/* dhcp.c - DHCP client for dynamic network configuration.
*
* Copyright 2012 Madhur Verma <mad.flexi@gmail.com>
* Copyright 2013 Kyungwan Han <asura321@gmail.com>
*
* Not in SUSv4.
USE_DHCP(NEWTOY(dhcp, "V:H:F:x*r:O*A#<0=20T#<0=3t#<0=3s:p:i:SBRCaovqnbf", TOYFLAG_SBIN|TOYFLAG_ROOTONLY))
config DHCP
bool "dhcp"
default n
help
usage: dhcp [-fbnqvoCRB] [-i IFACE] [-r IP] [-s PROG] [-p PIDFILE]
[-H HOSTNAME] [-V VENDOR] [-x OPT:VAL] [-O OPT]
Configure network dynamicaly using DHCP.
-i Interface to use (default eth0)
-p Create pidfile
-s Run PROG at DHCP events (default /usr/share/dhcp/default.script)
-B Request broadcast replies
-t Send up to N discover packets
-T Pause between packets (default 3 seconds)
-A Wait N seconds after failure (default 20)
-f Run in foreground
-b Background if lease is not obtained
-n Exit if lease is not obtained
-q Exit after obtaining lease
-R Release IP on exit
-S Log to syslog too
-a Use arping to validate offered address
-O Request option OPT from server (cumulative)
-o Don't request any options (unless -O is given)
-r Request this IP address
-x OPT:VAL Include option OPT in sent packets (cumulative)
-F Ask server to update DNS mapping for NAME
-H Send NAME as client hostname (default none)
-V VENDOR Vendor identifier (default 'toybox VERSION')
-C Don't send MAC as client identifier
-v Verbose
Signals:
USR1 Renew current lease
USR2 Release current lease
*/
#define FOR_dhcp
#include "toys.h"
// TODO: headers not in posix:
#include <netinet/ip.h>
#include <netinet/udp.h>
#include <netpacket/packet.h>
#include <linux/filter.h> //FIXME: linux specific. fix for other OS ports
#include <linux/if_ether.h>
GLOBALS(
char *iface;
char *pidfile;
char *script;
long retries;
long timeout;
long tryagain;
struct arg_list *req_opt;
char *req_ip;
struct arg_list *pkt_opt;
char *fdn_name;
char *hostname;
char *vendor_cls;
)
#define STATE_INIT 0
#define STATE_REQUESTING 1
#define STATE_BOUND 2
#define STATE_RENEWING 3
#define STATE_REBINDING 4
#define STATE_RENEW_REQUESTED 5
#define STATE_RELEASED 6
#define BOOTP_BROADCAST 0x8000
#define DHCP_MAGIC 0x63825363
#define DHCP_REQUEST 1
#define DHCP_REPLY 2
#define DHCP_HTYPE_ETHERNET 1
#define DHCPC_SERVER_PORT 67
#define DHCPC_CLIENT_PORT 68
#define DHCPDISCOVER 1
#define DHCPOFFER 2
#define DHCPREQUEST 3
#define DHCPACK 5
#define DHCPNAK 6
#define DHCPRELEASE 7
#define DHCP_OPTION_PADDING 0x00
#define DHCP_OPTION_SUBNET_MASK 0x01
#define DHCP_OPTION_ROUTER 0x03
#define DHCP_OPTION_DNS_SERVER 0x06
#define DHCP_OPTION_HOST_NAME 0x0c
#define DHCP_OPTION_BROADCAST 0x1c
#define DHCP_OPTION_REQ_IPADDR 0x32
#define DHCP_OPTION_LEASE_TIME 0x33
#define DHCP_OPTION_OVERLOAD 0x34
#define DHCP_OPTION_MSG_TYPE 0x35
#define DHCP_OPTION_SERVER_ID 0x36
#define DHCP_OPTION_REQ_LIST 0x37
#define DHCP_OPTION_MAX_SIZE 0x39
#define DHCP_OPTION_CLIENTID 0x3D
#define DHCP_OPTION_VENDOR 0x3C
#define DHCP_OPTION_FQDN 0x51
#define DHCP_OPTION_END 0xFF
#define DHCP_NUM8 (1<<8)
#define DHCP_NUM16 (1<<9)
#define DHCP_NUM32 DHCP_NUM16 | DHCP_NUM8
#define DHCP_STRING (1<<10)
#define DHCP_STRLST (1<<11)
#define DHCP_IP (1<<12)
#define DHCP_IPLIST (1<<13)
#define DHCP_IPPLST (1<<14)
#define DHCP_STCRTS (1<<15)
#define LOG_SILENT 0x0
#define LOG_CONSOLE 0x1
#define LOG_SYSTEM 0x2
#define MODE_OFF 0
#define MODE_RAW 1
#define MODE_APP 2
static void (*dbg)(char *format, ...);
static void dummy(char *format, ...){
return;
}
typedef struct dhcpc_result_s {
struct in_addr serverid;
struct in_addr ipaddr;
struct in_addr netmask;
struct in_addr dnsaddr;
struct in_addr default_router;
uint32_t lease_time;
} dhcpc_result_t;
typedef struct __attribute__((packed)) dhcp_msg_s {
uint8_t op;
uint8_t htype;
uint8_t hlen;
uint8_t hops;
uint32_t xid;
uint16_t secs;
uint16_t flags;
uint32_t ciaddr;
uint32_t yiaddr;
uint32_t nsiaddr;
uint32_t ngiaddr;
uint8_t chaddr[16];
uint8_t sname[64];
uint8_t file[128];
uint32_t cookie;
uint8_t options[308];
} dhcp_msg_t;
typedef struct __attribute__((packed)) dhcp_raw_s {
struct iphdr iph;
struct udphdr udph;
dhcp_msg_t dhcp;
} dhcp_raw_t;
typedef struct dhcpc_state_s {
uint8_t macaddr[6];
char *iface;
int ifindex;
int sockfd;
int status;
int mode;
uint32_t mask;
struct in_addr ipaddr;
struct in_addr serverid;
dhcp_msg_t pdhcp;
} dhcpc_state_t;
typedef struct option_val_s {
char *key;
uint16_t code;
void *val;
size_t len;
} option_val_t;
