPEC, AF_UNSPEC, netns_id, netnsid_aware,
			     nl_msg_to_ifaddr, ctx);
	saved_errno = errno;
	if (r < 0)
		netns_freeifaddrs(&ctx->first->ifa);
	else
		*ifap = &ctx->first->ifa;
	errno = saved_errno;

	return r;
}
Commit	Line	Data
cc6119a0	1	#include <arpa/inet.h>
4ba0d9af	2	#include <errno.h>
cc6119a0 CB	3	#include <linux/if.h>
	4	#include <linux/if_addr.h>
	5	#include <linux/if_link.h>
	6	#include <linux/if_packet.h>
4ba0d9af SG	7	#include <linux/netlink.h>
4ba0d9af SG	8	#include <linux/rtnetlink.h>
cc6119a0 CB	9	#include <linux/types.h>
cc6119a0 CB	10	#include <net/ethernet.h>
59e9eabe	11	#include <netinet/in.h>
cc6119a0 CB	12	#include <stdbool.h>
cc6119a0 CB	13	#include <stdio.h>
59e9eabe CB	14	#include <stdlib.h>
	15	#include <string.h>
	16	#include <sys/socket.h>
	17	#include <unistd.h>
4ba0d9af	18
a3aba110	19	#include "config.h"
cc6119a0 CB	20	#include "nl.h"
	21	#include "macro.h"
	22	#include "netns_ifaddrs.h"
	23
	24	#ifndef NETNS_RTA
	25	#define NETNS_RTA(r) \
	26	((struct rtattr )(((char )(r)) + NLMSG_ALIGN(sizeof(struct rtgenmsg))))
	27	#endif
4ba0d9af	28
59e9eabe	29	#define IFADDRS_HASH_SIZE 64
4ba0d9af	30
59e9eabe	31	#define __NETLINK_ALIGN(len) (((len) + 3) & ~3)
4ba0d9af	32
59e9eabe	33	#define __NLMSG_OK(nlh, end) \
49bdee73	34	((size_t)((char )(end) - (char )(nlh)) >= sizeof(struct nlmsghdr))
4ba0d9af	35
59e9eabe CB	36	#define __NLMSG_NEXT(nlh) \
59e9eabe CB	37	(struct nlmsghdr )((char )(nlh) + __NETLINK_ALIGN((nlh)->nlmsg_len))
4ba0d9af	38
59e9eabe	39	#define __NLMSG_DATA(nlh) ((void )((char )(nlh) + sizeof(struct nlmsghdr)))
4ba0d9af	40
59e9eabe	41	#define __NLMSG_DATAEND(nlh) ((char *)(nlh) + (nlh)->nlmsg_len)
4ba0d9af	42
59e9eabe CB	43	#define __NLMSG_RTA(nlh, len) \
	44	((void )((char )(nlh) + sizeof(struct nlmsghdr) + \
	45	__NETLINK_ALIGN(len)))
4ba0d9af	46
59e9eabe CB	47	#define __RTA_DATALEN(rta) ((rta)->rta_len - sizeof(struct rtattr))
	48
	49	#define __RTA_NEXT(rta) \
	50	(struct rtattr )((char )(rta) + __NETLINK_ALIGN((rta)->rta_len))
	51
	52	#define __RTA_OK(nlh, end) \
49bdee73	53	((size_t)((char )(end) - (char )(rta)) >= sizeof(struct rtattr))
59e9eabe CB	54
	55	#define __NLMSG_RTAOK(rta, nlh) __RTA_OK(rta, __NLMSG_DATAEND(nlh))
	56
	57	#define __IN6_IS_ADDR_LINKLOCAL(a) \
	58	((((uint8_t )(a))[0]) == 0xfe && (((uint8_t )(a))[1] & 0xc0) == 0x80)
	59
	60	#define __IN6_IS_ADDR_MC_LINKLOCAL(a) \
	61	(IN6_IS_ADDR_MULTICAST(a) && ((((uint8_t *)(a))[1] & 0xf) == 0x2))
	62
	63	#define __RTA_DATA(rta) ((void )((char )(rta) + sizeof(struct rtattr)))
4ba0d9af	64
cc6119a0 CB	65	/* getifaddrs() reports hardware addresses with PF_PACKET that implies struct
	66	* sockaddr_ll. But e.g. Infiniband socket address length is longer than
	67	* sockaddr_ll.ssl_addr[8] can hold. Use this hack struct to extend ssl_addr -
	68	* callers should be able to still use it.
