networking/udhcp/files.c

/* vi: set sw=4 ts=4: */
/*
 * files.c -- DHCP server file manipulation *
 * Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
 */

#include <netinet/ether.h>

#include "common.h"
#include "dhcpd.h"
#include "options.h"


/*
 * Domain names may have 254 chars, and string options can be 254
 * chars long. However, 80 bytes will be enough for most, and won't
 * hog up memory. If you have a special application, change it
 */
#define READ_CONFIG_BUF_SIZE 80

/* on these functions, make sure you datatype matches */
static int read_ip(const char *line, void *arg)
{
	struct in_addr *addr = arg;
	struct hostent *host;
	int retval = 1;

	if (!inet_aton(line, addr)) {
		host = gethostbyname(line);
		if (host)
			addr->s_addr = *((unsigned long *) host->h_addr_list[0]);
		else retval = 0;
	}
	return retval;
}

static int read_mac(const char *line, void *arg)
{
	uint8_t *mac_bytes = arg;
	struct ether_addr *temp_ether_addr;
	int retval = 1;

	temp_ether_addr = ether_aton(line);

	if (temp_ether_addr == NULL)
		retval = 0;
	else
		memcpy(mac_bytes, temp_ether_addr, 6);

	return retval;
}


static int read_str(const char *line, void *arg)
{
	char **dest = arg;

	free(*dest);
	*dest = xstrdup(line);

	return 1;
}


static int read_u32(const char *line, void *arg)
{
	*((uint32_t*)arg) = bb_strtou32(line, NULL, 10);
	return errno == 0;
}


static int read_yn(const char *line, void *arg)
{
	char *dest = arg;
	int retval = 1;

	if (!strcasecmp("yes", line))
		*dest = 1;
	else if (!strcasecmp("no", line))
		*dest = 0;
	else retval = 0;

	return retval;
}


/* find option 'code' in opt_list */
struct option_set *find_option(struct option_set *opt_list, char code)
{
	while (opt_list && opt_list->data[OPT_CODE] < code)
		opt_list = opt_list->next;

	if (opt_list && opt_list->data[OPT_CODE] == code) return opt_list;
	else return NULL;
}


/* add an option to the opt_list */
static void attach_option(struct option_set **opt_list,
		const struct dhcp_option *option, char *buffer, int length)
{
	struct option_set *existing, *new, **curr;

	/* add it to an existing option */
	existing = find_option(*opt_list, option->code);
	if (existing) {
		DEBUG("Attaching option %s to existing member of list", option->name);
		if (option->flags & OPTION_LIST) {
			if (existing->data[OPT_LEN] + length <= 255) {
				existing->data = realloc(existing->data,
						existing->data[OPT_LEN] + length + 2);
				memcpy(existing->data + existing->data[OPT_LEN] + 2, buffer, length);
				existing->data[OPT_LEN] += length;
			} /* else, ignore the data, we could put this in a second option in the future */
		} /* else, ignore the new data */
	} else {
		DEBUG("Attaching option %s to list", option->name);

		/* make a new option */
		new = xmalloc(sizeof(struct option_set));
		new->data = xmalloc(length + 2);
		new->data[OPT_CODE] = option->code;
		new->data[OPT_LEN] = length;
		memcpy(new->data + 2, buffer, length);

		curr = opt_list;
		while (*curr && (*curr)->data[OPT_CODE] < option->code)
			curr = &(*curr)->next;

		new->next = *curr;
		*curr = new;
	}
}


/* read a dhcp option and add it to opt_list */
static int read_opt(const char *const_line, void *arg)
{
	struct option_set **opt_list = arg;
	char *opt, *val, *endptr;
	const struct dhcp_option *option;
	int retval = 0, length;
	char buffer[8];
	char *line;
	uint16_t *result_u16 = (uint16_t *) buffer;
	uint32_t *result_u32 = (uint32_t *) buffer;

