1 /* vi: set sw=4 ts=4: */
3 * DHCP server config and lease file manipulation
5 * Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
7 * Licensed under GPLv2, see file LICENSE in this tarball for details.
9 #include <netinet/ether.h>
15 static inline uint64_t hton64(uint64_t v)
17 return (((uint64_t)htonl(v)) << 32) | htonl(v >> 32);
22 #define ntoh64(v) hton64(v)
24 /* on these functions, make sure your datatype matches */
25 static int FAST_FUNC read_str(const char *line, void *arg)
30 *dest = xstrdup(line);
34 static int FAST_FUNC read_u32(const char *line, void *arg)
36 *(uint32_t*)arg = bb_strtou32(line, NULL, 10);
40 static int FAST_FUNC read_staticlease(const char *const_line, void *arg)
45 struct ether_addr mac_bytes; /* it's "struct { uint8_t mac[6]; }" */
49 line = (char *) const_line;
50 mac_string = strtok_r(line, " \t", &line);
51 if (!mac_string || !ether_aton_r(mac_string, &mac_bytes))
55 ip_string = strtok_r(NULL, " \t", &line);
56 if (!ip_string || !udhcp_str2nip(ip_string, &nip))
59 add_static_lease(arg, (uint8_t*) &mac_bytes, nip);
61 log_static_leases(arg);
67 struct config_keyword {
69 int (*handler)(const char *line, void *var) FAST_FUNC;
74 static const struct config_keyword keywords[] = {
75 /* keyword handler variable address default */
76 {"start" , udhcp_str2nip , &server_config.start_ip , "192.168.0.20"},
77 {"end" , udhcp_str2nip , &server_config.end_ip , "192.168.0.254"},
78 {"interface" , read_str , &server_config.interface , "eth0"},
79 /* Avoid "max_leases value not sane" warning by setting default
80 * to default_end_ip - default_start_ip + 1: */
81 {"max_leases" , read_u32 , &server_config.max_leases , "235"},
82 {"auto_time" , read_u32 , &server_config.auto_time , "7200"},
83 {"decline_time" , read_u32 , &server_config.decline_time , "3600"},
84 {"conflict_time", read_u32 , &server_config.conflict_time, "3600"},
85 {"offer_time" , read_u32 , &server_config.offer_time , "60"},
86 {"min_lease" , read_u32 , &server_config.min_lease_sec, "60"},
87 {"lease_file" , read_str , &server_config.lease_file , LEASES_FILE},
88 {"pidfile" , read_str , &server_config.pidfile , "/var/run/udhcpd.pid"},
89 {"siaddr" , udhcp_str2nip , &server_config.siaddr_nip , "0.0.0.0"},
90 /* keywords with no defaults must be last! */
91 {"option" , udhcp_str2optset, &server_config.options , ""},
92 {"opt" , udhcp_str2optset, &server_config.options , ""},
93 {"notify_file" , read_str , &server_config.notify_file , ""},
94 {"sname" , read_str , &server_config.sname , ""},
95 {"boot_file" , read_str , &server_config.boot_file , ""},
96 {"static_lease" , read_staticlease, &server_config.static_leases, ""},
98 enum { KWS_WITH_DEFAULTS = ARRAY_SIZE(keywords) - 6 };
100 void FAST_FUNC read_config(const char *file)
103 const struct config_keyword *k;
107 for (i = 0; i < KWS_WITH_DEFAULTS; i++)
108 keywords[i].handler(keywords[i].def, keywords[i].var);
110 parser = config_open(file);
111 while (config_read(parser, token, 2, 2, "# \t", PARSE_NORMAL)) {
112 for (k = keywords, i = 0; i < ARRAY_SIZE(keywords); k++, i++) {
113 if (strcasecmp(token[0], k->keyword) == 0) {
114 if (!k->handler(token[1], k->var)) {
115 bb_error_msg("can't parse line %u in %s",
116 parser->lineno, file);
117 /* reset back to the default value */
118 k->handler(k->def, k->var);
124 config_close(parser);
126 server_config.start_ip = ntohl(server_config.start_ip);
127 server_config.end_ip = ntohl(server_config.end_ip);
130 void FAST_FUNC write_leases(void)
137 fd = open_or_warn(server_config.lease_file, O_WRONLY|O_CREAT|O_TRUNC);
141 curr = written_at = time(NULL);
143 written_at = hton64(written_at);
144 full_write(fd, &written_at, sizeof(written_at));
146 for (i = 0; i < server_config.max_leases; i++) {
147 leasetime_t tmp_time;
149 if (g_leases[i].lease_nip == 0)
152 /* Screw with the time in the struct, for easier writing */
153 tmp_time = g_leases[i].expires;
155 g_leases[i].expires -= curr;
156 if ((signed_leasetime_t) g_leases[i].expires < 0)
157 g_leases[i].expires = 0;
158 g_leases[i].expires = htonl(g_leases[i].expires);
160 /* No error check. If the file gets truncated,
161 * we lose some leases on restart. Oh well. */
162 full_write(fd, &g_leases[i], sizeof(g_leases[i]));
164 /* Then restore it when done */
165 g_leases[i].expires = tmp_time;
169 if (server_config.notify_file) {
171 argv[0] = server_config.notify_file;
172 argv[1] = server_config.lease_file;
174 spawn_and_wait(argv);
178 void FAST_FUNC read_leases(const char *file)
180 struct dyn_lease lease;
181 int64_t written_at, time_passed;
183 #if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
187 fd = open_or_warn(file, O_RDONLY);
191 if (full_read(fd, &written_at, sizeof(written_at)) != sizeof(written_at))
193 written_at = ntoh64(written_at);
195 time_passed = time(NULL) - written_at;
196 /* Strange written_at, or lease file from old version of udhcpd
197 * which had no "written_at" field? */
198 if ((uint64_t)time_passed > 12 * 60 * 60)
201 while (full_read(fd, &lease, sizeof(lease)) == sizeof(lease)) {
202 //FIXME: what if it matches some static lease?
203 uint32_t y = ntohl(lease.lease_nip);
204 if (y >= server_config.start_ip && y <= server_config.end_ip) {
205 signed_leasetime_t expires = ntohl(lease.expires) - (signed_leasetime_t)time_passed;
208 /* NB: add_lease takes "relative time", IOW,
209 * lease duration, not lease deadline. */
210 if (add_lease(lease.lease_mac, lease.lease_nip,
212 lease.hostname, sizeof(lease.hostname)
215 bb_error_msg("too many leases while loading %s", file);
218 #if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
223 log1("Read %d leases", i);