ipaddress.c

busybox最新版的源码:学习和应用的好东东,多的不说了,大家看后再说吧

	h->next = NULL;

	for (lp = linfo; *lp; lp = &(*lp)->next) /* NOTHING */;
	*lp = h;

	ll_remember_index(who, n, NULL);
	return 0;
}

static void ipaddr_reset_filter(int _oneline)
{
	memset(&filter, 0, sizeof(filter));
	filter.oneline = _oneline;
}

/* Return value becomes exitcode. It's okay to not return at all */
int ipaddr_list_or_flush(int argc, char **argv, int flush)
{
	static const char option[] ALIGN1 = "to\0""scope\0""up\0""label\0""dev\0";

	struct nlmsg_list *linfo = NULL;
	struct nlmsg_list *ainfo = NULL;
	struct nlmsg_list *l;
	struct rtnl_handle rth;
	char *filter_dev = NULL;
	int no_link = 0;

	ipaddr_reset_filter(oneline);
	filter.showqueue = 1;

	if (filter.family == AF_UNSPEC)
		filter.family = preferred_family;

	if (flush) {
		if (argc <= 0) {
			bb_error_msg_and_die(bb_msg_requires_arg, "flush");
		}
		if (filter.family == AF_PACKET) {
			bb_error_msg_and_die("cannot flush link addresses");
		}
	}

	while (argc > 0) {
		const int option_num = index_in_strings(option, *argv);
		switch (option_num) {
			case 0: /* to */
				NEXT_ARG();
				get_prefix(&filter.pfx, *argv, filter.family);
				if (filter.family == AF_UNSPEC) {
					filter.family = filter.pfx.family;
				}
				break;
			case 1: /* scope */
			{
				uint32_t scope = 0;
				NEXT_ARG();
				filter.scopemask = -1;
				if (rtnl_rtscope_a2n(&scope, *argv)) {
					if (strcmp(*argv, "all") != 0) {
						invarg(*argv, "scope");
					}
					scope = RT_SCOPE_NOWHERE;
					filter.scopemask = 0;
				}
				filter.scope = scope;
				break;
			}
			case 2: /* up */
				filter.up = 1;
				break;
			case 3: /* label */
				NEXT_ARG();
				filter.label = *argv;
				break;
			case 4: /* dev */
				NEXT_ARG();
			default:
				if (filter_dev) {
					duparg2("dev", *argv);
				}
				filter_dev = *argv;
		}
		argv++;
		argc--;
	}

	xrtnl_open(&rth);

	xrtnl_wilddump_request(&rth, preferred_family, RTM_GETLINK);
	xrtnl_dump_filter(&rth, store_nlmsg, &linfo);

	if (filter_dev) {
		filter.ifindex = xll_name_to_index(filter_dev);
	}

	if (flush) {
		char flushb[4096-512];

		filter.flushb = flushb;
		filter.flushp = 0;
		filter.flushe = sizeof(flushb);
		filter.rth = &rth;

		for (;;) {
			xrtnl_wilddump_request(&rth, filter.family, RTM_GETADDR);
			filter.flushed = 0;
			xrtnl_dump_filter(&rth, print_addrinfo, stdout);
			if (filter.flushed == 0) {
				return 0;
			}
			if (flush_update() < 0)
				return 1;
		}
	}

	if (filter.family != AF_PACKET) {
		xrtnl_wilddump_request(&rth, filter.family, RTM_GETADDR);
		xrtnl_dump_filter(&rth, store_nlmsg, &ainfo);
	}


	if (filter.family && filter.family != AF_PACKET) {
		struct nlmsg_list **lp;
		lp=&linfo;

		if (filter.oneline)
			no_link = 1;

		while ((l=*lp)!=NULL) {
			int ok = 0;
			struct ifinfomsg *ifi = NLMSG_DATA(&l->h);
			struct nlmsg_list *a;

			for (a=ainfo; a; a=a->next) {
				struct nlmsghdr *n = &a->h;
				struct ifaddrmsg *ifa = NLMSG_DATA(n);