struct fd_pair { int rd; int wr; };
static uint32_t xid;
static dhcpc_state_t *state;
static struct fd_pair sigfd;
uint8_t bmacaddr[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
int set = 1;
uint8_t infomode = LOG_CONSOLE;
uint8_t raw_opt[29];
int raw_optcount = 0;
struct arg_list *x_opt;
in_addr_t server = 0;
static option_val_t *msgopt_list = NULL;
static option_val_t options_list[] = {
{"lease" , DHCP_NUM32 | 0x33, NULL, 0},
{"subnet" , DHCP_IP | 0x01, NULL, 0},
{"broadcast" , DHCP_IP | 0x1c, NULL, 0},
{"router" , DHCP_IP | 0x03, NULL, 0},
{"ipttl" , DHCP_NUM8 | 0x17, NULL, 0},
{"mtu" , DHCP_NUM16 | 0x1a, NULL, 0},
{"hostname" , DHCP_STRING | 0x0c, NULL, 0},
{"domain" , DHCP_STRING | 0x0f, NULL, 0},
{"search" , DHCP_STRLST | 0x77, NULL, 0},
{"nisdomain" , DHCP_STRING | 0x28, NULL, 0},
{"timezone" , DHCP_NUM32 | 0x02, NULL, 0},
{"tftp" , DHCP_STRING | 0x42, NULL, 0},
{"bootfile" , DHCP_STRING | 0x43, NULL, 0},
{"bootsize" , DHCP_NUM16 | 0x0d, NULL, 0},
{"rootpath" , DHCP_STRING | 0x11, NULL, 0},
{"wpad" , DHCP_STRING | 0xfc, NULL, 0},
{"serverid" , DHCP_IP | 0x36, NULL, 0},
{"message" , DHCP_STRING | 0x38, NULL, 0},
{"vlanid" , DHCP_NUM32 | 0x84, NULL, 0},
{"vlanpriority" , DHCP_NUM32 | 0x85, NULL, 0},
{"dns" , DHCP_IPLIST | 0x06, NULL, 0},
{"wins" , DHCP_IPLIST | 0x2c, NULL, 0},
{"nissrv" , DHCP_IPLIST | 0x29, NULL, 0},
{"ntpsrv" , DHCP_IPLIST | 0x2a, NULL, 0},
{"lprsrv" , DHCP_IPLIST | 0x09, NULL, 0},
{"swapsrv" , DHCP_IP | 0x10, NULL, 0},
{"routes" , DHCP_STCRTS | 0x21, NULL, 0},
{"staticroutes" , DHCP_STCRTS | 0x79, NULL, 0},
{"msstaticroutes" , DHCP_STCRTS | 0xf9, NULL, 0},
};
static struct sock_filter filter_instr[] = {
BPF_STMT(BPF_LD|BPF_B|BPF_ABS, 9),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, IPPROTO_UDP, 0, 6),
BPF_STMT(BPF_LD|BPF_H|BPF_ABS, 6),
BPF_JUMP(BPF_JMP|BPF_JSET|BPF_K, 0x1fff, 4, 0),
BPF_STMT(BPF_LDX|BPF_B|BPF_MSH, 0), BPF_STMT(BPF_LD|BPF_H|BPF_IND, 2),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 68, 0, 1),
BPF_STMT(BPF_RET|BPF_K, 0xffffffff), BPF_STMT(BPF_RET|BPF_K, 0),
};
static struct sock_fprog filter_prog = {
.len = ARRAY_LEN(filter_instr),
.filter = (struct sock_filter *) filter_instr,
};
// calculate options size.
static int dhcp_opt_size(uint8_t *optionptr)
{
int i = 0;
for(;optionptr[i] != 0xff; i++) if(optionptr[i] != 0x00) i += optionptr[i + 1] + 2 -1;
return i;
}
// calculates checksum for dhcp messages.
static uint16_t dhcp_checksum(void *addr, int count)
{
int32_t sum = 0;
uint16_t tmp = 0, *source = (uint16_t *)addr;
while (count > 1) {
sum += *source++;
count -= 2;
}
if (count > 0) {
*(uint8_t*)&tmp = *(uint8_t*)source;
sum += tmp;
}
while (sum >> 16) sum = (sum & 0xffff) + (sum >> 16);
return ~sum;
}
// gets information of INTERFACE and updates IFINDEX, MAC and IP
static int get_interface( char *interface, int *ifindex, uint32_t *oip, uint8_t *mac)
{
struct ifreq req;
struct sockaddr_in *ip;
int fd = xsocket(AF_INET, SOCK_RAW, IPPROTO_RAW);
req.ifr_addr.sa_family = AF_INET;
xstrncpy(req.ifr_name, interface, IFNAMSIZ);
req.ifr_name[IFNAMSIZ-1] = '\0';
xioctl(fd, SIOCGIFFLAGS, &req);
if (!(req.ifr_flags & IFF_UP)) return -1;
if (oip) {
xioctl(fd, SIOCGIFADDR, &req);
ip = (struct sockaddr_in*) &req.ifr_addr;
dbg("IP %s\n", inet_ntoa(ip->sin_addr));
*oip = ntohl(ip->sin_addr.s_addr);
}
if (ifindex) {
xioctl(fd, SIOCGIFINDEX, &req);
dbg("Adapter index %d\n", req.ifr_ifindex);
*ifindex = req.ifr_ifindex;
}
if (mac) {
xioctl(fd, SIOCGIFHWADDR, &req);
memcpy(mac, req.ifr_hwaddr.sa_data, 6);
dbg("MAC %02x:%02x:%02x:%02x:%02x:%02x\n", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
}
close(fd);
return 0;
}
/*
*logs messeges to syslog or console
*opening the log is still left with applet.
*FIXME: move to more relevent lib. probably libc.c
*/
static void infomsg(uint8_t infomode, char *s, ...)
{
int used;
char *msg;
va_list p, t;
if (infomode == LOG_SILENT) return;
va_start(p, s);
va_copy(t, p);
used = vsnprintf(NULL, 0, s, t);
used++;
va_end(t);
msg = xmalloc(used);
vsnprintf(msg, used, s, p);
va_end(p);
if (infomode & LOG_SYSTEM) syslog(LOG_INFO, "%s", msg);
if (infomode & LOG_CONSOLE) printf("%s\n", msg);
free(msg);
}
/*
* Writes self PID in file PATH
* FIXME: libc implementation only writes in /var/run
* this is more generic as some implemenation may provide
* arguments to write in specific file. as dhcpd does.