	/* Cheat, the only const line we'll actually get is "" */
	line = (char *) const_line;
	opt = strtok(line, " \t=");
	if (!opt) return 0;

	option = dhcp_options;
	while (1) {
		if (!option->code)
			return 0;
		if (!strcasecmp(option->name, opt))
			break;
		 option++;
	}

	do {
		val = strtok(NULL, ", \t");
		if (!val) break;
		length = option_lengths[option->flags & TYPE_MASK];
		retval = 0;
		opt = buffer; /* new meaning for variable opt */
		switch (option->flags & TYPE_MASK) {
		case OPTION_IP:
			retval = read_ip(val, buffer);
			break;
		case OPTION_IP_PAIR:
			retval = read_ip(val, buffer);
			if (!(val = strtok(NULL, ", \t/-"))) retval = 0;
			if (retval) retval = read_ip(val, buffer + 4);
			break;
		case OPTION_STRING:
			length = strlen(val);
			if (length > 0) {
				if (length > 254) length = 254;
				opt = val;
				retval = 1;
			}
			break;
		case OPTION_BOOLEAN:
			retval = read_yn(val, buffer);
			break;
		case OPTION_U8:
			buffer[0] = strtoul(val, &endptr, 0);
			retval = (endptr[0] == '\0');
			break;
		case OPTION_U16:
			*result_u16 = htons(strtoul(val, &endptr, 0));
			retval = (endptr[0] == '\0');
			break;
		case OPTION_S16:
			*result_u16 = htons(strtol(val, &endptr, 0));
			retval = (endptr[0] == '\0');
			break;
		case OPTION_U32:
			*result_u32 = htonl(strtoul(val, &endptr, 0));
			retval = (endptr[0] == '\0');
			break;
		case OPTION_S32:
			*result_u32 = htonl(strtol(val, &endptr, 0));
			retval = (endptr[0] == '\0');
			break;
		default:
			break;
		}
		if (retval)
			attach_option(opt_list, option, opt, length);
	} while (retval && option->flags & OPTION_LIST);
	return retval;
}

static int read_staticlease(const char *const_line, void *arg)
{
	char *line;
	char *mac_string;
	char *ip_string;
	uint8_t *mac_bytes;
	uint32_t *ip;


	/* Allocate memory for addresses */
	mac_bytes = xmalloc(sizeof(unsigned char) * 8);
	ip = xmalloc(sizeof(uint32_t));

	/* Read mac */
	line = (char *) const_line;
	mac_string = strtok(line, " \t");
	read_mac(mac_string, mac_bytes);

	/* Read ip */
	ip_string = strtok(NULL, " \t");
	read_ip(ip_string, ip);

	addStaticLease(arg, mac_bytes, ip);

	if (ENABLE_FEATURE_UDHCP_DEBUG) printStaticLeases(arg);

	return 1;
}


static const struct config_keyword keywords[] = {
	/* keyword	handler   variable address		default */
	{"start",	read_ip,  &(server_config.start),	"192.168.0.20"},
	{"end",		read_ip,  &(server_config.end),		"192.168.0.254"},
	{"interface",	read_str, &(server_config.interface),	"eth0"},
	{"option",	read_opt, &(server_config.options),	""},
	{"opt",		read_opt, &(server_config.options),	""},
	{"max_leases",	read_u32, &(server_config.max_leases),	"254"},
	{"remaining",	read_yn,  &(server_config.remaining),	"yes"},
	{"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),	"60"},
	{"lease_file",	read_str, &(server_config.lease_file),	LEASES_FILE},
	{"pidfile",	read_str, &(server_config.pidfile),	"/var/run/udhcpd.pid"},
	{"notify_file", read_str, &(server_config.notify_file),	""},
	{"siaddr",	read_ip,  &(server_config.siaddr),	"0.0.0.0"},
	{"sname",	read_str, &(server_config.sname),	""},
	{"boot_file",	read_str, &(server_config.boot_file),	""},
	{"static_lease",read_staticlease, &(server_config.static_leases),	""},
	/*ADDME: static lease */
	{"",		NULL,	  NULL,				""}
};


int read_config(const char *file)
{
	FILE *in;
	char buffer[READ_CONFIG_BUF_SIZE], *token, *line;
	int i, lm = 0;

	for (i = 0; keywords[i].keyword[0]; i++)
		if (keywords[i].def[0])
			keywords[i].handler(keywords[i].def, keywords[i].var);

	in = fopen(file, "r");
	if (!in) {
		bb_error_msg("cannot open config file: %s", file);
		return 0;
	}

	while (fgets(buffer, READ_CONFIG_BUF_SIZE, in)) {
		char debug_orig[READ_CONFIG_BUF_SIZE];
		char *p;

		lm++;
		p = strchr(buffer, '\n');
		if (p) *p = '\0';
		if (ENABLE_FEATURE_UDHCP_DEBUG) strcpy(debug_orig, buffer);
		p = strchr(buffer, '#');
		if (p) *p = '\0';

		if (!(token = strtok(buffer, " \t"))) continue;
		if (!(line = strtok(NULL, ""))) continue;

