[1765] | 1 | /* vi: set sw=4 ts=4: */
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[821] | 2 | /*
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[2725] | 3 | * DHCP server config and lease file manipulation
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| 4 | *
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[821] | 5 | * Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
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[2725] | 6 | *
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| 7 | * Licensed under GPLv2, see file LICENSE in this source tree.
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[821] | 8 | */
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| 9 | #include <netinet/ether.h>
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| 10 |
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[1765] | 11 | #include "common.h"
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[821] | 12 | #include "dhcpd.h"
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| 13 |
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[1765] | 14 | /* on these functions, make sure your datatype matches */
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[2725] | 15 | static int FAST_FUNC read_str(const char *line, void *arg)
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[821] | 16 | {
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| 17 | char **dest = arg;
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| 18 |
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| 19 | free(*dest);
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[1765] | 20 | *dest = xstrdup(line);
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[821] | 21 | return 1;
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| 22 | }
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| 23 |
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[2725] | 24 | static int FAST_FUNC read_u32(const char *line, void *arg)
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[821] | 25 | {
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[1765] | 26 | *(uint32_t*)arg = bb_strtou32(line, NULL, 10);
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| 27 | return errno == 0;
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[821] | 28 | }
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| 29 |
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[2725] | 30 | static int FAST_FUNC read_staticlease(const char *const_line, void *arg)
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[821] | 31 | {
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| 32 | char *line;
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| 33 | char *mac_string;
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| 34 | char *ip_string;
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[2725] | 35 | struct ether_addr mac_bytes; /* it's "struct { uint8_t mac[6]; }" */
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| 36 | uint32_t nip;
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[821] | 37 |
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| 38 | /* Read mac */
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| 39 | line = (char *) const_line;
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[2725] | 40 | mac_string = strtok_r(line, " \t", &line);
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| 41 | if (!mac_string || !ether_aton_r(mac_string, &mac_bytes))
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| 42 | return 0;
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[821] | 43 |
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| 44 | /* Read ip */
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[2725] | 45 | ip_string = strtok_r(NULL, " \t", &line);
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| 46 | if (!ip_string || !udhcp_str2nip(ip_string, &nip))
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| 47 | return 0;
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[821] | 48 |
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[2725] | 49 | add_static_lease(arg, (uint8_t*) &mac_bytes, nip);
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[821] | 50 |
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[2725] | 51 | log_static_leases(arg);
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[821] | 52 |
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| 53 | return 1;
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| 54 | }
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| 55 |
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| 56 |
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[1765] | 57 | struct config_keyword {
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| 58 | const char *keyword;
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[2725] | 59 | int (*handler)(const char *line, void *var) FAST_FUNC;
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[1765] | 60 | void *var;
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| 61 | const char *def;
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| 62 | };
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| 63 |
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[821] | 64 | static const struct config_keyword keywords[] = {
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[2725] | 65 | /* keyword handler variable address default */
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| 66 | {"start" , udhcp_str2nip , &server_config.start_ip , "192.168.0.20"},
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| 67 | {"end" , udhcp_str2nip , &server_config.end_ip , "192.168.0.254"},
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| 68 | {"interface" , read_str , &server_config.interface , "eth0"},
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[1765] | 69 | /* Avoid "max_leases value not sane" warning by setting default
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| 70 | * to default_end_ip - default_start_ip + 1: */
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[2725] | 71 | {"max_leases" , read_u32 , &server_config.max_leases , "235"},
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| 72 | {"auto_time" , read_u32 , &server_config.auto_time , "7200"},
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| 73 | {"decline_time" , read_u32 , &server_config.decline_time , "3600"},
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| 74 | {"conflict_time", read_u32 , &server_config.conflict_time, "3600"},
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| 75 | {"offer_time" , read_u32 , &server_config.offer_time , "60"},
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| 76 | {"min_lease" , read_u32 , &server_config.min_lease_sec, "60"},
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| 77 | {"lease_file" , read_str , &server_config.lease_file , LEASES_FILE},
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| 78 | {"pidfile" , read_str , &server_config.pidfile , "/var/run/udhcpd.pid"},
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| 79 | {"siaddr" , udhcp_str2nip , &server_config.siaddr_nip , "0.0.0.0"},
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| 80 | /* keywords with no defaults must be last! */
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| 81 | {"option" , udhcp_str2optset, &server_config.options , ""},
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| 82 | {"opt" , udhcp_str2optset, &server_config.options , ""},
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[3232] | 83 | {"notify_file" , read_str , &server_config.notify_file , NULL},
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| 84 | {"sname" , read_str , &server_config.sname , NULL},
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| 85 | {"boot_file" , read_str , &server_config.boot_file , NULL},
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[2725] | 86 | {"static_lease" , read_staticlease, &server_config.static_leases, ""},
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[821] | 87 | };
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[2725] | 88 | enum { KWS_WITH_DEFAULTS = ARRAY_SIZE(keywords) - 6 };
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[821] | 89 |
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[2725] | 90 | void FAST_FUNC read_config(const char *file)
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[821] | 91 | {
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[2725] | 92 | parser_t *parser;
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| 93 | const struct config_keyword *k;
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| 94 | unsigned i;
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| 95 | char *token[2];
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[821] | 96 |
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[2725] | 97 | for (i = 0; i < KWS_WITH_DEFAULTS; i++)
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| 98 | keywords[i].handler(keywords[i].def, keywords[i].var);
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[821] | 99 |
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[2725] | 100 | parser = config_open(file);
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| 101 | while (config_read(parser, token, 2, 2, "# \t", PARSE_NORMAL)) {
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| 102 | for (k = keywords, i = 0; i < ARRAY_SIZE(keywords); k++, i++) {
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| 103 | if (strcasecmp(token[0], k->keyword) == 0) {
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| 104 | if (!k->handler(token[1], k->var)) {