*/
static void write_pid(char *path)
{
int pidfile = open(path, O_CREAT | O_WRONLY | O_TRUNC, 0666);
if (pidfile > 0) {
char pidbuf[12];
sprintf(pidbuf, "%u", (unsigned)getpid());
write(pidfile, pidbuf, strlen(pidbuf));
close(pidfile);
}
}
// String STR to UINT32 conversion strored in VAR
static long strtou32( char *str)
{
char *endptr = NULL;
int base = 10;
errno=0;
if (str[0]=='0' && (str[1]=='x' || str[1]=='X')) {
base = 16;
str+=2;
}
long ret_val = strtol(str, &endptr, base);
if (errno) return -1;
else if (endptr && (*endptr!='\0'||endptr == str)) return -1;
return ret_val;
}
// IP String STR to binary data.
static int striptovar( char *str, void *var)
{
in_addr_t addr;
if(!str) error_exit("NULL address string.");
addr = inet_addr(str);
if(addr == -1) error_exit("Wrong address %s.",str );
*((uint32_t*)(var)) = (uint32_t)addr;
return 0;
}
// String to dhcp option conversion
static int strtoopt( char *str, uint8_t optonly)
{
char *option, *valstr, *grp, *tp;
long optcode = 0, convtmp;
uint16_t flag = 0;
uint32_t mask, nip, router;
int count, size = ARRAY_LEN(options_list);
if (!*str) return 0;
option = strtok((char*)str, ":");
if (!option) return -1;
dbg("-x option : %s ", option);
optcode = strtou32(option);
if (optcode > 0 && optcode < 256) { // raw option
for (count = 0; count < size; count++) {
if ((options_list[count].code & 0X00FF) == optcode) {
flag = (options_list[count].code & 0XFF00);
break;
}
}
if (count == size) error_exit("Obsolete OR Unknown Option : %s", option);
} else { // string option
for (count = 0; count < size; count++) {
if (!strcmp(options_list[count].key, option)) {
flag = (options_list[count].code & 0XFF00);
optcode = (options_list[count].code & 0X00FF);
break;
}
}
if (count == size) error_exit("Obsolete OR Unknown Option : %s", option);
}
if (!flag || !optcode) return -1;
if (optonly) return optcode;
valstr = strtok(NULL, "\n");
if (!valstr) error_exit("option %s has no value defined.\n", option);
dbg(" value : %-20s \n ", valstr);
switch (flag) {
case DHCP_NUM32:
options_list[count].len = sizeof(uint32_t);
options_list[count].val = xmalloc(sizeof(uint32_t));
convtmp = strtou32(valstr);
if (convtmp < 0) error_exit("Invalid/wrong formated number %s", valstr);
convtmp = htonl(convtmp);
memcpy(options_list[count].val, &convtmp, sizeof(uint32_t));
break;
case DHCP_NUM16:
options_list[count].len = sizeof(uint16_t);
options_list[count].val = xmalloc(sizeof(uint16_t));
convtmp = strtou32(valstr);
if (convtmp < 0) error_exit("Invalid/malformed number %s", valstr);
convtmp = htons(convtmp);
memcpy(options_list[count].val, &convtmp, sizeof(uint16_t));
break;
case DHCP_NUM8:
options_list[count].len = sizeof(uint8_t);
options_list[count].val = xmalloc(sizeof(uint8_t));
convtmp = strtou32(valstr);
if (convtmp < 0) error_exit("Invalid/malformed number %s", valstr);
memcpy(options_list[count].val, &convtmp, sizeof(uint8_t));
break;
case DHCP_IP:
options_list[count].len = sizeof(uint32_t);
options_list[count].val = xmalloc(sizeof(uint32_t));
striptovar(valstr, options_list[count].val);
break;
case DHCP_STRING:
options_list[count].len = strlen(valstr);
options_list[count].val = strdup(valstr);
break;
case DHCP_IPLIST:
while(valstr){
options_list[count].val = xrealloc(options_list[count].val, options_list[count].len + sizeof(uint32_t));
striptovar(valstr, ((uint8_t*)options_list[count].val)+options_list[count].len);
options_list[count].len += sizeof(uint32_t);
valstr = strtok(NULL," \t");
}
break;
case DHCP_STRLST:
case DHCP_IPPLST:
break;
case DHCP_STCRTS:
/* Option binary format:
* mask [one byte, 0..32]
* ip [0..4 bytes depending on mask]
* router [4 bytes]
* may be repeated
* staticroutes 10.0.0.0/8 10.127.0.1, 10.11.12.0/24 10.11.12.1
*/
grp = strtok(valstr, ",");;
while(grp){
while(*grp == ' ' || *grp == '\t') grp++;
tp = strchr(grp, '/');
if (!tp) error_exit("malformed static route option");
*tp = '\0';
mask = strtol(++tp, &tp, 10);
if (striptovar(grp, (uint8_t*)&nip) < 0) error_exit("malformed static route option");
while(*tp == ' ' || *tp == '\t' || *tp == '-') tp++;
if (striptovar(tp, (uint8_t*)&router) < 0) error_exit("malformed static route option");
options_list[count].val = xrealloc(options_list[count].val, options_list[count].len + 1 + mask/8 + 4);
memcpy(((uint8_t*)options_list[count].val)+options_list[count].len, &mask, 1);
options_list[count].len += 1;
memcpy(((uint8_t*)options_list[count].val)+options_list[count].len, &nip, mask/8);
options_list[count].len += mask/8;
memcpy(((uint8_t*)options_list[count].val)+options_list[count].len, &router, 4);
options_list[count].len += 4;
tp = NULL;
grp = strtok(NULL, ",");
}
break;
}
return 0;
}
// Creates environment pointers from RES to use in script
static int fill_envp(dhcpc_result_t *res)
{
struct in_addr temp;
int size = ARRAY_LEN(options_list), count, ret = -1;
ret = setenv("interface", state->iface, 1);
if (!res) return ret;
if (res->ipaddr.s_addr) {
temp.s_addr = htonl(res->ipaddr.s_addr);
ret = setenv("ip", inet_ntoa(temp), 1);
if (ret) return ret;
}
if (msgopt_list) {
for (count = 0; count < size; count++) {
if ((msgopt_list[count].len == 0) || (msgopt_list[count].val == NULL)) continue;
ret = setenv(msgopt_list[count].key, (char*)msgopt_list[count].val, 1);
if (ret) return ret;
}
}
return ret;
}
// Executes Script NAME.
static void run_script(dhcpc_result_t *res, char *name)
{
volatile int error = 0;
pid_t pid;
char *argv[3];
struct stat sts;
char *script = (toys.optflags & FLAG_s) ? TT.script
: "/usr/share/dhcp/default.script";
if (stat(script, &sts) == -1 && errno == ENOENT) return;
if (fill_envp(res)) {
dbg("Failed to create environment variables.");
return;
}
dbg("Executing %s %s\n", script, name);
argv[0] = (char*) script;
argv[1] = (char*) name;
argv[2] = NULL;
fflush(NULL);
pid = vfork();
if (pid < 0) {
dbg("Fork failed.\n");
return;
}
if (!pid) {
execvp(argv[0], argv);
error = errno;
_exit(111);
}
if (error) {
waitpid(pid, NULL,0);
errno = error;
perror_msg("script exec failed");
}
dbg("script complete.\n");
}
// returns a randome ID
static uint32_t getxid(void)
{
uint32_t randnum;
int fd = xopen("/dev/urandom", O_RDONLY);
xreadall(fd, &randnum, sizeof(randnum));
xclose(fd);
return randnum;
}
// opens socket in raw mode.