		/* eat leading whitespace */
		line = skip_whitespace(line);
		/* eat trailing whitespace */
		i = strlen(line) - 1;
		while (i >= 0 && isspace(line[i]))
			line[i--] = '\0';

		for (i = 0; keywords[i].keyword[0]; i++)
			if (!strcasecmp(token, keywords[i].keyword))
				if (!keywords[i].handler(line, keywords[i].var)) {
					bb_error_msg("cannot parse line %d of %s", lm, file);
					if (ENABLE_FEATURE_UDHCP_DEBUG)
						bb_error_msg("cannot parse '%s'", debug_orig);
					/* reset back to the default value */
					keywords[i].handler(keywords[i].def, keywords[i].var);
				}
	}
	fclose(in);
	return 1;
}


void write_leases(void)
{
	int fp;
	unsigned i;
	time_t curr = time(0);
	unsigned long tmp_time;

	fp = open(server_config.lease_file, O_WRONLY|O_CREAT|O_TRUNC, 0666);
	if (fp < 0) {
		bb_error_msg("cannot open %s for writing", server_config.lease_file);
		return;
	}

	for (i = 0; i < server_config.max_leases; i++) {
		if (leases[i].yiaddr != 0) {

			/* screw with the time in the struct, for easier writing */
			tmp_time = leases[i].expires;

			if (server_config.remaining) {
				if (lease_expired(&(leases[i])))
					leases[i].expires = 0;
				else leases[i].expires -= curr;
			} /* else stick with the time we got */
			leases[i].expires = htonl(leases[i].expires);
			// FIXME: error check??
			full_write(fp, &leases[i], sizeof(leases[i]));

			/* then restore it when done */
			leases[i].expires = tmp_time;
		}
	}
	close(fp);

	if (server_config.notify_file) {
		char *cmd = xasprintf("%s %s", server_config.notify_file, server_config.lease_file);
		system(cmd);
		free(cmd);
	}
}


void read_leases(const char *file)
{
	int fp;
	unsigned int i = 0;
	struct dhcpOfferedAddr lease;

	fp = open(file, O_RDONLY);
	if (fp < 0) {
		bb_error_msg("cannot open %s for reading", file);
		return;
	}

