Diff of /trunk/mkinitrd-magellan/busybox/networking/udhcp/leases.c

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	revision 816 by niro, Fri Apr 24 18:33:46 2009 UTC	revision 987 by niro, Sun May 30 11:40:40 2010 UTC
#	Line 2	Line 2
2	/*	/*
3	* leases.c -- tools to manage DHCP leases	* leases.c -- tools to manage DHCP leases
4	* Russ Dill <Russ.Dill@asu.edu> July 2001	* Russ Dill <Russ.Dill@asu.edu> July 2001
5		*
6		* Licensed under GPLv2, see file LICENSE in this tarball for details.
7	*/	*/
8
9	#include "common.h"	#include "common.h"
#	Line 9	Line 11
11
12
13	/* Find the oldest expired lease, NULL if there are no expired leases */	/* Find the oldest expired lease, NULL if there are no expired leases */
14	static struct dhcpOfferedAddr *oldest_expired_lease(void)	static struct dyn_lease *oldest_expired_lease(void)
15	{	{
16	struct dhcpOfferedAddr *oldest = NULL;	struct dyn_lease *oldest_lease = NULL;
17	// TODO: use monotonic_sec()	leasetime_t oldest_time = time(NULL);
	unsigned long oldest_lease = time(0);
18	unsigned i;	unsigned i;
19
20	for (i = 0; i < server_config.max_leases; i++)	/* Unexpired leases have g_leases[i].expires >= current time
21	if (oldest_lease > leases[i].expires) {	* and therefore can't ever match */
22	oldest_lease = leases[i].expires;	for (i = 0; i < server_config.max_leases; i++) {
23	oldest = &(leases[i]);	if (g_leases[i].expires < oldest_time) {
24		oldest_time = g_leases[i].expires;
25		oldest_lease = &g_leases[i];
26	}	}
27	return oldest;	}
28		return oldest_lease;
29	}	}
30
31
32	/* clear every lease out that chaddr OR yiaddr matches and is nonzero */	/* Clear every lease out that chaddr OR yiaddr matches and is nonzero */
33	static void clear_lease(const uint8_t *chaddr, uint32_t yiaddr)	static void clear_lease(const uint8_t *chaddr, uint32_t yiaddr)
34	{	{
35	unsigned i, j;	unsigned i, j;
#	Line 33  static void clear_lease(const uint8_t *c	Line 37  static void clear_lease(const uint8_t *c
37	for (j = 0; j < 16 && !chaddr[j]; j++)	for (j = 0; j < 16 && !chaddr[j]; j++)
38	continue;	continue;
39
40	for (i = 0; i < server_config.max_leases; i++)	for (i = 0; i < server_config.max_leases; i++) {
41	if ((j != 16 && memcmp(leases[i].chaddr, chaddr, 16) == 0)	if ((j != 16 && memcmp(g_leases[i].lease_mac, chaddr, 6) == 0)
42	|| (yiaddr && leases[i].yiaddr == yiaddr)	|| (yiaddr && g_leases[i].lease_nip == yiaddr)
43	) {	) {
44	memset(&(leases[i]), 0, sizeof(leases[i]));	memset(&g_leases[i], 0, sizeof(g_leases[i]));
45	}	}
46		}
47	}	}
48
49
50	/* add a lease into the table, clearing out any old ones */	/* Add a lease into the table, clearing out any old ones */
51	struct dhcpOfferedAddr* FAST_FUNC add_lease(const uint8_t *chaddr, uint32_t yiaddr, unsigned long lease)	struct dyn_lease* FAST_FUNC add_lease(
52		const uint8_t *chaddr, uint32_t yiaddr,
53		leasetime_t leasetime,
54		const char *hostname, int hostname_len)
55	{	{
56	struct dhcpOfferedAddr *oldest;	struct dyn_lease *oldest;
57
58	/* clean out any old ones */	/* clean out any old ones */
59	clear_lease(chaddr, yiaddr);	clear_lease(chaddr, yiaddr);
#	Line 53  struct dhcpOfferedAddr* FAST_FUNC add_le	Line 61  struct dhcpOfferedAddr* FAST_FUNC add_le
61	oldest = oldest_expired_lease();	oldest = oldest_expired_lease();
62
63	if (oldest) {	if (oldest) {
64	memcpy(oldest->chaddr, chaddr, 16);	oldest->hostname[0] = '\0';
65	oldest->yiaddr = yiaddr;	if (hostname) {
66	oldest->expires = time(0) + lease;	char *p;
67
68		hostname_len++; /* include NUL */
69		if (hostname_len > sizeof(oldest->hostname))
70		hostname_len = sizeof(oldest->hostname);
71		p = safe_strncpy(oldest->hostname, hostname, hostname_len);
72		/* sanitization (s/non-ASCII/^/g) */
73		while (*p) {
74		if (*p < ' ' || *p > 126)
75		*p = '^';
76		p++;
77		}
78		}
79		memcpy(oldest->lease_mac, chaddr, 6);
80		oldest->lease_nip = yiaddr;
81		oldest->expires = time(NULL) + leasetime;
82	}	}
83
84	return oldest;	return oldest;
85	}	}
86
87
88	/* true if a lease has expired */	/* True if a lease has expired */
89	int FAST_FUNC lease_expired(struct dhcpOfferedAddr *lease)	int FAST_FUNC is_expired_lease(struct dyn_lease *lease)
90	{	{
91	return (lease->expires < (unsigned long) time(0));	return (lease->expires < (leasetime_t) time(NULL));
92	}	}
93
94
95	/* Find the first lease that matches chaddr, NULL if no match */	/* Find the first lease that matches MAC, NULL if no match */