static int mode_raw(void)
{
state->mode = MODE_OFF;
struct sockaddr_ll sock;
if (state->sockfd > 0) close(state->sockfd);
dbg("Opening raw socket on ifindex %d\n", state->ifindex);
state->sockfd = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP));
if (state->sockfd < 0) {
dbg("MODE RAW : socket fail ERROR : %d\n", state->sockfd);
return -1;
}
dbg("Got raw socket fd %d\n", state->sockfd);
memset(&sock, 0, sizeof(sock));
sock.sll_family = AF_PACKET;
sock.sll_protocol = htons(ETH_P_IP);
sock.sll_ifindex = state->ifindex;
if (bind(state->sockfd, (struct sockaddr *) &sock, sizeof(sock))) {
dbg("MODE RAW : bind fail.\n");
close(state->sockfd);
return -1;
}
state->mode = MODE_RAW;
if (setsockopt(state->sockfd, SOL_SOCKET, SO_ATTACH_FILTER, &filter_prog, sizeof(filter_prog)) < 0)
dbg("MODE RAW : filter attach fail.\n");
dbg("MODE RAW : success\n");
return 0;
}
// opens UDP socket
static int mode_app(void)
{
struct sockaddr_in addr;
struct ifreq ifr;
state->mode = MODE_OFF;
if (state->sockfd > 0) close(state->sockfd);
dbg("Opening listen socket on *:%d %s\n", DHCPC_CLIENT_PORT, state->iface);
state->sockfd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
if (state->sockfd < 0) {
dbg("MODE APP : socket fail ERROR: %d\n", state->sockfd);
return -1;
}
setsockopt(state->sockfd, SOL_SOCKET, SO_REUSEADDR, &set, sizeof(set));
if (setsockopt(state->sockfd, SOL_SOCKET, SO_BROADCAST, &set, sizeof(set)) == -1) {
dbg("MODE APP : brodcast failed.\n");
close(state->sockfd);
return -1;
}
xstrncpy(ifr.ifr_name, state->iface, IFNAMSIZ);
ifr.ifr_name[IFNAMSIZ -1] = '\0';
setsockopt(state->sockfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr));
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = htons(DHCPC_CLIENT_PORT);
addr.sin_addr.s_addr = INADDR_ANY ;
if (bind(state->sockfd, (struct sockaddr *) &addr, sizeof(addr))) {
close(state->sockfd);
dbg("MODE APP : bind failed.\n");
return -1;
}
state->mode = MODE_APP;
dbg("MODE APP : success\n");
return 0;
}
static int read_raw(void)
{
dhcp_raw_t packet;
uint16_t check;
int bytes = 0;
memset(&packet, 0, sizeof(packet));
if ((bytes = read(state->sockfd, &packet, sizeof(packet))) < 0) {
dbg("\tPacket read error, ignoring\n");
return bytes;
}
if (bytes < (int) (sizeof(packet.iph) + sizeof(packet.udph))) {
dbg("\tPacket is too short, ignoring\n");
return -2;
}
if (bytes < ntohs(packet.iph.tot_len)) {
dbg("\tOversized packet, ignoring\n");
return -2;
}
// ignore any extra garbage bytes
bytes = ntohs(packet.iph.tot_len);
// make sure its the right packet for us, and that it passes sanity checks
if (packet.iph.protocol != IPPROTO_UDP || packet.iph.version != IPVERSION
|| packet.iph.ihl != (sizeof(packet.iph) >> 2)
|| packet.udph.dest != htons(DHCPC_CLIENT_PORT)
|| ntohs(packet.udph.len) != (uint16_t)(bytes - sizeof(packet.iph))) {
dbg("\tUnrelated/bogus packet, ignoring\n");
return -2;
}
// verify IP checksum
check = packet.iph.check;
packet.iph.check = 0;
if (check != dhcp_checksum(&packet.iph, sizeof(packet.iph))) {
dbg("\tBad IP header checksum, ignoring\n");
return -2;
}
memset(&packet.iph, 0, ((size_t) &((struct iphdr *)0)->protocol));
packet.iph.tot_len = packet.udph.len;
check = packet.udph.check;
packet.udph.check = 0;
if (check && check != dhcp_checksum(&packet, bytes)) {
dbg("\tPacket with bad UDP checksum received, ignoring\n");
return -2;
}
memcpy(&state->pdhcp, &packet.dhcp, bytes - (sizeof(packet.iph) + sizeof(packet.udph)));
if (state->pdhcp.cookie != htonl(DHCP_MAGIC)) {
dbg("\tPacket with bad magic, ignoring\n");
return -2;
}
return bytes - sizeof(packet.iph) - sizeof(packet.udph);
}
static int read_app(void)
{
int ret;
memset(&state->pdhcp, 0, sizeof(dhcp_msg_t));
if ((ret = read(state->sockfd, &state->pdhcp, sizeof(dhcp_msg_t))) < 0) {
dbg("Packet read error, ignoring\n");
return ret; /* returns -1 */
}
if (state->pdhcp.cookie != htonl(DHCP_MAGIC)) {
dbg("Packet with bad magic, ignoring\n");
return -2;
}
return ret;
}
// Sends data through raw socket.
