networking/udhcp/files.c - codeaurora/busybox - Gitiles

 /*
  * files.c -- DHCP server file manipulation *
  * Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
  */

 #include <sys/socket.h>
 #include <arpa/inet.h>
 #include <string.h>
 #include <stdlib.h>
 #include <time.h>
 #include <ctype.h>
 #include <netdb.h>

 #include <netinet/ether.h>
 #include "static_leases.h"

 #include "dhcpd.h"
 #include "options.h"
 #include "files.h"
 #include "common.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)) {
 		if ((host = gethostbyname(line)))
 			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 = strdup(line);

 	return 1;
 }


 static int read_u32(const char *line, void *arg)
 {
 	uint32_t *dest = arg;
 	char *endptr;
 	*dest = strtoul(line, &endptr, 0);
 	return endptr[0] == '\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, struct dhcp_option *option, char *buffer, int length)
 {
 	struct option_set *existing, *new, **curr;

 	/* add it to an existing option */
 	if ((existing = find_option(*opt_list, option->code))) {
 		DEBUG(LOG_INFO, "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(LOG_INFO, "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;
 	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;
 	if (!(opt = strtok(line, " \t="))) return 0;

 	for (option = dhcp_options; option->code; option++)
 		if (!strcasecmp(option->name, opt))
 			break;

 	if (!option->code) return 0;

 	do {
 		if (!(val = strtok(NULL, ", \t"))) 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);

 	if (!(in = fopen(file, "r"))) {
 		LOG(LOG_ERR, "unable to open config file: %s", file);
 		return 0;
 	}

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

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

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

 		/* eat leading whitespace */
 		line = line + strspn(line, " \t=");
 		/* eat trailing whitespace */
 		for (i = strlen(line); i > 0 && isspace(line[i - 1]); 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)) {
 					LOG(LOG_ERR, "Failure parsing line %d of %s", lm, file);
 					DEBUG(LOG_ERR, "unable to 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)
 {
 	FILE *fp;
 	unsigned int i;
 	char buf[255];
 	time_t curr = time(0);
 	unsigned long tmp_time;

 	if (!(fp = fopen(server_config.lease_file, "w"))) {
 		LOG(LOG_ERR, "Unable to 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);
 			fwrite(&leases[i], sizeof(struct dhcpOfferedAddr), 1, fp);

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

 	if (server_config.notify_file) {
 		sprintf(buf, "%s %s", server_config.notify_file, server_config.lease_file);
 		system(buf);
 	}
 }


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

 	if (!(fp = fopen(file, "r"))) {
 		LOG(LOG_ERR, "Unable to open %s for reading", file);
 		return;
 	}

 	while (i < server_config.max_leases && (fread(&lease, sizeof lease, 1, fp) == 1)) {
 		/* 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))) {
 				LOG(LOG_WARNING, "Too many leases while loading %s\n", file);
 				break;
 			}
 			i++;
 		}
 	}
 	DEBUG(LOG_INFO, "Read %d leases", i);
 	fclose(fp);
 }
	/*
	* files.c -- DHCP server file manipulation *
	* Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
	*/

	#include <sys/socket.h>
	#include <arpa/inet.h>
	#include <string.h>
	#include <stdlib.h>
	#include <time.h>
	#include <ctype.h>
	#include <netdb.h>

	#include <netinet/ether.h>
	#include "static_leases.h"

	#include "dhcpd.h"
	#include "options.h"
	#include "files.h"
	#include "common.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)) {
	if ((host = gethostbyname(line)))
	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 = strdup(line);

	return 1;
	}


	static int read_u32(const char line, void arg)
	{
	uint32_t *dest = arg;
	char *endptr;
	*dest = strtoul(line, &endptr, 0);
	return endptr[0] == '\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, struct dhcp_option option, char *buffer, int length)
	{
	struct option_set existing, new, **curr;

	/* add it to an existing option */
	if ((existing = find_option(*opt_list, option->code))) {
	DEBUG(LOG_INFO, "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(LOG_INFO, "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;
	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;
	if (!(opt = strtok(line, " \t="))) return 0;

	for (option = dhcp_options; option->code; option++)
	if (!strcasecmp(option->name, opt))
	break;

	if (!option->code) return 0;

	do {
	if (!(val = strtok(NULL, ", \t"))) 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);

	if (!(in = fopen(file, "r"))) {
	LOG(LOG_ERR, "unable to open config file: %s", file);
	return 0;
	}

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

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

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

	/* eat leading whitespace */
	line = line + strspn(line, " \t=");
	/* eat trailing whitespace */
	for (i = strlen(line); i > 0 && isspace(line[i - 1]); 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)) {
	LOG(LOG_ERR, "Failure parsing line %d of %s", lm, file);
	DEBUG(LOG_ERR, "unable to 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)
	{
	FILE *fp;
	unsigned int i;
	char buf[255];
	time_t curr = time(0);
	unsigned long tmp_time;

	if (!(fp = fopen(server_config.lease_file, "w"))) {
	LOG(LOG_ERR, "Unable to 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);
	fwrite(&leases[i], sizeof(struct dhcpOfferedAddr), 1, fp);

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

	if (server_config.notify_file) {
	sprintf(buf, "%s %s", server_config.notify_file, server_config.lease_file);
	system(buf);
	}
	}


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

	if (!(fp = fopen(file, "r"))) {
	LOG(LOG_ERR, "Unable to open %s for reading", file);
	return;
	}

	while (i < server_config.max_leases && (fread(&lease, sizeof lease, 1, fp) == 1)) {
	/* 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))) {
	LOG(LOG_WARNING, "Too many leases while loading %s\n", file);
	break;
	}
	i++;
	}
	}
	DEBUG(LOG_INFO, "Read %d leases", i);
	fclose(fp);
	}