	69	*/
59e9eabe CB	70	struct sockaddr_ll_hack {
	71	unsigned short sll_family, sll_protocol;
	72	int sll_ifindex;
	73	unsigned short sll_hatype;
	74	unsigned char sll_pkttype, sll_halen;
	75	unsigned char sll_addr[24];
	76	};
	77
	78	union sockany {
	79	struct sockaddr sa;
	80	struct sockaddr_ll_hack ll;
	81	struct sockaddr_in v4;
	82	struct sockaddr_in6 v6;
	83	};
	84
	85	struct ifaddrs_storage {
cc6119a0	86	struct netns_ifaddrs ifa;
59e9eabe CB	87	struct ifaddrs_storage *hash_next;
	88	union sockany addr, netmask, ifu;
	89	unsigned int index;
	90	char name[IFNAMSIZ + 1];
	91	};
	92
	93	struct ifaddrs_ctx {
	94	struct ifaddrs_storage *first;
	95	struct ifaddrs_storage *last;
	96	struct ifaddrs_storage *hash[IFADDRS_HASH_SIZE];
	97	};
	98
59e9eabe CB	99	static void copy_addr(struct sockaddr *r, int af, union sockany sa,
59e9eabe CB	100	void *addr, size_t addrlen, int ifindex)
4ba0d9af	101	{
59e9eabe CB	102	uint8_t *dst;
	103	size_t len;
	104
	105	switch (af) {
	106	case AF_INET:
	107	dst = (uint8_t *)&sa->v4.sin_addr;
	108	len = 4;
	109	break;
	110	case AF_INET6:
	111	dst = (uint8_t *)&sa->v6.sin6_addr;
	112	len = 16;
cc6119a0 CB	113	if (__IN6_IS_ADDR_LINKLOCAL(addr) \|\|
cc6119a0 CB	114	__IN6_IS_ADDR_MC_LINKLOCAL(addr))
59e9eabe CB	115	sa->v6.sin6_scope_id = ifindex;
	116	break;
	117	default:
	118	return;
	119	}
	120
	121	if (addrlen < len)
	122	return;
	123
	124	sa->sa.sa_family = af;
	125
	126	memcpy(dst, addr, len);
	127
	128	*r = &sa->sa;
4ba0d9af SG	129	}
4ba0d9af SG	130
59e9eabe CB	131	static void gen_netmask(struct sockaddr *r, int af, union sockany sa,
59e9eabe CB	132	int prefixlen)
4ba0d9af	133	{
59e9eabe CB	134	uint8_t addr[16] = {0};
	135	int i;
	136
	137	if ((size_t)prefixlen > 8 * sizeof(addr))
	138	prefixlen = 8 * sizeof(addr);
	139
	140	i = prefixlen / 8;
	141
	142	memset(addr, 0xff, i);
	143
	144	if ((size_t)i < sizeof(addr))
	145	addr[i++] = 0xff << (8 - (prefixlen % 8));
	146
	147	copy_addr(r, af, sa, addr, sizeof(addr), 0);
4ba0d9af SG	148	}
4ba0d9af SG	149
59e9eabe CB	150	static void copy_lladdr(struct sockaddr *r, union sockany sa, void *addr,
59e9eabe CB	151	size_t addrlen, int ifindex, unsigned short hatype)
4ba0d9af	152	{
59e9eabe CB	153	if (addrlen > sizeof(sa->ll.sll_addr))
	154	return;
	155
	156	sa->ll.sll_family = AF_PACKET;
	157	sa->ll.sll_ifindex = ifindex;
	158	sa->ll.sll_hatype = hatype;
	159	sa->ll.sll_halen = addrlen;
	160
	161	memcpy(sa->ll.sll_addr, addr, addrlen);
	162
	163	*r = &sa->sa;
4ba0d9af SG	164	}
4ba0d9af SG	165
cc6119a0	166	static int nl_msg_to_ifaddr(void pctx, bool netnsid_aware, struct nlmsghdr *h)
4ba0d9af	167	{
59e9eabe CB	168	struct ifaddrs_storage ifs, ifs0;
	169	struct rtattr *rta;
	170	int stats_len = 0;
	171	struct ifinfomsg *ifi = __NLMSG_DATA(h);
	172	struct ifaddrmsg *ifa = __NLMSG_DATA(h);
	173	struct ifaddrs_ctx *ctx = pctx;
	174
	175	if (h->nlmsg_type == RTM_NEWLINK) {
6ce39620 CB	176	#pragma GCC diagnostic push
6ce39620 CB	177	#pragma GCC diagnostic ignored "-Wcast-align"