static int send_raw(void)
{
struct sockaddr_ll dest_sll;
dhcp_raw_t packet;
unsigned padding;
int fd, result = -1;
memset(&packet, 0, sizeof(dhcp_raw_t));
memcpy(&packet.dhcp, &state->pdhcp, sizeof(dhcp_msg_t));
if ((fd = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP))) < 0) {
dbg("SEND RAW: socket failed\n");
return result;
}
memset(&dest_sll, 0, sizeof(dest_sll));
dest_sll.sll_family = AF_PACKET;
dest_sll.sll_protocol = htons(ETH_P_IP);
dest_sll.sll_ifindex = state->ifindex;
dest_sll.sll_halen = 6;
memcpy(dest_sll.sll_addr, bmacaddr , 6);
if (bind(fd, (struct sockaddr *) &dest_sll, sizeof(dest_sll)) < 0) {
dbg("SEND RAW: bind failed\n");
close(fd);
return result;
}
padding = 308 - 1 - dhcp_opt_size(state->pdhcp.options);
packet.iph.protocol = IPPROTO_UDP;
packet.iph.saddr = INADDR_ANY;
packet.iph.daddr = INADDR_BROADCAST;
packet.udph.source = htons(DHCPC_CLIENT_PORT);
packet.udph.dest = htons(DHCPC_SERVER_PORT);
packet.udph.len = htons(sizeof(dhcp_raw_t) - sizeof(struct iphdr) - padding);
packet.iph.tot_len = packet.udph.len;
packet.udph.check = dhcp_checksum(&packet, sizeof(dhcp_raw_t) - padding);
packet.iph.tot_len = htons(sizeof(dhcp_raw_t) - padding);
packet.iph.ihl = sizeof(packet.iph) >> 2;
packet.iph.version = IPVERSION;
packet.iph.ttl = IPDEFTTL;
packet.iph.check = dhcp_checksum(&packet.iph, sizeof(packet.iph));
result = sendto(fd, &packet, sizeof(dhcp_raw_t) - padding, 0,
(struct sockaddr *) &dest_sll, sizeof(dest_sll));
close(fd);
if (result < 0) dbg("SEND RAW: PACKET send error\n");
return result;
}
// Sends data through UDP socket.
static int send_app(void)
{
struct sockaddr_in cli;
int fd, ret = -1;
if ((fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
dbg("SEND APP: sock failed.\n");
return ret;
}
setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &set, sizeof(set));
memset(&cli, 0, sizeof(cli));
cli.sin_family = AF_INET;
cli.sin_port = htons(DHCPC_CLIENT_PORT);
cli.sin_addr.s_addr = state->pdhcp.ciaddr;
if (bind(fd, (struct sockaddr *)&cli, sizeof(cli)) == -1) {
dbg("SEND APP: bind failed.\n");
goto error_fd;
}
memset(&cli, 0, sizeof(cli));
cli.sin_family = AF_INET;
cli.sin_port = htons(DHCPC_SERVER_PORT);
cli.sin_addr.s_addr = state->serverid.s_addr;
if (connect(fd, (struct sockaddr *)&cli, sizeof(cli)) == -1) {
dbg("SEND APP: connect failed.\n");
goto error_fd;
}
int padding = 308 - 1 - dhcp_opt_size(state->pdhcp.options);
if((ret = write(fd, &state->pdhcp, sizeof(dhcp_msg_t) - padding)) < 0) {
dbg("SEND APP: write failed error %d\n", ret);
goto error_fd;
}
dbg("SEND APP: write success wrote %d\n", ret);
error_fd:
close(fd);
return ret;
}
// Generic signal handler real handling is done in main funcrion.
static void signal_handler(int sig)
{
unsigned char ch = sig;
if (write(sigfd.wr, &ch, 1) != 1) dbg("can't send signal\n");
}
// signal setup for SIGUSR1 SIGUSR2 SIGTERM
static int setup_signal()
{
if (pipe((int *)&sigfd) < 0) {
dbg("signal pipe failed\n");
return -1;
}
fcntl(sigfd.wr , F_SETFD, FD_CLOEXEC);
fcntl(sigfd.rd , F_SETFD, FD_CLOEXEC);
int flags = fcntl(sigfd.wr, F_GETFL);
fcntl(sigfd.wr, F_SETFL, flags | O_NONBLOCK);
signal(SIGUSR1, signal_handler);
signal(SIGUSR2, signal_handler);
signal(SIGTERM, signal_handler);
return 0;
}
// adds client id to dhcp packet
static uint8_t *dhcpc_addclientid(uint8_t *optptr)
{
*optptr++ = DHCP_OPTION_CLIENTID;
*optptr++ = 7;
*optptr++ = 1;
memcpy(optptr, &state->macaddr, 6);
return optptr + 6;
}
// adds messege type to dhcp packet
static uint8_t *dhcpc_addmsgtype(uint8_t *optptr, uint8_t type)
{
*optptr++ = DHCP_OPTION_MSG_TYPE;
*optptr++ = 1;
*optptr++ = type;
return optptr;
}
// adds max size to dhcp packet
static uint8_t *dhcpc_addmaxsize(uint8_t *optptr, uint16_t size)
{
*optptr++ = DHCP_OPTION_MAX_SIZE;
*optptr++ = 2;
memcpy(optptr, &size, 2);
return optptr + 2;
}
static uint8_t *dhcpc_addstropt(uint8_t *optptr, uint8_t opcode, char* str, int len)
{
*optptr++ = opcode;
*optptr++ = len;
memcpy(optptr, str, len);
return optptr + len;
}
// adds server id to dhcp packet.
static uint8_t *dhcpc_addserverid(struct in_addr *serverid, uint8_t *optptr)
{
*optptr++ = DHCP_OPTION_SERVER_ID;
*optptr++ = 4;
memcpy(optptr, &serverid->s_addr, 4);
return optptr + 4;
}
// adds requested ip address to dhcp packet.
static uint8_t *dhcpc_addreqipaddr(struct in_addr *ipaddr, uint8_t *optptr)
{
*optptr++ = DHCP_OPTION_REQ_IPADDR;
*optptr++ = 4;
memcpy(optptr, &ipaddr->s_addr, 4);
return optptr + 4;
}
// adds hostname to dhcp packet.
static uint8_t *dhcpc_addfdnname(uint8_t *optptr, char *hname)
{
int size = strlen(hname);
*optptr++ = DHCP_OPTION_FQDN;
*optptr++ = size + 3;
*optptr++ = 0x1; //flags
optptr += 2; // two blank bytes
strcpy((char*)optptr, hname); // name
return optptr + size;
}
// adds request options using -o,-O flag to dhcp packet
static uint8_t *dhcpc_addreqoptions(uint8_t *optptr)
{
uint8_t *len;
*optptr++ = DHCP_OPTION_REQ_LIST;
len = optptr;
*len = 0;
optptr++;
if (!(toys.optflags & FLAG_o)) {
*len = 4;
*optptr++ = DHCP_OPTION_SUBNET_MASK;
*optptr++ = DHCP_OPTION_ROUTER;
*optptr++ = DHCP_OPTION_DNS_SERVER;
*optptr++ = DHCP_OPTION_BROADCAST;
}
if (toys.optflags & FLAG_O) {
memcpy(optptr++, raw_opt, raw_optcount);
*len += raw_optcount;
}
return optptr;
}
static uint8_t *dhcpc_addend(uint8_t *optptr)
{
*optptr++ = DHCP_OPTION_END;
return optptr;
}
// Sets values of -x options in dhcp discover and request packet.
