X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=networking%2Fudhcp%2Fleases.c;h=1745fee0338a46c7251014ca76f0a9f68c66b9d4;hb=eb7512984a26baab2db1913c38a7107f745a70ab;hp=add114f6c41f03aa6b2cf6dbeb65a6dce3f874ce;hpb=4e864a36b611f56c6b347be1dace4e5e805a3eb8;p=oweals%2Fbusybox.git diff --git a/networking/udhcp/leases.c b/networking/udhcp/leases.c index add114f6c..1745fee03 100644 --- a/networking/udhcp/leases.c +++ b/networking/udhcp/leases.c @@ -1,55 +1,63 @@ -/* - * leases.c -- tools to manage DHCP leases +/* vi: set sw=4 ts=4: */ +/* + * leases.c -- tools to manage DHCP leases * Russ Dill July 2001 */ -#include -#include -#include -#include -#include - -#include "dhcpd.h" -#include "files.h" -#include "options.h" -#include "leases.h" -#include "arpping.h" #include "common.h" +#include "dhcpd.h" -unsigned char blank_chaddr[] = {[0 ... 15] = 0}; +/* Find the oldest expired lease, NULL if there are no expired leases */ +static struct dhcpOfferedAddr *oldest_expired_lease(void) +{ + struct dhcpOfferedAddr *oldest = NULL; +// TODO: use monotonic_sec() + unsigned long oldest_lease = time(0); + unsigned i; + + for (i = 0; i < server_config.max_leases; i++) + if (oldest_lease > leases[i].expires) { + oldest_lease = leases[i].expires; + oldest = &(leases[i]); + } + return oldest; +} + /* clear every lease out that chaddr OR yiaddr matches and is nonzero */ -void clear_lease(u_int8_t *chaddr, u_int32_t yiaddr) +static void clear_lease(const uint8_t *chaddr, uint32_t yiaddr) { - unsigned int i, j; - - for (j = 0; j < 16 && !chaddr[j]; j++); - + unsigned i, j; + + for (j = 0; j < 16 && !chaddr[j]; j++) + continue; + for (i = 0; i < server_config.max_leases; i++) - if ((j != 16 && !memcmp(leases[i].chaddr, chaddr, 16)) || - (yiaddr && leases[i].yiaddr == yiaddr)) { - memset(&(leases[i]), 0, sizeof(struct dhcpOfferedAddr)); + if ((j != 16 && memcmp(leases[i].chaddr, chaddr, 16) == 0) + || (yiaddr && leases[i].yiaddr == yiaddr) + ) { + memset(&(leases[i]), 0, sizeof(leases[i])); } } /* add a lease into the table, clearing out any old ones */ -struct dhcpOfferedAddr *add_lease(u_int8_t *chaddr, u_int32_t yiaddr, unsigned long lease) +struct dhcpOfferedAddr *add_lease(const uint8_t *chaddr, uint32_t yiaddr, unsigned long lease) { struct dhcpOfferedAddr *oldest; - + /* clean out any old ones */ clear_lease(chaddr, yiaddr); - + oldest = oldest_expired_lease(); - + if (oldest) { memcpy(oldest->chaddr, chaddr, 16); oldest->yiaddr = yiaddr; oldest->expires = time(0) + lease; } - + return oldest; } @@ -58,93 +66,83 @@ struct dhcpOfferedAddr *add_lease(u_int8_t *chaddr, u_int32_t yiaddr, unsigned l int lease_expired(struct dhcpOfferedAddr *lease) { return (lease->expires < (unsigned long) time(0)); -} - - -/* Find the oldest expired lease, NULL if there are no expired leases */ -struct dhcpOfferedAddr *oldest_expired_lease(void) -{ - struct dhcpOfferedAddr *oldest = NULL; - unsigned long oldest_lease = time(0); - unsigned int i; - - - for (i = 0; i < server_config.max_leases; i++) - if (oldest_lease > leases[i].expires) { - oldest_lease = leases[i].expires; - oldest = &(leases[i]); - } - return oldest; - } /* Find the first lease that matches chaddr, NULL if no match */ -struct dhcpOfferedAddr *find_lease_by_chaddr(u_int8_t *chaddr) +struct