59e9eabe CB	178	for (rta = __NLMSG_RTA(h, sizeof(*ifi)); __NLMSG_RTAOK(rta, h);
59e9eabe CB	179	rta = __RTA_NEXT(rta)) {
da5efb6f CB	180	#if HAVE_STRUCT_RTNL_LINK_STATS64
	181	if (rta->rta_type != IFLA_STATS64)
	182	#else
59e9eabe	183	if (rta->rta_type != IFLA_STATS)
da5efb6f	184	#endif
59e9eabe CB	185	continue;
	186
	187	stats_len = __RTA_DATALEN(rta);
	188	break;
	189	}
6ce39620	190	#pragma GCC diagnostic pop
59e9eabe CB	191	} else {
	192	for (ifs0 = ctx->hash[ifa->ifa_index % IFADDRS_HASH_SIZE]; ifs0;
	193	ifs0 = ifs0->hash_next)
	194	if (ifs0->index == ifa->ifa_index)
	195	break;
	196	if (!ifs0)
	197	return 0;
	198	}
	199
	200	ifs = calloc(1, sizeof(struct ifaddrs_storage) + stats_len);
	201	if (!ifs) {
	202	errno = ENOMEM;
	203	return -1;
	204	}
	205
6ce39620 CB	206	#pragma GCC diagnostic push
6ce39620 CB	207	#pragma GCC diagnostic ignored "-Wcast-align"
59e9eabe CB	208	if (h->nlmsg_type == RTM_NEWLINK) {
59e9eabe CB	209	ifs->index = ifi->ifi_index;
cc6119a0	210	ifs->ifa.ifa_ifindex = ifi->ifi_index;
59e9eabe CB	211	ifs->ifa.ifa_flags = ifi->ifi_flags;
	212
	213	for (rta = __NLMSG_RTA(h, sizeof(*ifi)); __NLMSG_RTAOK(rta, h);
	214	rta = __RTA_NEXT(rta)) {
	215	switch (rta->rta_type) {
	216	case IFLA_IFNAME:
	217	if (__RTA_DATALEN(rta) < sizeof(ifs->name)) {
	218	memcpy(ifs->name, __RTA_DATA(rta),
	219	__RTA_DATALEN(rta));
	220	ifs->ifa.ifa_name = ifs->name;
	221	}
	222	break;
	223	case IFLA_ADDRESS:
	224	copy_lladdr(&ifs->ifa.ifa_addr, &ifs->addr,
	225	__RTA_DATA(rta), __RTA_DATALEN(rta),
	226	ifi->ifi_index, ifi->ifi_type);
	227	break;
	228	case IFLA_BROADCAST:
cc6119a0	229	copy_lladdr(&ifs->ifa.__ifa_broadaddr, &ifs->ifu,
59e9eabe CB	230	__RTA_DATA(rta), __RTA_DATALEN(rta),
	231	ifi->ifi_index, ifi->ifi_type);
	232	break;
da5efb6f CB	233	#if HAVE_STRUCT_RTNL_LINK_STATS64
	234	case IFLA_STATS64:
	235	ifs->ifa.ifa_stats_type = IFLA_STATS64;
da5efb6f	236	#else
59e9eabe	237	case IFLA_STATS:
da5efb6f	238	ifs->ifa.ifa_stats_type = IFLA_STATS;
3ccf815f CB	239	#endif
3ccf815f CB	240	memcpy(&ifs->ifa.ifa_stats, __RTA_DATA(rta),
59e9eabe CB	241	__RTA_DATALEN(rta));
59e9eabe CB	242	break;
cc6119a0 CB	243	case IFLA_MTU:
	244	memcpy(&ifs->ifa.ifa_mtu, __RTA_DATA(rta),
	245	sizeof(int));
	246	break;
	247	case IFLA_TARGET_NETNSID:
	248	*netnsid_aware = true;
	249	break;
59e9eabe CB	250	}
	251	}
	252
	253	if (ifs->ifa.ifa_name) {
	254	unsigned int bucket = ifs->index % IFADDRS_HASH_SIZE;
	255	ifs->hash_next = ctx->hash[bucket];
	256	ctx->hash[bucket] = ifs;
	257	}
	258	} else {
	259	ifs->ifa.ifa_name = ifs0->ifa.ifa_name;
cc6119a0 CB	260	ifs->ifa.ifa_mtu = ifs0->ifa.ifa_mtu;
cc6119a0 CB	261	ifs->ifa.ifa_ifindex = ifs0->ifa.ifa_ifindex;
59e9eabe CB	262	ifs->ifa.ifa_flags = ifs0->ifa.ifa_flags;
	263
	264	for (rta = __NLMSG_RTA(h, sizeof(*ifa)); __NLMSG_RTAOK(rta, h);
	265	rta = __RTA_NEXT(rta)) {
	266	switch (rta->rta_type) {
	267	case IFA_ADDRESS:
	268	/* If ifa_addr is already set we, received an
cc6119a0 CB	269	* IFA_LOCAL before so treat this as
cc6119a0 CB	270	* destination address.