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| 105 | bb_error_msg("can't parse line %u in %s",
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| 106 | parser->lineno, file);
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[821] | 107 | /* reset back to the default value */
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[2725] | 108 | k->handler(k->def, k->var);
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[821] | 109 | }
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[2725] | 110 | break;
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| 111 | }
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| 112 | }
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[821] | 113 | }
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[2725] | 114 | config_close(parser);
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[1765] | 115 |
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| 116 | server_config.start_ip = ntohl(server_config.start_ip);
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| 117 | server_config.end_ip = ntohl(server_config.end_ip);
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[821] | 118 | }
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| 119 |
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[2725] | 120 | void FAST_FUNC write_leases(void)
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[821] | 121 | {
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[2725] | 122 | int fd;
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[1765] | 123 | unsigned i;
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[2725] | 124 | leasetime_t curr;
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| 125 | int64_t written_at;
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[821] | 126 |
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[2725] | 127 | fd = open_or_warn(server_config.lease_file, O_WRONLY|O_CREAT|O_TRUNC);
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| 128 | if (fd < 0)
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[821] | 129 | return;
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| 130 |
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[2725] | 131 | curr = written_at = time(NULL);
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| 132 |
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| 133 | written_at = SWAP_BE64(written_at);
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| 134 | full_write(fd, &written_at, sizeof(written_at));
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| 135 |
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[821] | 136 | for (i = 0; i < server_config.max_leases; i++) {
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[2725] | 137 | leasetime_t tmp_time;
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[821] | 138 |
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[2725] | 139 | if (g_leases[i].lease_nip == 0)
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| 140 | continue;
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[821] | 141 |
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[2725] | 142 | /* Screw with the time in the struct, for easier writing */
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| 143 | tmp_time = g_leases[i].expires;
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[821] | 144 |
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[2725] | 145 | g_leases[i].expires -= curr;
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| 146 | if ((signed_leasetime_t) g_leases[i].expires < 0)
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| 147 | g_leases[i].expires = 0;
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| 148 | g_leases[i].expires = htonl(g_leases[i].expires);
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| 149 |
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| 150 | /* No error check. If the file gets truncated,
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| 151 | * we lose some leases on restart. Oh well. */
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| 152 | full_write(fd, &g_leases[i], sizeof(g_leases[i]));
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| 153 |
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| 154 | /* Then restore it when done */
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| 155 | g_leases[i].expires = tmp_time;
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[821] | 156 | }
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[2725] | 157 | close(fd);
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[821] | 158 |
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| 159 | if (server_config.notify_file) {
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[2725] | 160 | char *argv[3];
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| 161 | argv[0] = server_config.notify_file;
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| 162 | argv[1] = server_config.lease_file;
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| 163 | argv[2] = NULL;
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| 164 | spawn_and_wait(argv);
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[821] | 165 | }
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| 166 | }
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| 167 |
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[2725] | 168 | void FAST_FUNC read_leases(const char *file)
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[821] | 169 | {
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[2725] | 170 | struct dyn_lease lease;
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| 171 | int64_t written_at, time_passed;
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| 172 | int fd;
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| 173 | #if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
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| 174 | unsigned i = 0;
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| 175 | #endif
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[821] | 176 |
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[2725] | 177 | fd = open_or_warn(file, O_RDONLY);
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| 178 | if (fd < 0)
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[821] | 179 | return;
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| 180 |
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[2725] | 181 | if (full_read(fd, &written_at, sizeof(written_at)) != sizeof(written_at))
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| 182 | goto ret;
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| 183 | written_at = SWAP_BE64(written_at);
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| 184 |
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| 185 | time_passed = time(NULL) - written_at;
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| 186 | /* Strange written_at, or lease file from old version of udhcpd
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| 187 | * which had no "written_at" field? */
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| 188 | if ((uint64_t)time_passed > 12 * 60 * 60)
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| 189 | goto ret;
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| 190 |
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| 191 | while (full_read(fd, &lease, sizeof(lease)) == sizeof(lease)) {
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| 192 | //FIXME: what if it matches some static lease?
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| 193 | uint32_t y = ntohl(lease.lease_nip);
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[1765] | 194 | if (y >= server_config.start_ip && y <= server_config.end_ip) {
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[2725] | 195 | signed_leasetime_t expires = ntohl(lease.expires) - (signed_leasetime_t)time_passed;
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| 196 | if (expires <= 0)
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| 197 | continue;
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| 198 | /* NB: add_lease takes "relative time", IOW,
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| 199 | * lease duration, not lease deadline. */
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| 200 | if (add_lease(lease.lease_mac, lease.lease_nip,
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| 201 | expires,
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| 202 | lease.hostname, sizeof(lease.hostname)
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| 203 | ) == 0
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| 204 | ) {
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[1765] | 205 | bb_error_msg("too many leases while loading %s", file);
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[821] | 206 | break;
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| 207 | }
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[2725] | 208 | #if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
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[821] | 209 | i++;
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[2725] | 210 | #endif
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[821] | 211 | }
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| 212 | }
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[2725] | 213 | log1("Read %d leases", i);
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| 214 | ret:
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| 215 | close(fd);
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[821] | 216 | }
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