static uint8_t* set_xopt(uint8_t *optptr)
{
int count;
int size = ARRAY_LEN(options_list);
for (count = 0; count < size; count++) {
if ((options_list[count].len == 0) || (options_list[count].val == NULL)) continue;
*optptr++ = (uint8_t) (options_list[count].code & 0x00FF);
*optptr++ = (uint8_t) options_list[count].len;
memcpy(optptr, options_list[count].val, options_list[count].len);
optptr += options_list[count].len;
}
return optptr;
}
static uint32_t get_option_serverid (uint8_t *opt, dhcpc_result_t *presult)
{
uint32_t var = 0;
while (*opt != DHCP_OPTION_SERVER_ID) {
if (*opt == DHCP_OPTION_END) return var;
opt += opt[1] + 2;
}
memcpy(&var, opt+2, sizeof(uint32_t));
state->serverid.s_addr = var;
presult->serverid.s_addr = state->serverid.s_addr;
presult->serverid.s_addr = ntohl(presult->serverid.s_addr);
return var;
}
static uint8_t get_option_msgtype(uint8_t *opt)
{
uint32_t var = 0;
while (*opt != DHCP_OPTION_MSG_TYPE) {
if (*opt == DHCP_OPTION_END) return var;
opt += opt[1] + 2;
}
memcpy(&var, opt+2, sizeof(uint8_t));
return var;
}
static uint8_t get_option_lease(uint8_t *opt, dhcpc_result_t *presult)
{
uint32_t var = 0;
while (*opt != DHCP_OPTION_LEASE_TIME) {
if (*opt == DHCP_OPTION_END) return var;
opt += opt[1] + 2;
}
memcpy(&var, opt+2, sizeof(uint32_t));
var = htonl(var);
presult->lease_time = var;
return var;
}
// sends dhcp msg of MSGTYPE
static int dhcpc_sendmsg(int msgtype)
{
uint8_t *pend;
struct in_addr rqsd;
char *vendor;
// Create the common message header settings
memset(&state->pdhcp, 0, sizeof(dhcp_msg_t));
state->pdhcp.op = DHCP_REQUEST;
state->pdhcp.htype = DHCP_HTYPE_ETHERNET;
state->pdhcp.hlen = 6;
state->pdhcp.xid = xid;
memcpy(state->pdhcp.chaddr, state->macaddr, 6);
memset(&state->pdhcp.chaddr[6], 0, 10);
state->pdhcp.cookie = htonl(DHCP_MAGIC);;
// Add the common header options
pend = state->pdhcp.options;
pend = dhcpc_addmsgtype(pend, msgtype);
if (!(toys.optflags & FLAG_C)) pend = dhcpc_addclientid(pend);
// Handle the message specific settings
switch (msgtype) {
case DHCPDISCOVER: // Broadcast DISCOVER message to all servers
state->pdhcp.flags = htons(BOOTP_BROADCAST); // Broadcast bit.
if (toys.optflags & FLAG_r) {
inet_aton(TT.req_ip, &rqsd);
pend = dhcpc_addreqipaddr(&rqsd, pend);
}
pend = dhcpc_addmaxsize(pend, htons(sizeof(dhcp_raw_t)));
vendor = (toys.optflags & FLAG_V) ? TT.vendor_cls : "toybox\0";
pend = dhcpc_addstropt(pend, DHCP_OPTION_VENDOR, vendor, strlen(vendor));
if (toys.optflags & FLAG_H) pend = dhcpc_addstropt(pend, DHCP_OPTION_HOST_NAME, TT.hostname, strlen(TT.hostname));
if (toys.optflags & FLAG_F) pend = dhcpc_addfdnname(pend, TT.fdn_name);
if (!(toys.optflags & FLAG_o) || (toys.optflags & FLAG_O))
pend = dhcpc_addreqoptions(pend);
if (toys.optflags & FLAG_x) pend = set_xopt(pend);
break;
case DHCPREQUEST: // Send REQUEST message to the server that sent the *first* OFFER
state->pdhcp.flags = htons(BOOTP_BROADCAST); // Broadcast bit.
if (state->status == STATE_RENEWING) memcpy(&state->pdhcp.ciaddr, &state->ipaddr.s_addr, 4);
pend = dhcpc_addmaxsize(pend, htons(sizeof(dhcp_raw_t)));
rqsd.s_addr = htonl(server);
pend = dhcpc_addserverid(&rqsd, pend);
pend = dhcpc_addreqipaddr(&state->ipaddr, pend);
vendor = (toys.optflags & FLAG_V) ? TT.vendor_cls : "toybox\0";
pend = dhcpc_addstropt(pend, DHCP_OPTION_VENDOR, vendor, strlen(vendor));
if (toys.optflags & FLAG_H) pend = dhcpc_addstropt(pend, DHCP_OPTION_HOST_NAME, TT.hostname, strlen(TT.hostname));
if (toys.optflags & FLAG_F) pend = dhcpc_addfdnname(pend, TT.fdn_name);
if (!(toys.optflags & FLAG_o) || (toys.optflags & FLAG_O))
pend = dhcpc_addreqoptions(pend);
if (toys.optflags & FLAG_x) pend = set_xopt(pend);
break;
case DHCPRELEASE: // Send RELEASE message to the server.