59e9eabe CB	271	*/
59e9eabe CB	272	if (ifs->ifa.ifa_addr)
cc6119a0	273	copy_addr(&ifs->ifa.__ifa_dstaddr,
59e9eabe CB	274	ifa->ifa_family, &ifs->ifu,
	275	__RTA_DATA(rta),
	276	__RTA_DATALEN(rta),
	277	ifa->ifa_index);
	278	else
	279	copy_addr(&ifs->ifa.ifa_addr,
	280	ifa->ifa_family, &ifs->addr,
	281	__RTA_DATA(rta),
	282	__RTA_DATALEN(rta),
	283	ifa->ifa_index);
	284	break;
	285	case IFA_BROADCAST:
cc6119a0	286	copy_addr(&ifs->ifa.__ifa_broadaddr,
59e9eabe CB	287	ifa->ifa_family, &ifs->ifu,
	288	__RTA_DATA(rta), __RTA_DATALEN(rta),
	289	ifa->ifa_index);
	290	break;
	291	case IFA_LOCAL:
	292	/* If ifa_addr is set and we get IFA_LOCAL,
cc6119a0 CB	293	* assume we have a point-to-point network.
cc6119a0 CB	294	* Move address to correct field.
59e9eabe CB	295	*/
	296	if (ifs->ifa.ifa_addr) {
	297	ifs->ifu = ifs->addr;
cc6119a0	298	ifs->ifa.__ifa_dstaddr = &ifs->ifu.sa;
59e9eabe CB	299
	300	memset(&ifs->addr, 0, sizeof(ifs->addr));
	301	}
	302
	303	copy_addr(&ifs->ifa.ifa_addr, ifa->ifa_family,
	304	&ifs->addr, __RTA_DATA(rta),
	305	__RTA_DATALEN(rta), ifa->ifa_index);
	306	break;
	307	case IFA_LABEL:
	308	if (__RTA_DATALEN(rta) < sizeof(ifs->name)) {
	309	memcpy(ifs->name, __RTA_DATA(rta),
	310	__RTA_DATALEN(rta));
	311	ifs->ifa.ifa_name = ifs->name;
	312	}
	313	break;
cc6119a0 CB	314	case IFA_TARGET_NETNSID:
	315	*netnsid_aware = true;
	316	break;
59e9eabe CB	317	}
	318	}
	319
cc6119a0	320	if (ifs->ifa.ifa_addr) {
59e9eabe CB	321	gen_netmask(&ifs->ifa.ifa_netmask, ifa->ifa_family,
59e9eabe CB	322	&ifs->netmask, ifa->ifa_prefixlen);
cc6119a0 CB	323	ifs->ifa.ifa_prefixlen = ifa->ifa_prefixlen;
cc6119a0 CB	324	}
59e9eabe	325	}
6ce39620 CB	326	#pragma GCC diagnostic pop
6ce39620 CB	327
59e9eabe CB	328	if (ifs->ifa.ifa_name) {
	329	if (!ctx->first)
	330	ctx->first = ifs;
	331
	332	if (ctx->last)
	333	ctx->last->ifa.ifa_next = &ifs->ifa;
	334
	335	ctx->last = ifs;
	336	} else {
	337	free(ifs);
	338	}
	339
	340	return 0;
4ba0d9af SG	341	}
4ba0d9af SG	342
cc6119a0 CB	343	static int __ifaddrs_netlink_send(int fd, struct nlmsghdr *nlmsghdr)
	344	{
	345	int ret;
	346	struct sockaddr_nl nladdr;
	347	struct iovec iov = {
	348	.iov_base = nlmsghdr,
	349	.iov_len = nlmsghdr->nlmsg_len,
	350	};
	351	struct msghdr msg = {
	352	.msg_name = &nladdr,
	353	.msg_namelen = sizeof(nladdr),
	354	.msg_iov = &iov,
	355	.msg_iovlen = 1,
	356	};
	357
	358	memset(&nladdr, 0, sizeof(nladdr));
	359	nladdr.nl_family = AF_NETLINK;
	360	nladdr.nl_pid = 0;
