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/*
* files.c -- DHCP server file manipulation *
* Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
*/
#include <stdio.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>
#include <ctype.h>
#include <netdb.h>
#include "debug.h"
#include "dhcpd.h"
#include "files.h"
#include "options.h"
#include "leases.h"
/* on these functions, make sure you datatype matches */
static int read_ip(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_str(char *line, void *arg)
{
char **dest = arg;
free(*dest);
*dest = strdup(line);
return 1;
}
static int read_u32(char *line, void *arg)
{
u_int32_t *dest = arg;
char *endptr;
*dest = strtoul(line, &endptr, 0);
return endptr[0] == '\0';
}
static int read_yn(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;
}
/* read a dhcp option and add it to opt_list */
static int read_opt(char *line, void *arg)
{
struct option_set **opt_list = arg;
char *opt, *val, *endptr;
struct dhcp_option *option = NULL;
int retval = 0, length = 0;
char buffer[255];
u_int16_t result_u16;
u_int32_t result_u32;
int i;
if (!(opt = strtok(line, " \t="))) return 0;
for (i = 0; options[i].code; i++)
if (!strcmp(options[i].name, opt))
option = &(options[i]);
if (!option) return 0;
do {
val = strtok(NULL, ", \t");
if (val) {
length = option_lengths[option->flags & TYPE_MASK];
retval = 0;
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;
memcpy(buffer, val, length);
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));
memcpy(buffer, &result_u16, 2);
retval = (endptr[0] == '\0');
break;
case OPTION_S16:
result_u16 = htons(strtol(val, &endptr, 0));
memcpy(buffer, &result_u16, 2);
retval = (endptr[0] == '\0');
break;
case OPTION_U32:
result_u32 = htonl(strtoul(val, &endptr, 0));
memcpy(buffer, &result_u32, 4);
retval = (endptr[0] == '\0');
break;
case OPTION_S32:
result_u32 = htonl(strtol(val, &endptr, 0));
memcpy(buffer, &result_u32, 4);
retval = (endptr[0] == '\0');
break;
default:
break;
}
if (retval)
attach_option(opt_list, option, buffer, length);
};
} while (val && retval && option->flags & OPTION_LIST);
return retval;
}
static struct config_keyword keywords[] = {
/* keyword[14] handler variable address default[20] */
{"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), "/var/lib/misc/udhcpd.leases"},
{"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), ""},
/*ADDME: static lease */
{"", NULL, NULL, ""}
};
int read_config(char *file)
{
FILE *in;
char buffer[80], orig[80], *token, *line;
int i;
for (i = 0; strlen(keywords[i].keyword); i++)
if (strlen(keywords[i].def))
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, 80, in)) {
if (strchr(buffer, '\n')) *(strchr(buffer, '\n')) = '\0';
strncpy(orig, buffer, 80);
if (strchr(buffer, '#')) *(strchr(buffer, '#')) = '\0';
token = buffer + strspn(buffer, " \t");
if (*token == '\0') continue;
line = token + strcspn(token, " \t=");
if (*line == '\0') continue;
*line = '\0';
line++;
/* 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; strlen(keywords[i].keyword); i++)
if (!strcasecmp(token, keywords[i].keyword))
if (!keywords[i].handler(line, keywords[i].var)) {
LOG(LOG_ERR, "unable to parse '%s'", 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 lease_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) {
if (server_config.remaining) {
if (lease_expired(&(leases[i])))
lease_time = 0;
else lease_time = leases[i].expires - curr;
} else lease_time = leases[i].expires;
lease_time = htonl(lease_time);
fwrite(leases[i].chaddr, 16, 1, fp);
fwrite(&(leases[i].yiaddr), 4, 1, fp);
fwrite(&lease_time, 4, 1, fp);
}
}
fclose(fp);
if (server_config.notify_file) {
sprintf(buf, "%s %s", server_config.notify_file, server_config.lease_file);
system(buf);
}
}
void read_leases(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);
}
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