	while (i < server_config.max_leases
	 && full_read(fp, &lease, sizeof(lease)) == sizeof(lease)
	) {
		/* ADDME: is it a static lease */
		if (lease.yiaddr >= server_config.start && lease.yiaddr <= server_config.end) {
			lease.expires = ntohl(lease.expires);
			if (!server_config.remaining) lease.expires -= time(0);
			if (!(add_lease(lease.chaddr, lease.yiaddr, lease.expires))) {
				bb_error_msg("too many leases while loading %s", file);
				break;
			}
			i++;
		}
	}
	DEBUG("Read %d leases", i);
	close(fp);
}
1	/* vi: set sw=4 ts=4: */
2	/*
3	* files.c -- DHCP server file manipulation *
4	* Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
5	*/
6
7	#include <netinet/ether.h>
8
9	#include "common.h"
10	#include "dhcpd.h"
11	#include "options.h"
12
13
14	/*
15	* Domain names may have 254 chars, and string options can be 254
16	* chars long. However, 80 bytes will be enough for most, and won't
17	* hog up memory. If you have a special application, change it
18	*/
19	#define READ_CONFIG_BUF_SIZE 80
20
21	/* on these functions, make sure you datatype matches */
22	static int read_ip(const char line, void arg)
23	{
24	struct in_addr *addr = arg;
25	struct hostent *host;
26	int retval = 1;
27
28	if (!inet_aton(line, addr)) {
29	host = gethostbyname(line);
30	if (host)
31	addr->s_addr = ((unsigned long ) host->h_addr_list[0]);
32	else retval = 0;
33	}
34	return retval;
35	}
36
37	static int read_mac(const char line, void arg)
38	{
39	uint8_t *mac_bytes = arg;
40	struct ether_addr *temp_ether_addr;
41	int retval = 1;
42
43	temp_ether_addr = ether_aton(line);
44
45	if (temp_ether_addr == NULL)
46	retval = 0;
47	else
48	memcpy(mac_bytes, temp_ether_addr, 6);
49
50	return retval;
51	}
52
53
54	static int read_str(const char line, void arg)
55	{
56	char **dest = arg;
57
58	free(*dest);
59	*dest = xstrdup(line);
60
61	return 1;
62	}
63
64
65	static int read_u32(const char line, void arg)
66	{
67	((uint32_t)arg) = bb_strtou32(line, NULL, 10);
68	return errno == 0;
69	}
70
71
72	static int read_yn(const char line, void arg)
73	{
74	char *dest = arg;
75	int retval = 1;
76
77	if (!strcasecmp("yes", line))
78	*dest = 1;
79	else if (!strcasecmp("no", line))
80	*dest = 0;
81	else retval = 0;
82
83	return retval;
84	}
85
86
87	/* find option 'code' in opt_list */
88	struct option_set find_option(struct option_set opt_list, char code)
89	{
90	while (opt_list && opt_list->data[OPT_CODE] < code)
91	opt_list = opt_list->next;
92
93	if (opt_list && opt_list->data[OPT_CODE] == code) return opt_list;
94	else return NULL;
95	}
96
97
98	/* add an option to the opt_list */
99	static void attach_option(struct option_set **opt_list,
100	const struct dhcp_option option, char buffer, int length)
101	{
102	struct option_set existing, new, **curr;
103
104	/* add it to an existing option */
105	existing = find_option(*opt_list, option->code);
106	if (existing) {
107	DEBUG("Attaching option %s to existing member of list", option->name);
108	if (option->flags & OPTION_LIST) {
109	if (existing->data[OPT_LEN] + length <= 255) {
110	existing->data = realloc(existing->data,
111	existing->data[OPT_LEN] + length + 2);
112	memcpy(existing->data + existing->data[OPT_LEN] + 2, buffer, length);
113	existing->data[OPT_LEN] += length;
114	} /* else, ignore the data, we could put this in a second option in the future */
115	} /* else, ignore the new data */
116	} else {
117	DEBUG("Attaching option %s to list", option->name);
118
119	/* make a new option */
120	new = xmalloc(sizeof(struct option_set));
121	new->data = xmalloc(length + 2);
122	new->data[OPT_CODE] = option->code;
123	new->data[OPT_LEN] = length;
124	memcpy(new->data + 2, buffer, length);
125
126	curr = opt_list;
127	while (curr && (curr)->data[OPT_CODE] < option->code)
128	curr = &(*curr)->next;
129