	361	nladdr.nl_groups = 0;
	362
	363	ret = sendmsg(fd, &msg, MSG_NOSIGNAL);
	364	if (ret < 0)
	365	return -1;
	366
	367	return ret;
	368	}
	369
	370	static int __ifaddrs_netlink_recv(int fd, unsigned int seq, int type, int af,
	371	__s32 netns_id, bool *netnsid_aware,
	372	int (cb)(void ctx, bool *netnsid_aware,
	373	struct nlmsghdr *h),
	374	void *ctx)
4ba0d9af	375	{
7d60776a	376	int r, property, ret;
cc6119a0 CB	377	char *buf;
	378	struct nlmsghdr *hdr;
	379	struct ifinfomsg *ifi_msg;
	380	struct ifaddrmsg *ifa_msg;
59e9eabe CB	381	union {
	382	uint8_t buf[8192];
	383	struct {
	384	struct nlmsghdr nlh;
	385	struct rtgenmsg g;
	386	} req;
	387	struct nlmsghdr reply;
	388	} u;
7d60776a CB	389	char getlink_buf[__NETLINK_ALIGN(sizeof(struct nlmsghdr)) +
	390	__NETLINK_ALIGN(sizeof(struct ifinfomsg)) +
	391	__NETLINK_ALIGN(1024)] = {0};
	392	char getaddr_buf[__NETLINK_ALIGN(sizeof(struct nlmsghdr)) +
	393	__NETLINK_ALIGN(sizeof(struct ifaddrmsg)) +
	394	__NETLINK_ALIGN(1024)] = {0};
d3d5554a CB	395
	396	#pragma GCC diagnostic push
	397	#pragma GCC diagnostic ignored "-Wcast-align"
7d60776a CB	398	if (type == RTM_GETLINK) {
	399	buf = getlink_buf;
	400	hdr = (struct nlmsghdr *)buf;
	401	hdr->nlmsg_len = NLMSG_LENGTH(sizeof(*ifi_msg));
	402
cc6119a0	403	ifi_msg = (struct ifinfomsg *)__NLMSG_DATA(hdr);
7d60776a	404	ifi_msg->ifi_family = af;
cc6119a0	405
7d60776a CB	406	property = IFLA_TARGET_NETNSID;
	407	} else if (type == RTM_GETADDR) {
	408	buf = getaddr_buf;
	409	hdr = (struct nlmsghdr *)buf;
cc6119a0	410	hdr->nlmsg_len = NLMSG_LENGTH(sizeof(*ifa_msg));
7d60776a CB	411
	412	ifa_msg = (struct ifaddrmsg *)__NLMSG_DATA(hdr);
	413	ifa_msg->ifa_family = af;
	414
	415	property = IFA_TARGET_NETNSID;
	416	} else {
	417	errno = EINVAL;
	418	return -1;
	419	}
d3d5554a	420	#pragma GCC diagnostic pop
cc6119a0 CB	421
	422	hdr->nlmsg_type = type;
	423	hdr->nlmsg_flags = NLM_F_DUMP \| NLM_F_REQUEST;
	424	hdr->nlmsg_pid = 0;
	425	hdr->nlmsg_seq = seq;
cc6119a0 CB	426
	427	if (netns_id >= 0)
	428	addattr(hdr, 1024, property, &netns_id, sizeof(netns_id));
	429
	430	r = __ifaddrs_netlink_send(fd, hdr);
59e9eabe	431	if (r < 0)
cc6119a0	432	return -1;
59e9eabe CB	433
	434	for (;;) {
	435	r = recv(fd, u.buf, sizeof(u.buf), MSG_DONTWAIT);
	436	if (r <= 0)
	437	return -1;
	438
6ce39620 CB	439	#pragma GCC diagnostic push
6ce39620 CB	440	#pragma GCC diagnostic ignored "-Wcast-align"
cc6119a0 CB	441	for (hdr = &u.reply; __NLMSG_OK(hdr, (void *)&u.buf[r]);
