1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
|
/* vi: set sw=4 ts=4: */
/*
* DHCP server config and lease file manipulation
*
* Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
*
* Licensed under GPLv2, see file LICENSE in this tarball for details.
*/
#include <netinet/ether.h>
#include "common.h"
#include "dhcpd.h"
#if BB_LITTLE_ENDIAN
static inline uint64_t hton64(uint64_t v)
{
return (((uint64_t)htonl(v)) << 32) | htonl(v >> 32);
}
#else
#define hton64(v) (v)
#endif
#define ntoh64(v) hton64(v)
/* on these functions, make sure your datatype matches */
static int FAST_FUNC read_str(const char *line, void *arg)
{
char **dest = arg;
free(*dest);
*dest = xstrdup(line);
return 1;
}
static int FAST_FUNC read_u32(const char *line, void *arg)
{
*(uint32_t*)arg = bb_strtou32(line, NULL, 10);
return errno == 0;
}
static int FAST_FUNC read_staticlease(const char *const_line, void *arg)
{
char *line;
char *mac_string;
char *ip_string;
struct ether_addr mac_bytes; /* it's "struct { uint8_t mac[6]; }" */
uint32_t nip;
/* Read mac */
line = (char *) const_line;
mac_string = strtok_r(line, " \t", &line);
if (!mac_string || !ether_aton_r(mac_string, &mac_bytes))
return 0;
/* Read ip */
ip_string = strtok_r(NULL, " \t", &line);
if (!ip_string || !udhcp_str2nip(ip_string, &nip))
return 0;
add_static_lease(arg, (uint8_t*) &mac_bytes, nip);
log_static_leases(arg);
return 1;
}
struct config_keyword {
const char *keyword;
int (*handler)(const char *line, void *var) FAST_FUNC;
void *var;
const char *def;
};
static const struct config_keyword keywords[] = {
/* keyword handler variable address default */
{"start" , udhcp_str2nip , &server_config.start_ip , "192.168.0.20"},
{"end" , udhcp_str2nip , &server_config.end_ip , "192.168.0.254"},
{"interface" , read_str , &server_config.interface , "eth0"},
/* Avoid "max_leases value not sane" warning by setting default
* to default_end_ip - default_start_ip + 1: */
{"max_leases" , read_u32 , &server_config.max_leases , "235"},
{"auto_time" , read_u32 , &server_config.auto_time , "7200"},
{"decline_time" , read_u32 , &server_config.decline_time , "3600"},
{"conflict_time", read_u32 , &server_config.conflict_time, "3600"},
{"offer_time" , read_u32 , &server_config.offer_time , "60"},
{"min_lease" , read_u32 , &server_config.min_lease_sec, "60"},
{"lease_file" , read_str , &server_config.lease_file , LEASES_FILE},
{"pidfile" , read_str , &server_config.pidfile , "/var/run/udhcpd.pid"},
{"siaddr" , udhcp_str2nip , &server_config.siaddr_nip , "0.0.0.0"},
/* keywords with no defaults must be last! */
{"option" , udhcp_str2optset, &server_config.options , ""},
{"opt" , udhcp_str2optset, &server_config.options , ""},
{"notify_file" , read_str , &server_config.notify_file , ""},
{"sname" , read_str , &server_config.sname , ""},
{"boot_file" , read_str , &server_config.boot_file , ""},
{"static_lease" , read_staticlease, &server_config.static_leases, ""},
};
enum { KWS_WITH_DEFAULTS = ARRAY_SIZE(keywords) - 6 };
void FAST_FUNC read_config(const char *file)
{
parser_t *parser;
const struct config_keyword *k;
unsigned i;
char *token[2];
for (i = 0; i < KWS_WITH_DEFAULTS; i++)
keywords[i].handler(keywords[i].def, keywords[i].var);
parser = config_open(file);
while (config_read(parser, token, 2, 2, "# \t", PARSE_NORMAL)) {
for (k = keywords, i = 0; i < ARRAY_SIZE(keywords); k++, i++) {
if (strcasecmp(token[0], k->keyword) == 0) {
if (!k->handler(token[1], k->var)) {
bb_error_msg("can't parse line %u in %s",
parser->lineno, file);
/* reset back to the default value */
k->handler(k->def, k->var);
}
break;
}
}
}
config_close(parser);
server_config.start_ip = ntohl(server_config.start_ip);
server_config.end_ip = ntohl(server_config.end_ip);
}
void FAST_FUNC write_leases(void)
{
int fd;
unsigned i;
leasetime_t curr;
int64_t written_at;
fd = open_or_warn(server_config.lease_file, O_WRONLY|O_CREAT|O_TRUNC);
if (fd < 0)
return;
curr = written_at = time(NULL);
written_at = hton64(written_at);
full_write(fd, &written_at, sizeof(written_at));
for (i = 0; i < server_config.max_leases; i++) {
leasetime_t tmp_time;
if (g_leases[i].lease_nip == 0)
continue;
/* Screw with the time in the struct, for easier writing */
tmp_time = g_leases[i].expires;
g_leases[i].expires -= curr;
if ((signed_leasetime_t) g_leases[i].expires < 0)
g_leases[i].expires = 0;
g_leases[i].expires = htonl(g_leases[i].expires);
/* No error check. If the file gets truncated,
* we lose some leases on restart. Oh well. */
full_write(fd, &g_leases[i], sizeof(g_leases[i]));
/* Then restore it when done */
g_leases[i].expires = tmp_time;
}
close(fd);
if (server_config.notify_file) {
char *argv[3];
argv[0] = server_config.notify_file;
argv[1] = server_config.lease_file;
argv[2] = NULL;
spawn_and_wait(argv);
}
}
void FAST_FUNC read_leases(const char *file)
{
struct dyn_lease lease;
int64_t written_at, time_passed;
int fd;
#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
unsigned i = 0;
#endif
fd = open_or_warn(file, O_RDONLY);
if (fd < 0)
return;
if (full_read(fd, &written_at, sizeof(written_at)) != sizeof(written_at))
goto ret;
written_at = ntoh64(written_at);
time_passed = time(NULL) - written_at;
/* Strange written_at, or lease file from old version of udhcpd
* which had no "written_at" field? */
if ((uint64_t)time_passed > 12 * 60 * 60)
goto ret;
while (full_read(fd, &lease, sizeof(lease)) == sizeof(lease)) {
//FIXME: what if it matches some static lease?
uint32_t y = ntohl(lease.lease_nip);
if (y >= server_config.start_ip && y <= server_config.end_ip) {
signed_leasetime_t expires = ntohl(lease.expires) - (signed_leasetime_t)time_passed;
if (expires <= 0)
continue;
/* NB: add_lease takes "relative time", IOW,
* lease duration, not lease deadline. */
if (add_lease(lease.lease_mac, lease.lease_nip,
expires,
lease.hostname, sizeof(lease.hostname)
) == 0
) {
bb_error_msg("too many leases while loading %s", file);
break;
}
#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
i++;
#endif
}
}
log1("Read %d leases", i);
ret:
close(fd);
}
|