				if (ifa->ifa_index != ifi->ifi_index ||
				    (filter.family && filter.family != ifa->ifa_family))
					continue;
				if ((filter.scope^ifa->ifa_scope)&filter.scopemask)
					continue;
				if ((filter.flags^ifa->ifa_flags)&filter.flagmask)
					continue;
				if (filter.pfx.family || filter.label) {
					struct rtattr *tb[IFA_MAX+1];
					memset(tb, 0, sizeof(tb));
					parse_rtattr(tb, IFA_MAX, IFA_RTA(ifa), IFA_PAYLOAD(n));
					if (!tb[IFA_LOCAL])
						tb[IFA_LOCAL] = tb[IFA_ADDRESS];

					if (filter.pfx.family && tb[IFA_LOCAL]) {
						inet_prefix dst;
						memset(&dst, 0, sizeof(dst));
						dst.family = ifa->ifa_family;
						memcpy(&dst.data, RTA_DATA(tb[IFA_LOCAL]), RTA_PAYLOAD(tb[IFA_LOCAL]));
						if (inet_addr_match(&dst, &filter.pfx, filter.pfx.bitlen))
							continue;
					}
					if (filter.label) {
						SPRINT_BUF(b1);
						const char *label;
						if (tb[IFA_LABEL])
							label = RTA_DATA(tb[IFA_LABEL]);
						else
							label = ll_idx_n2a(ifa->ifa_index, b1);
						if (fnmatch(filter.label, label, 0) != 0)
							continue;
					}
				}

				ok = 1;
				break;
			}
			if (!ok)
				*lp = l->next;
			else
				lp = &l->next;
		}
	}

	for (l = linfo; l; l = l->next) {
		if (no_link || print_linkinfo(NULL, &l->h, stdout) == 0) {
			struct ifinfomsg *ifi = NLMSG_DATA(&l->h);
			if (filter.family != AF_PACKET)
				print_selected_addrinfo(ifi->ifi_index, ainfo, stdout);
		}
		fflush(stdout); /* why? */
	}

	return 0;
}

static int default_scope(inet_prefix *lcl)
{
	if (lcl->family == AF_INET) {
		if (lcl->bytelen >= 1 && *(uint8_t*)&lcl->data == 127)
			return RT_SCOPE_HOST;
	}
	return 0;
}

/* Return value becomes exitcode. It's okay to not return at all */
static int ipaddr_modify(int cmd, int argc, char **argv)
{
	static const char option[] ALIGN1 =
		"peer\0""remote\0""broadcast\0""brd\0"
		"anycast\0""scope\0""dev\0""label\0""local\0";
	struct rtnl_handle rth;
	struct {
		struct nlmsghdr  n;
		struct ifaddrmsg ifa;
		char             buf[256];
	} req;
	char *d = NULL;
	char *l = NULL;
	inet_prefix lcl;
	inet_prefix peer;
	int local_len = 0;
	int peer_len = 0;
	int brd_len = 0;
	int any_len = 0;
	bool scoped = 0;

	memset(&req, 0, sizeof(req));

	req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg));
	req.n.nlmsg_flags = NLM_F_REQUEST;
	req.n.nlmsg_type = cmd;
	req.ifa.ifa_family = preferred_family;

	while (argc > 0) {
		const int option_num = index_in_strings(option, *argv);
		switch (option_num) {
			case 0: /* peer */
			case 1: /* remote */
				NEXT_ARG();