	442	hdr = __NLMSG_NEXT(hdr)) {
	443	if (hdr->nlmsg_type == NLMSG_DONE)
59e9eabe CB	444	return 0;
59e9eabe CB	445
cc6119a0	446	if (hdr->nlmsg_type == NLMSG_ERROR) {
59e9eabe CB	447	errno = EINVAL;
	448	return -1;
	449	}
	450
cc6119a0	451	ret = cb(ctx, netnsid_aware, hdr);
59e9eabe CB	452	if (ret)
	453	return ret;
	454	}
6ce39620	455	#pragma GCC diagnostic pop
59e9eabe	456	}
4ba0d9af SG	457	}
4ba0d9af SG	458
cc6119a0 CB	459	static int __rtnl_enumerate(int link_af, int addr_af, __s32 netns_id,
	460	bool *netnsid_aware,
	461	int (cb)(void ctx, bool netnsid_aware, struct nlmsghdr h),
	462	void *ctx)
4ba0d9af	463	{
59e9eabe	464	int fd, r, saved_errno;
cc6119a0	465	bool getaddr_netnsid_aware = false, getlink_netnsid_aware = false;
59e9eabe CB	466
	467	fd = socket(PF_NETLINK, SOCK_RAW \| SOCK_CLOEXEC, NETLINK_ROUTE);
	468	if (fd < 0)
	469	return -1;
	470
c8ca5a43	471	r = setsockopt(fd, SOL_NETLINK, NETLINK_GET_STRICT_CHK, &(int){1},
c6b64720 CB	472	sizeof(int));
	473	if (r < 0 && netns_id >= 0) {
	474	close(fd);
	475	*netnsid_aware = false;
	476	return -1;
	477	}
	478
cc6119a0 CB	479	r = __ifaddrs_netlink_recv(fd, 1, RTM_GETLINK, link_af, netns_id,
cc6119a0 CB	480	&getlink_netnsid_aware, cb, ctx);
59e9eabe	481	if (!r)
cc6119a0 CB	482	r = __ifaddrs_netlink_recv(fd, 2, RTM_GETADDR, addr_af, netns_id,
cc6119a0 CB	483	&getaddr_netnsid_aware, cb, ctx);
59e9eabe CB	484
	485	saved_errno = errno;
	486	close(fd);
	487	errno = saved_errno;
	488
cc6119a0 CB	489	if (getaddr_netnsid_aware && getlink_netnsid_aware)
	490	*netnsid_aware = true;
	491	else
	492	*netnsid_aware = false;
	493
59e9eabe	494	return r;
4ba0d9af SG	495	}
4ba0d9af SG	496
cc6119a0 CB	497	void netns_freeifaddrs(struct netns_ifaddrs *ifp)
	498	{
	499	struct netns_ifaddrs *n;
	500
	501	while (ifp) {
	502	n = ifp->ifa_next;
	503	free(ifp);
	504	ifp = n;
	505	}
	506	}
	507
	508	int netns_getifaddrs(struct netns_ifaddrs **ifap, __s32 netns_id,
	509	bool *netnsid_aware)
4ba0d9af	510	{
59e9eabe CB	511	int r, saved_errno;
	512	struct ifaddrs_ctx _ctx;
	513	struct ifaddrs_ctx *ctx = &_ctx;
4ba0d9af	514
59e9eabe CB	515	memset(ctx, 0, sizeof *ctx);
59e9eabe CB	516
cc6119a0 CB	517	r = __rtnl_enumerate(AF_UNSPEC, AF_UNSPEC, netns_id, netnsid_aware,
cc6119a0 CB	518	nl_msg_to_ifaddr, ctx);
59e9eabe CB	519	saved_errno = errno;
59e9eabe CB	520	if (r < 0)
cc6119a0	521	netns_freeifaddrs(&ctx->first->ifa);
59e9eabe CB	522	else
	523	*ifap = &ctx->first->ifa;
	524	errno = saved_errno;
	525
	526	return r;
4ba0d9af	527	}