130	new->next = *curr;
131	*curr = new;
132	}
133	}
134
135
136	/* read a dhcp option and add it to opt_list */
137	static int read_opt(const char const_line, void arg)
138	{
139	struct option_set **opt_list = arg;
140	char opt, val, *endptr;
141	const struct dhcp_option *option;
142	int retval = 0, length;
143	char buffer[8];
144	char *line;
145	uint16_t result_u16 = (uint16_t ) buffer;
146	uint32_t result_u32 = (uint32_t ) buffer;
147
148	/* Cheat, the only const line we'll actually get is "" */
149	line = (char *) const_line;
150	opt = strtok(line, " \t=");
151	if (!opt) return 0;
152
153	option = dhcp_options;
154	while (1) {
155	if (!option->code)
156	return 0;
157	if (!strcasecmp(option->name, opt))
158	break;
159	option++;
160	}
161
162	do {
163	val = strtok(NULL, ", \t");
164	if (!val) break;
165	length = option_lengths[option->flags & TYPE_MASK];
166	retval = 0;
167	opt = buffer; /* new meaning for variable opt */
168	switch (option->flags & TYPE_MASK) {
169	case OPTION_IP:
170	retval = read_ip(val, buffer);
171	break;
172	case OPTION_IP_PAIR:
173	retval = read_ip(val, buffer);
174	if (!(val = strtok(NULL, ", \t/-"))) retval = 0;
175	if (retval) retval = read_ip(val, buffer + 4);
176	break;
177	case OPTION_STRING:
178	length = strlen(val);
179	if (length > 0) {
180	if (length > 254) length = 254;
181	opt = val;
182	retval = 1;
183	}
184	break;
185	case OPTION_BOOLEAN:
186	retval = read_yn(val, buffer);
187	break;
188	case OPTION_U8:
189	buffer[0] = strtoul(val, &endptr, 0);
190	retval = (endptr[0] == '\0');
191	break;
192	case OPTION_U16:
193	*result_u16 = htons(strtoul(val, &endptr, 0));
194	retval = (endptr[0] == '\0');
195	break;
196	case OPTION_S16:
197	*result_u16 = htons(strtol(val, &endptr, 0));
198	retval = (endptr[0] == '\0');
199	break;
200	case OPTION_U32:
201	*result_u32 = htonl(strtoul(val, &endptr, 0));
202	retval = (endptr[0] == '\0');
203	break;
204	case OPTION_S32:
205	*result_u32 = htonl(strtol(val, &endptr, 0));
206	retval = (endptr[0] == '\0');
207	break;
208	default:
209	break;
210	}
211	if (retval)
212	attach_option(opt_list, option, opt, length);
213	} while (retval && option->flags & OPTION_LIST);
214	return retval;
215	}
216
217	static int read_staticlease(const char const_line, void arg)
218	{
219	char *line;
220	char *mac_string;
221	char *ip_string;
222	uint8_t *mac_bytes;
223	uint32_t *ip;
224
225
226	/* Allocate memory for addresses */
227	mac_bytes = xmalloc(sizeof(unsigned char) * 8);
228	ip = xmalloc(sizeof(uint32_t));
229
230	/* Read mac */
231	line = (char *) const_line;
232	mac_string = strtok(line, " \t");
233	read_mac(mac_string, mac_bytes);
234
235	/* Read ip */
236	ip_string = strtok(NULL, " \t");
237	read_ip(ip_string, ip);
238
239	addStaticLease(arg, mac_bytes, ip);
240
241	if (ENABLE_FEATURE_UDHCP_DEBUG) printStaticLeases(arg);
242
243	return 1;
244	}
245
246
247	static const struct config_keyword keywords[] = {
248	/* keyword handler variable address default */
249	{"start", read_ip, &(server_config.start), "192.168.0.20"},
250	{"end", read_ip, &(server_config.end), "192.168.0.254"},
251	{"interface", read_str, &(server_config.interface), "eth0"},
252	{"option", read_opt, &(server_config.options), ""},
253	{"opt", read_opt, &(server_config.options), ""},
254	{"max_leases", read_u32, &(server_config.max_leases), "254"},
255	{"remaining", read_yn, &(server_config.remaining), "yes"},
256	{"auto_time", read_u32, &(server_config.auto_time), "7200"},
257	{"decline_time",read_u32, &(server_config.decline_time),"3600"},
258	{"conflict_time",read_u32,&(server_config.conflict_time),"3600"},
259	{"offer_time", read_u32, &(server_config.offer_time), "60"},
260	{"min_lease", read_u32, &(server_config.min_lease), "60"},
261	{"lease_file", read_str, &(server_config.lease_file), LEASES_FILE},