memcpy(&state->pdhcp.ciaddr, &state->ipaddr.s_addr, 4);
rqsd.s_addr = htonl(server);
pend = dhcpc_addserverid(&rqsd, pend);
break;
default:
return -1;
}
pend = dhcpc_addend(pend);
if (state->mode == MODE_APP) return send_app();
return send_raw();
}
/*
* parses options from received dhcp packet at OPTPTR and
* stores result in PRESULT or MSGOPT_LIST
*/
static uint8_t dhcpc_parseoptions(dhcpc_result_t *presult, uint8_t *optptr)
{
uint8_t type = 0, *options, overloaded = 0;;
uint16_t flag = 0;
uint32_t convtmp = 0;
char *dest, *pfx;
struct in_addr addr;
int count, optlen, size = ARRAY_LEN(options_list);
if (toys.optflags & FLAG_x) {
if(msgopt_list){
for (count = 0; count < size; count++){
if(msgopt_list[count].val) free(msgopt_list[count].val);
msgopt_list[count].val = NULL;
msgopt_list[count].len = 0;
}
} else {
msgopt_list = xmalloc(sizeof(options_list));
memcpy(msgopt_list, options_list, sizeof(options_list));
for (count = 0; count < size; count++) {
msgopt_list[count].len = 0;
msgopt_list[count].val = NULL;
}
}
} else {
msgopt_list = options_list;
for (count = 0; count < size; count++) {
msgopt_list[count].len = 0;
if(msgopt_list[count].val) free(msgopt_list[count].val);
msgopt_list[count].val = NULL;
}
}
while (*optptr != DHCP_OPTION_END) {
if (*optptr == DHCP_OPTION_PADDING) {
optptr++;
continue;
}
if (*optptr == DHCP_OPTION_OVERLOAD) {
overloaded = optptr[2];
optptr += optptr[1] + 2;
continue;
}
for (count = 0, flag = 0; count < size; count++) {
if ((msgopt_list[count].code & 0X00FF) == *optptr) {
flag = (msgopt_list[count].code & 0XFF00);
break;
}
}
switch (flag) {
case DHCP_NUM32:
memcpy(&convtmp, &optptr[2], sizeof(uint32_t));
convtmp = htonl(convtmp);
sprintf(toybuf, "%u", convtmp);
msgopt_list[count].val = strdup(toybuf);
msgopt_list[count].len = strlen(toybuf);
break;
case DHCP_NUM16:
memcpy(&convtmp, &optptr[2], sizeof(uint16_t));
convtmp = htons(convtmp);
sprintf(toybuf, "%u", convtmp);
msgopt_list[count].val = strdup(toybuf);
msgopt_list[count].len = strlen(toybuf);
break;
case DHCP_NUM8:
memcpy(&convtmp, &optptr[2], sizeof(uint8_t));
sprintf(toybuf, "%u", convtmp);
msgopt_list[count].val = strdup(toybuf);
msgopt_list[count].len = strlen(toybuf);
break;
case DHCP_IP:
memcpy(&convtmp, &optptr[2], sizeof(uint32_t));
addr.s_addr = convtmp;
sprintf(toybuf, "%s", inet_ntoa(addr));
msgopt_list[count].val = strdup(toybuf);
msgopt_list[count].len = strlen(toybuf);
break;
case DHCP_STRING:
sprintf(toybuf, "%.*s", optptr[1], &optptr[2]);
msgopt_list[count].val = strdup(toybuf);
msgopt_list[count].len = strlen(toybuf);
break;
case DHCP_IPLIST:
optlen = optptr[1];
dest = toybuf;
while (optlen) {
memcpy(&convtmp, &optptr[2], sizeof(uint32_t));
addr.s_addr = convtmp;
dest += sprintf(dest, "%s ", inet_ntoa(addr));
optlen -= 4;
}
*(dest - 1) = '\0';
msgopt_list[count].val = strdup(toybuf);
msgopt_list[count].len = strlen(toybuf);
break;
case DHCP_STRLST: //FIXME: do smthing.
case DHCP_IPPLST:
break;
case DHCP_STCRTS:
pfx = "";
dest = toybuf;
options = &optptr[2];
optlen = optptr[1];
while (optlen >= 1 + 4) {
uint32_t nip = 0;
int bytes;
uint8_t *p_tmp;
unsigned mask = *options;
if (mask > 32) break;
optlen--;
p_tmp = (void*) &nip;
bytes = (mask + 7) / 8;
while (--bytes >= 0) {
*p_tmp++ = *options++;
optlen--;
}
if (optlen < 4) break;
dest += sprintf(dest, "%s%u.%u.%u.%u", pfx, ((uint8_t*) &nip)[0],
((uint8_t*) &nip)[1], ((uint8_t*) &nip)[2], ((uint8_t*) &nip)[3]);
pfx = " ";
dest += sprintf(dest, "/%u ", mask);
dest += sprintf(dest, "%u.%u.%u.%u", options[0], options[1], options[2], options[3]);
options += 4;
optlen -= 4;
}
msgopt_list[count].val = strdup(toybuf);
msgopt_list[count].len = strlen(toybuf);
break;
default: break;
}
optptr += optptr[1] + 2;
}
if ((overloaded == 1) || (overloaded == 3)) dhcpc_parseoptions(presult, optptr);
if ((overloaded == 2) || (overloaded == 3)) dhcpc_parseoptions(presult, optptr);
return type;
}
// parses recvd messege to check that it was for us.
static uint8_t dhcpc_parsemsg(dhcpc_result_t *presult)
{
if (state->pdhcp.op == DHCP_REPLY
&& !memcmp(state->pdhcp.chaddr, state->macaddr, 6)
&& !memcmp(&state->pdhcp.xid, &xid, sizeof(xid))) {
memcpy(&presult->ipaddr.s_addr, &state->pdhcp.yiaddr, 4);
presult->ipaddr.s_addr = ntohl(presult->ipaddr.s_addr);
return get_option_msgtype(state->pdhcp.options);
}
return 0;
}
// Sends a IP renew request.
static void renew(void)
{
infomsg(infomode, "Performing a DHCP renew");
switch (state->status) {
case STATE_INIT:
break;
case STATE_BOUND:
mode_raw();
case STATE_RENEWING: // FALLTHROUGH
case STATE_REBINDING: // FALLTHROUGH
state->status = STATE_RENEW_REQUESTED;
break;
case STATE_RENEW_REQUESTED:
run_script(NULL, "deconfig");
case STATE_REQUESTING: // FALLTHROUGH
case STATE_RELEASED: // FALLTHROUGH
mode_raw();
state->status = STATE_INIT;
break;
default: break;
}
}
// Sends a IP release request.
