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/*
* 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 "dhcpd.h"
#include "files.h"
#include "options.h"
#include "common.h"
/* 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_str(const char *line, void *arg)
{
char **dest = arg;
if (*dest) free(*dest);
*dest = strdup(line);
return 1;
}
static int read_u32(const char *line, void *arg)
{
u_int32_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;
}
#define READ_CONFIG_BUF_SIZE 512 /* domainname may have 254 chars */
/* read a dhcp option and add it to opt_list */
static int read_opt(const char *const_line, void *arg)
{
char line[READ_CONFIG_BUF_SIZE];
struct option_set **opt_list = arg;
char *opt, *val, *endptr;
struct dhcp_option *option;
int retval = 0, length;
char buffer[256]; /* max opt length */
u_int16_t result_u16;
u_int32_t result_u32;
void *valptr;
if ((opt = strtok(strcpy(line, const_line), " \t="))) {
for (option = options; option->code; option++)
if (!strcasecmp(option->name, opt))
break;
if (option->code) do {
val = strtok(NULL, ", \t");
if(!val)
break;
length = option_lengths[option->flags & TYPE_MASK];
valptr = NULL;
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;
endptr = buffer + length;
endptr[0] = 0;
valptr = val;
}
break;
case OPTION_BOOLEAN:
retval = read_yn(val, buffer);
break;
case OPTION_U8:
buffer[0] = strtoul(val, &endptr, 0);
valptr = buffer;
break;
case OPTION_U16:
result_u16 = htons(strtoul(val, &endptr, 0));
valptr = &result_u16;
break;
case OPTION_S16:
result_u16 = htons(strtol(val, &endptr, 0));
valptr = &result_u16;
break;
case OPTION_U32:
result_u32 = htonl(strtoul(val, &endptr, 0));
valptr = &result_u32;
break;
case OPTION_S32:
result_u32 = htonl(strtol(val, &endptr, 0));
valptr = &result_u32;
break;
default:
retval = 0;
break;
}
if(valptr) {
memcpy(buffer, valptr, length);
retval = (endptr[0] == '\0');
}
if (retval)
attach_option(opt_list, option, buffer, length);
else
break;
} while (option->flags & OPTION_LIST);
}
return retval;
}
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), ""},
/*ADDME: static lease */
{"", NULL, NULL, ""}
};
int read_config(const char *file)
{
FILE *in;
char buffer[READ_CONFIG_BUF_SIZE], orig[READ_CONFIG_BUF_SIZE];
char *token, *line;
int i;
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)) {
if (strchr(buffer, '\n')) *(strchr(buffer, '\n')) = '\0';
strcpy(orig, buffer);
if (strchr(buffer, '#')) *(strchr(buffer, '#')) = '\0';
token = strtok(buffer, " \t");
if(!token)
continue;
line = strtok(NULL, "");
if(!line)
continue;
while(*line == '=' || isspace(*line))
line++;
/* eat trailing whitespace */
for (i = strlen(line); i > 0 && isspace(line[i - 1]); i--);
line[i] = '\0';
if (*line == '\0')
continue;
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, "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++) {
struct dhcpOfferedAddr lease;
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.expires = htonl(lease_time);
memcpy(lease.chaddr, leases[i].chaddr, 16);
lease.yiaddr = leases[i].yiaddr;
fwrite(leases, sizeof(lease), 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(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);
}
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