				if (peer_len) {
					duparg("peer", *argv);
				}
				get_prefix(&peer, *argv, req.ifa.ifa_family);
				peer_len = peer.bytelen;
				if (req.ifa.ifa_family == AF_UNSPEC) {
					req.ifa.ifa_family = peer.family;
				}
				addattr_l(&req.n, sizeof(req), IFA_ADDRESS, &peer.data, peer.bytelen);
				req.ifa.ifa_prefixlen = peer.bitlen;
				break;
			case 2: /* broadcast */
			case 3: /* brd */
			{
				inet_prefix addr;
				NEXT_ARG();
				if (brd_len) {
					duparg("broadcast", *argv);
				}
				if (LONE_CHAR(*argv, '+')) {
					brd_len = -1;
				}
				else if (LONE_DASH(*argv)) {
					brd_len = -2;
				} else {
					get_addr(&addr, *argv, req.ifa.ifa_family);
					if (req.ifa.ifa_family == AF_UNSPEC)
						req.ifa.ifa_family = addr.family;
					addattr_l(&req.n, sizeof(req), IFA_BROADCAST, &addr.data, addr.bytelen);
					brd_len = addr.bytelen;
				}
				break;
			}
			case 4: /* anycast */
			{
				inet_prefix addr;
				NEXT_ARG();
				if (any_len) {
					duparg("anycast", *argv);
				}
				get_addr(&addr, *argv, req.ifa.ifa_family);
				if (req.ifa.ifa_family == AF_UNSPEC) {
					req.ifa.ifa_family = addr.family;
				}
				addattr_l(&req.n, sizeof(req), IFA_ANYCAST, &addr.data, addr.bytelen);
				any_len = addr.bytelen;
				break;
			}
			case 5: /* scope */
			{
				uint32_t scope = 0;
				NEXT_ARG();
				if (rtnl_rtscope_a2n(&scope, *argv)) {
					invarg(*argv, "scope");
				}
				req.ifa.ifa_scope = scope;
				scoped = 1;
				break;
			}
			case 6: /* dev */
				NEXT_ARG();
				d = *argv;
				break;
			case 7: /* label */
				NEXT_ARG();
				l = *argv;
				addattr_l(&req.n, sizeof(req), IFA_LABEL, l, strlen(l)+1);
				break;
			case 8:	/* local */
				NEXT_ARG();
			default:
				if (local_len) {
					duparg2("local", *argv);
				}
				get_prefix(&lcl, *argv, req.ifa.ifa_family);
				if (req.ifa.ifa_family == AF_UNSPEC) {
					req.ifa.ifa_family = lcl.family;
				}
				addattr_l(&req.n, sizeof(req), IFA_LOCAL, &lcl.data, lcl.bytelen);
				local_len = lcl.bytelen;
		}
		argc--;
		argv++;
	}

	if (d == NULL) {
		bb_error_msg(bb_msg_requires_arg,"\"dev\"");
		return -1;
	}
	if (l && strncmp(d, l, strlen(d)) != 0) {
		bb_error_msg_and_die("\"dev\" (%s) must match \"label\" (%s)", d, l);
	}

	if (peer_len == 0 && local_len && cmd != RTM_DELADDR) {
		peer = lcl;
		addattr_l(&req.n, sizeof(req), IFA_ADDRESS, &lcl.data, lcl.bytelen);
	}
	if (req.ifa.ifa_prefixlen == 0)
		req.ifa.ifa_prefixlen = lcl.bitlen;

	if (brd_len < 0 && cmd != RTM_DELADDR) {
		inet_prefix brd;
		int i;
		if (req.ifa.ifa_family != AF_INET) {
			bb_error_msg_and_die("broadcast can be set only for IPv4 addresses");
		}
		brd = peer;
		if (brd.bitlen <= 30) {
			for (i=31; i>=brd.bitlen; i--) {
				if (brd_len == -1)
					brd.data[0] |= htonl(1<<(31-i));
				else
					brd.data[0] &= ~htonl(1<<(31-i));
			}
			addattr_l(&req.n, sizeof(req), IFA_BROADCAST, &brd.data, brd.bytelen);
			brd_len = brd.bytelen;
		}
	}
	if (!scoped && cmd != RTM_DELADDR)
		req.ifa.ifa_scope = default_scope(&lcl);

	xrtnl_open(&rth);

	ll_init_map(&rth);

	req.ifa.ifa_index = xll_name_to_index(d);

	if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0)
		return 2;

	return 0;
}

/* Return value becomes exitcode. It's okay to not return at all */
int do_ipaddr(int argc, char **argv)
{
	static const char commands[] ALIGN1 =
		"add\0""delete\0""list\0""show\0""lst\0""flush\0";

	int command_num = 2; /* default command is list */

	if (*argv) {
		command_num = index_in_substrings(commands, *argv);
	}
	if (command_num < 0 || command_num > 5)
		bb_error_msg_and_die("unknown command %s", *argv);
	--argc;
	++argv;
	if (command_num == 0) /* add */
		return ipaddr_modify(RTM_NEWADDR, argc, argv);
	else if (command_num == 1) /* delete */
		return ipaddr_modify(RTM_DELADDR, argc, argv);
	else if (command_num == 5) /* flush */
		return ipaddr_list_or_flush(argc, argv, 1);
	else /* 2 == list, 3 == show, 4 == lst */
		return ipaddr_list_or_flush(argc, argv, 0);
}