96	struct dhcpOfferedAddr* FAST_FUNC find_lease_by_chaddr(const uint8_t *chaddr)	struct dyn_lease* FAST_FUNC find_lease_by_mac(const uint8_t *mac)
97	{	{
98	unsigned i;	unsigned i;
99
100	for (i = 0; i < server_config.max_leases; i++)	for (i = 0; i < server_config.max_leases; i++)
101	if (!memcmp(leases[i].chaddr, chaddr, 16))	if (memcmp(g_leases[i].lease_mac, mac, 6) == 0)
102	return &(leases[i]);	return &g_leases[i];
103
104	return NULL;	return NULL;
105	}	}
106
107
108	/* Find the first lease that matches yiaddr, NULL is no match */	/* Find the first lease that matches IP, NULL is no match */
109	struct dhcpOfferedAddr* FAST_FUNC find_lease_by_yiaddr(uint32_t yiaddr)	struct dyn_lease* FAST_FUNC find_lease_by_nip(uint32_t nip)
110	{	{
111	unsigned i;	unsigned i;
112
113	for (i = 0; i < server_config.max_leases; i++)	for (i = 0; i < server_config.max_leases; i++)
114	if (leases[i].yiaddr == yiaddr)	if (g_leases[i].lease_nip == nip)
115	return &(leases[i]);	return &g_leases[i];
116
117	return NULL;	return NULL;
118	}	}
119
120
121	/* check is an IP is taken, if it is, add it to the lease table */	/* Check if the IP is taken; if it is, add it to the lease table */
122	static int nobody_responds_to_arp(uint32_t addr)	static int nobody_responds_to_arp(uint32_t nip, const uint8_t *safe_mac)
123	{	{
124	/* 16 zero bytes */	/* 16 zero bytes */
125	static const uint8_t blank_chaddr[16] = { 0 };	static const uint8_t blank_chaddr[16] = { 0 };
#	Line 105  static int nobody_responds_to_arp(uint32	Line 128  static int nobody_responds_to_arp(uint32
128	struct in_addr temp;	struct in_addr temp;
129	int r;	int r;
130
131	r = arpping(addr, server_config.server, server_config.arp, server_config.interface);	r = arpping(nip, safe_mac,
132		server_config.server_nip,
133		server_config.server_mac,
134		server_config.interface);
135	if (r)	if (r)
136	return r;	return r;
137
138	temp.s_addr = addr;	temp.s_addr = nip;
139	bb_info_msg("%s belongs to someone, reserving it for %u seconds",	bb_info_msg("%s belongs to someone, reserving it for %u seconds",
140	inet_ntoa(temp), (unsigned)server_config.conflict_time);	inet_ntoa(temp), (unsigned)server_config.conflict_time);
141	add_lease(blank_chaddr, addr, server_config.conflict_time);	add_lease(blank_chaddr, nip, server_config.conflict_time, NULL, 0);
142	return 0;	return 0;
143	}	}
144
145
146	/* find an assignable address, if check_expired is true, we check all the expired leases as well.	/* Find a new usable (we think) address */
147	* Maybe this should try expired leases by age... */	uint32_t FAST_FUNC find_free_or_expired_nip(const uint8_t *safe_mac)
	uint32_t FAST_FUNC find_address(int check_expired)
148	{	{
149	uint32_t addr, ret;	uint32_t addr;
150	struct dhcpOfferedAddr *lease = NULL;	struct dyn_lease *oldest_lease = NULL;
151
152	addr = server_config.start_ip; /* addr is in host order here */	addr = server_config.start_ip; /* addr is in host order here */
153	for (; addr <= server_config.end_ip; addr++) {	for (; addr <= server_config.end_ip; addr++) {
154		uint32_t nip;
155		struct dyn_lease *lease;
156
157	/* ie, 192.168.55.0 */	/* ie, 192.168.55.0 */
158	if (!(addr & 0xFF))	if ((addr & 0xff) == 0)
159	continue;	continue;
160	/* ie, 192.168.55.255 */	/* ie, 192.168.55.255 */
161	if ((addr & 0xFF) == 0xFF)	if ((addr & 0xff) == 0xff)
162	continue;	continue;
163	/* Only do if it isn't assigned as a static lease */	nip = htonl(addr);
164	ret = htonl(addr);	/* is this a static lease addr? */
165	if (!reservedIp(server_config.static_leases, ret)) {	if (is_nip_reserved(server_config.static_leases, nip))
166	/* lease is not taken */	continue;
167	lease = find_lease_by_yiaddr(ret);
168	/* no lease or it expired and we are checking for expired leases */	lease = find_lease_by_nip(nip);
169	if ((!lease || (check_expired && lease_expired(lease)))	if (!lease) {
170	&& nobody_responds_to_arp(ret) /* it isn't used on the network */	if (nobody_responds_to_arp(nip, safe_mac))
171	) {	return nip;
172	return ret;	} else {
173	}	if (!oldest_lease || lease->expires < oldest_lease->expires)
174		oldest_lease = lease;
175	}	}
176	}	}
177
178		if (oldest_lease && is_expired_lease(oldest_lease)
179		&& nobody_responds_to_arp(oldest_lease->lease_nip, safe_mac)
180		) {
181		return oldest_lease->lease_nip;
182		}
183
184	return 0;	return 0;
185	}	}

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