262	{"pidfile", read_str, &(server_config.pidfile), "/var/run/udhcpd.pid"},
263	{"notify_file", read_str, &(server_config.notify_file), ""},
264	{"siaddr", read_ip, &(server_config.siaddr), "0.0.0.0"},
265	{"sname", read_str, &(server_config.sname), ""},
266	{"boot_file", read_str, &(server_config.boot_file), ""},
267	{"static_lease",read_staticlease, &(server_config.static_leases), ""},
268	/ADDME: static lease /
269	{"", NULL, NULL, ""}
270	};
271
272
273	int read_config(const char *file)
274	{
275	FILE *in;
276	char buffer[READ_CONFIG_BUF_SIZE], token, line;
277	int i, lm = 0;
278
279	for (i = 0; keywords[i].keyword[0]; i++)
280	if (keywords[i].def[0])
281	keywords[i].handler(keywords[i].def, keywords[i].var);
282
283	in = fopen(file, "r");
284	if (!in) {
285	bb_error_msg("cannot open config file: %s", file);
286	return 0;
287	}
288
289	while (fgets(buffer, READ_CONFIG_BUF_SIZE, in)) {
290	char debug_orig[READ_CONFIG_BUF_SIZE];
291	char *p;
292
293	lm++;
294	p = strchr(buffer, '\n');
295	if (p) *p = '\0';
296	if (ENABLE_FEATURE_UDHCP_DEBUG) strcpy(debug_orig, buffer);
297	p = strchr(buffer, '#');
298	if (p) *p = '\0';
299
300	if (!(token = strtok(buffer, " \t"))) continue;
301	if (!(line = strtok(NULL, ""))) continue;
302
303	/* eat leading whitespace */
304	line = skip_whitespace(line);
305	/* eat trailing whitespace */
306	i = strlen(line) - 1;
307	while (i >= 0 && isspace(line[i]))
308	line[i--] = '\0';
309
310	for (i = 0; keywords[i].keyword[0]; i++)
311	if (!strcasecmp(token, keywords[i].keyword))
312	if (!keywords[i].handler(line, keywords[i].var)) {
313	bb_error_msg("cannot parse line %d of %s", lm, file);
314	if (ENABLE_FEATURE_UDHCP_DEBUG)
315	bb_error_msg("cannot parse '%s'", debug_orig);
316	/* reset back to the default value */
317	keywords[i].handler(keywords[i].def, keywords[i].var);
318	}
319	}
320	fclose(in);
321	return 1;
322	}
323
324
325	void write_leases(void)
326	{
327	int fp;
328	unsigned i;
329	time_t curr = time(0);
330	unsigned long tmp_time;
331
332	fp = open(server_config.lease_file, O_WRONLY\|O_CREAT\|O_TRUNC, 0666);
333	if (fp < 0) {
334	bb_error_msg("cannot open %s for writing", server_config.lease_file);
335	return;
336	}
337
338	for (i = 0; i < server_config.max_leases; i++) {
339	if (leases[i].yiaddr != 0) {
340
341	/* screw with the time in the struct, for easier writing */
342	tmp_time = leases[i].expires;
343
344	if (server_config.remaining) {
345	if (lease_expired(&(leases[i])))
346	leases[i].expires = 0;
347	else leases[i].expires -= curr;
348	} /* else stick with the time we got */
349	leases[i].expires = htonl(leases[i].expires);
350	// FIXME: error check??
351	full_write(fp, &leases[i], sizeof(leases[i]));
352
353	/* then restore it when done */
354	leases[i].expires = tmp_time;
355	}
356	}
357	close(fp);
358
359	if (server_config.notify_file) {
360	char *cmd = xasprintf("%s %s", server_config.notify_file, server_config.lease_file);
361	system(cmd);
362	free(cmd);
363	}
364	}
365
366
367	void read_leases(const char *file)
368	{
369	int fp;
370	unsigned int i = 0;
371	struct dhcpOfferedAddr lease;
372
373	fp = open(file, O_RDONLY);
374	if (fp < 0) {
375	bb_error_msg("cannot open %s for reading", file);
376	return;
377	}
378
379	while (i < server_config.max_leases
380	&& full_read(fp, &lease, sizeof(lease)) == sizeof(lease)
381	) {
382	/* ADDME: is it a static lease */
383	if (lease.yiaddr >= server_config.start && lease.yiaddr <= server_config.end) {
384	lease.expires = ntohl(lease.expires);
385	if (!server_config.remaining) lease.expires -= time(0);
386	if (!(add_lease(lease.chaddr, lease.yiaddr, lease.expires))) {
387	bb_error_msg("too many leases while loading %s", file);
388	break;
389	}
390	i++;
391	}
392	}
393	DEBUG("Read %d leases", i);
394	close(fp);
395	}