diff options
Diffstat (limited to 'networking/udhcp/leases.c')
| -rw-r--r-- | networking/udhcp/leases.c | 211 |
1 files changed, 0 insertions, 211 deletions
diff --git a/networking/udhcp/leases.c b/networking/udhcp/leases.c deleted file mode 100644 index 6642e396d..000000000 --- a/networking/udhcp/leases.c +++ /dev/null @@ -1,211 +0,0 @@ -/* vi: set sw=4 ts=4: */ -/* - * Russ Dill <Russ.Dill@asu.edu> July 2001 - * - * Licensed under GPLv2, see file LICENSE in this source tree. - */ -#include "common.h" -#include "dhcpd.h" - -/* Find the oldest expired lease, NULL if there are no expired leases */ -static struct dyn_lease *oldest_expired_lease(void) -{ - struct dyn_lease *oldest_lease = NULL; - leasetime_t oldest_time = time(NULL); - unsigned i; - - /* Unexpired leases have g_leases[i].expires >= current time - * and therefore can't ever match */ - for (i = 0; i < server_config.max_leases; i++) { - if (g_leases[i].expires == 0 /* empty entry */ - || g_leases[i].expires < oldest_time - ) { - oldest_time = g_leases[i].expires; - oldest_lease = &g_leases[i]; - } - } - return oldest_lease; -} - -/* Clear out all leases with matching nonzero chaddr OR yiaddr. - * If chaddr == NULL, this is a conflict lease. - */ -static void clear_leases(const uint8_t *chaddr, uint32_t yiaddr) -{ - unsigned i; - - for (i = 0; i < server_config.max_leases; i++) { - if ((chaddr && memcmp(g_leases[i].lease_mac, chaddr, 6) == 0) - || (yiaddr && g_leases[i].lease_nip == yiaddr) - ) { - memset(&g_leases[i], 0, sizeof(g_leases[i])); - } - } -} - -/* Add a lease into the table, clearing out any old ones. - * If chaddr == NULL, this is a conflict lease. - */ -struct dyn_lease* FAST_FUNC add_lease( - const uint8_t *chaddr, uint32_t yiaddr, - leasetime_t leasetime, - const char *hostname, int hostname_len) -{ - struct dyn_lease *oldest; - - /* clean out any old ones */ - clear_leases(chaddr, yiaddr); - - oldest = oldest_expired_lease(); - - if (oldest) { - memset(oldest, 0, sizeof(*oldest)); - if (hostname) { - char *p; - - hostname_len++; /* include NUL */ - if (hostname_len > sizeof(oldest->hostname)) - hostname_len = sizeof(oldest->hostname); - p = safe_strncpy(oldest->hostname, hostname, hostname_len); - /* - * Sanitization (s/bad_char/./g). - * The intent is not to allow only "DNS-valid" hostnames, - * but merely make dumpleases output safe for shells to use. - * We accept "0-9A-Za-z._-", all other chars turn to dots. - */ - while (*p) { - if (!isalnum(*p) && *p != '-' && *p != '_') - *p = '.'; - p++; - } - } - if (chaddr) - memcpy(oldest->lease_mac, chaddr, 6); - oldest->lease_nip = yiaddr; - oldest->expires = time(NULL) + leasetime; - } - - return oldest; -} - -/* True if a lease has expired */ -int FAST_FUNC is_expired_lease(struct dyn_lease *lease) -{ - return (lease->expires < (leasetime_t) time(NULL)); -} - -/* Find the first lease that matches MAC, NULL if no match */ -struct dyn_lease* FAST_FUNC find_lease_by_mac(const uint8_t *mac) -{ - unsigned i; - - for (i = 0; i < server_config.max_leases; i++) - if (memcmp(g_leases[i].lease_mac, mac, 6) == 0) - return &g_leases[i]; - - return NULL; -} - -/* Find the first lease that matches IP, NULL is no match */ -struct dyn_lease* FAST_FUNC find_lease_by_nip(uint32_t nip) -{ - unsigned i; - - for (i = 0; i < server_config.max_leases; i++) - if (g_leases[i].lease_nip == nip) - return &g_leases[i]; - - return NULL; -} - -/* Check if the IP is taken; if it is, add it to the lease table */ -static int nobody_responds_to_arp(uint32_t nip, const uint8_t *safe_mac, unsigned arpping_ms) -{ - struct in_addr temp; - int r; - - r = arpping(nip, safe_mac, - server_config.server_nip, - server_config.server_mac, - server_config.interface, - arpping_ms); - if (r) - return r; - - temp.s_addr = nip; - bb_error_msg("%s belongs to someone, reserving it for %u seconds", - inet_ntoa(temp), (unsigned)server_config.conflict_time); - add_lease(NULL, nip, server_config.conflict_time, NULL, 0); - return 0; -} - -/* Find a new usable (we think) address */ -uint32_t FAST_FUNC find_free_or_expired_nip(const uint8_t *safe_mac, unsigned arpping_ms) -{ - uint32_t addr; - struct dyn_lease *oldest_lease = NULL; - -#if ENABLE_FEATURE_UDHCPD_BASE_IP_ON_MAC - uint32_t stop; - unsigned i, hash; - - /* hash hwaddr: use the SDBM hashing algorithm. Seems to give good - * dispersal even with similarly-valued "strings". - */ - hash = 0; - for (i = 0; i < 6; i++) - hash += safe_mac[i] + (hash << 6) + (hash << 16) - hash; - - /* pick a seed based on hwaddr then iterate until we find a free address. */ - addr = server_config.start_ip - + (hash % (1 + server_config.end_ip - server_config.start_ip)); - stop = addr; -#else - addr = server_config.start_ip; -#define stop (server_config.end_ip + 1) -#endif - do { - uint32_t nip; - struct dyn_lease *lease; - - /* ie, 192.168.55.0 */ - if ((addr & 0xff) == 0) - goto next_addr; - /* ie, 192.168.55.255 */ - if ((addr & 0xff) == 0xff) - goto next_addr; - nip = htonl(addr); - /* skip our own address */ - if (nip == server_config.server_nip) - goto next_addr; - /* is this a static lease addr? */ - if (is_nip_reserved(server_config.static_leases, nip)) - goto next_addr; - - lease = find_lease_by_nip(nip); - if (!lease) { -//TODO: DHCP servers do not always sit on the same subnet as clients: should *ping*, not arp-ping! - if (nobody_responds_to_arp(nip, safe_mac, arpping_ms)) - return nip; - } else { - if (!oldest_lease || lease->expires < oldest_lease->expires) - oldest_lease = lease; - } - - next_addr: - addr++; -#if ENABLE_FEATURE_UDHCPD_BASE_IP_ON_MAC - if (addr > server_config.end_ip) - addr = server_config.start_ip; -#endif - } while (addr != stop); - - if (oldest_lease - && is_expired_lease(oldest_lease) - && nobody_responds_to_arp(oldest_lease->lease_nip, safe_mac, arpping_ms) - ) { - return oldest_lease->lease_nip; - } - - return 0; -} |