dhcpOfferedAddr *find_lease_by_chaddr(const uint8_t *chaddr) { - unsigned int i; + unsigned i; for (i = 0; i < server_config.max_leases; i++) - if (!memcmp(leases[i].chaddr, chaddr, 16)) return &(leases[i]); - + if (!memcmp(leases[i].chaddr, chaddr, 16)) + return &(leases[i]); + return NULL; } /* Find the first lease that matches yiaddr, NULL is no match */ -struct dhcpOfferedAddr *find_lease_by_yiaddr(u_int32_t yiaddr) +struct dhcpOfferedAddr *find_lease_by_yiaddr(uint32_t yiaddr) { - unsigned int i; + unsigned i; for (i = 0; i < server_config.max_leases; i++) - if (leases[i].yiaddr == yiaddr) return &(leases[i]); - + if (leases[i].yiaddr == yiaddr) + return &(leases[i]); + return NULL; } /* check is an IP is taken, if it is, add it to the lease table */ -static int check_ip(u_int32_t addr) +static int nobody_responds_to_arp(uint32_t addr) { + /* 16 zero bytes */ + static const uint8_t blank_chaddr[16] = { 0 }; + /* = { 0 } helps gcc to put it in rodata, not bss */ + struct in_addr temp; + int r; + + r = arpping(addr, server_config.server, server_config.arp, server_config.interface); + if (r) + return r; - if (arpping(addr, server_config.server, server_config.arp, server_config.interface) == 0) { - temp.s_addr = addr; - LOG(LOG_INFO, "%s belongs to someone, reserving it for %ld seconds", - inet_ntoa(temp), server_config.conflict_time); - add_lease(blank_chaddr, addr, server_config.conflict_time); - return 1; - } else return 0; + temp.s_addr = addr; + bb_info_msg("%s belongs to someone, reserving it for %u seconds", + inet_ntoa(temp), (unsigned)server_config.conflict_time); + add_lease(blank_chaddr, addr, server_config.conflict_time); + return 0; } -/* find an assignable address, it check_expired is true, we check all the expired leases as well. +/* find an assignable address, if check_expired is true, we check all the expired leases as well. * Maybe this should try expired leases by age... */ -u_int32_t find_address(int check_expired) +uint32_t find_address(int check_expired) { - u_int32_t addr, ret; - struct dhcpOfferedAddr *lease = NULL; - - addr = ntohl(server_config.start); /* addr is in host order here */ - for (;addr <= ntohl(server_config.end); addr++) { + uint32_t addr, ret; + struct dhcpOfferedAddr *lease = NULL; + addr = server_config.start_ip; /* addr is in host order here */ + for (; addr <= server_config.end_ip; addr++) { /* ie, 192.168.55.0 */ - if (!(addr & 0xFF)) continue; - + if (!(addr & 0xFF)) + continue; /* ie, 192.168.55.255 */ - if ((addr & 0xFF) == 0xFF) continue; - - /* lease is not taken */ + if ((addr & 0xFF) == 0xFF) + continue; + /* Only do if it isn't assigned as a static lease */ ret = htonl(addr); - if ((!(lease = find_lease_by_yiaddr(ret)) || - - /* or it expired and we are checking for expired leases */ - (check_expired && lease_expired(lease))) && - - /* and it isn't on the network */ - !check_ip(ret)) { - return ret; - break; + if (!reservedIp(server_config.static_leases, ret)) { + /* lease is not taken */ + lease = find_lease_by_yiaddr(ret); + /* no lease or it expired and we are checking for expired leases */ + if ((!lease || (check_expired && lease_expired(lease))) + && nobody_responds_to_arp(ret) /* it isn't used on the network */ + ) { + return ret; + } } } return 0;