static void release(void)
{
char buffer[sizeof("255.255.255.255\0")];
struct in_addr temp_addr;
mode_app();
// send release packet
if (state->status == STATE_BOUND || state->status == STATE_RENEWING || state->status == STATE_REBINDING) {
temp_addr.s_addr = htonl(server);
xstrncpy(buffer, inet_ntoa(temp_addr), sizeof(buffer));
temp_addr.s_addr = state->ipaddr.s_addr;
infomsg( infomode, "Unicasting a release of %s to %s", inet_ntoa(temp_addr), buffer);
dhcpc_sendmsg(DHCPRELEASE);
run_script(NULL, "deconfig");
}
infomsg(infomode, "Entering released state");
close(state->sockfd);
state->sockfd = -1;
state->mode = MODE_OFF;
state->status = STATE_RELEASED;
}
static void free_option_stores(void)
{
int count, size = ARRAY_LEN(options_list);
for (count = 0; count < size; count++)
if (options_list[count].val) free(options_list[count].val);
if (toys.optflags & FLAG_x) {
for (count = 0; count < size; count++)
if (msgopt_list[count].val) free(msgopt_list[count].val);
free(msgopt_list);
}
}
void dhcp_main(void)
{
struct timeval tv;
int retval, bufflen = 0;
dhcpc_result_t result;
uint8_t packets = 0, retries = 0;
uint32_t timeout = 0, waited = 0;
fd_set rfds;
xid = 0;
setlinebuf(stdout);
dbg = dummy;
if (toys.optflags & FLAG_v) dbg = xprintf;
if (toys.optflags & FLAG_p) write_pid(TT.pidfile);
retries = TT.retries;
if (toys.optflags & FLAG_S) {
openlog("UDHCPC :", LOG_PID, LOG_DAEMON);
infomode |= LOG_SYSTEM;
}
infomsg(infomode, "dhcp started");
if (toys.optflags & FLAG_O) {
while (TT.req_opt) {
raw_opt[raw_optcount] = (uint8_t) strtoopt(TT.req_opt->arg, 1);
raw_optcount++;
TT.req_opt = TT.req_opt->next;
}
}
if (toys.optflags & FLAG_x) {
while (TT.pkt_opt) {
(void) strtoopt(TT.pkt_opt->arg, 0);
TT.pkt_opt = TT.pkt_opt->next;
}
}
memset(&result, 0, sizeof(dhcpc_result_t));
state = (dhcpc_state_t*) xmalloc(sizeof(dhcpc_state_t));
memset(state, 0, sizeof(dhcpc_state_t));
state->iface = (toys.optflags & FLAG_i) ? TT.iface : "eth0";
if (get_interface(state->iface, &state->ifindex, NULL, state->macaddr))
perror_exit("Failed to get interface %s", state->iface);
run_script(NULL, "deconfig");
setup_signal();
state->status = STATE_INIT;
mode_raw();
fcntl(state->sockfd, F_SETFD, FD_CLOEXEC);
for (;;) {
FD_ZERO(&rfds);
if (state->sockfd >= 0) FD_SET(state->sockfd, &rfds);
FD_SET(sigfd.rd, &rfds);
tv.tv_sec = timeout - waited;
tv.tv_usec = 0;
retval = 0;
int maxfd = (sigfd.rd > state->sockfd)? sigfd.rd : state->sockfd;
dbg("select wait ....\n");
uint32_t timestmp = time(NULL);
if((retval = select(maxfd + 1, &rfds, NULL, NULL, &tv)) < 0) {
if (errno == EINTR) {
waited += (unsigned) time(NULL) - timestmp;
continue;
}
perror_exit("Error in select");
}
if (!retval) { // Timed out
if (get_interface(state->iface, &state->ifindex, NULL, state->macaddr))
error_exit("Interface lost %s\n", state->iface);
switch (state->status) {
case STATE_INIT:
if (packets < retries) {
if (!packets) xid = getxid();
run_script(NULL, "deconfig");
infomsg(infomode, "Sending discover...");
dhcpc_sendmsg(DHCPDISCOVER);
server = 0;
timeout = TT.timeout;
waited = 0;
packets++;
continue;
}
lease_fail:
run_script(NULL,"leasefail");
if (toys.optflags & FLAG_n) {
infomsg(infomode, "Lease failed. Exiting");
goto ret_with_sockfd;
}
if (toys.optflags & FLAG_b) {
infomsg(infomode, "Lease failed. Going Daemon mode");
daemon(0, 0);
if (toys.optflags & FLAG_p) write_pid(TT.pidfile);
toys.optflags &= ~FLAG_b;
toys.optflags |= FLAG_f;
}
timeout = TT.tryagain;
waited = 0;
packets = 0;
continue;
case STATE_REQUESTING:
if (packets < retries) {
memcpy(&state->ipaddr.s_addr,&state->pdhcp.yiaddr, 4);
dhcpc_sendmsg(DHCPREQUEST);
infomsg(infomode, "Sending select for %d.%d.%d.%d...",
(result.ipaddr.s_addr >> 24) & 0xff, (result.ipaddr.s_addr >> 16) & 0xff, (result.ipaddr.s_addr >> 8) & 0xff, (result.ipaddr.s_addr) & 0xff);
timeout = TT.timeout;
waited = 0;
packets++;
continue;
}
mode_raw();
state->status = STATE_INIT;
goto lease_fail;
case STATE_BOUND:
state->status = STATE_RENEWING;
dbg("Entering renew state\n");
// FALLTHROUGH
case STATE_RENEW_REQUESTED: // FALLTHROUGH
case STATE_RENEWING:
renew_requested:
if (timeout > 60) {
dhcpc_sendmsg(DHCPREQUEST);
timeout >>= 1;
waited = 0;
continue;
}
dbg("Entering rebinding state\n");
state->status = STATE_REBINDING;
// FALLTHROUGH
case STATE_REBINDING:
mode_raw();
if (timeout > 0) {
dhcpc_sendmsg(DHCPREQUEST);
timeout >>= 1;
waited = 0;
continue;
}
infomsg(infomode, "Lease lost, entering INIT state");
run_script(NULL, "deconfig");
state->status = STATE_INIT;
timeout = 0;
waited = 0;
packets = 0;
continue;
default: break;
}
timeout = INT_MAX;
waited = 0;
continue;
}
if (FD_ISSET(sigfd.rd, &rfds)) { // Some Activity on RDFDs : is signal
unsigned char sig;
if (read(sigfd.rd, &sig, 1) != 1) {
dbg("signal read failed.\n");
continue;
}
switch (sig) {
case SIGUSR1:
infomsg(infomode, "Received SIGUSR1");
renew();
packets = 0;
waited = 0;
if (state->status == STATE_RENEW_REQUESTED) goto renew_requested;
if (state->status == STATE_INIT) timeout = 0;
continue;
case SIGUSR2:
infomsg(infomode, "Received SIGUSR2");
release();
timeout = INT_MAX;
waited = 0;
packets = 0;
continue;
case SIGTERM:
infomsg(infomode, "Received SIGTERM");
if (toys.optflags & FLAG_R) release();
goto ret_with_sockfd;
default: break;
}
}
if (FD_ISSET(state->sockfd, &rfds)) { // Some Activity on RDFDs : is socket
dbg("main sock read\n");
uint8_t msgType;
if (state->mode == MODE_RAW) bufflen = read_raw();
if (state->mode == MODE_APP) bufflen = read_app();
if (bufflen < 0) {
if (state->mode == MODE_RAW) mode_raw();
if (state->mode == MODE_APP) mode_app();
continue;
}
waited += time(NULL) - timestmp;
memset(&result, 0, sizeof(dhcpc_result_t));
msgType = dhcpc_parsemsg(&result);
if (msgType != DHCPNAK && result.ipaddr.s_addr == 0 ) continue; // no ip for me ignore
if (!msgType || !get_option_serverid(state->pdhcp.options, &result)) continue; //no server id ignore
if (msgType == DHCPOFFER && server == 0) server = result.serverid.s_addr; // select the server
if (result.serverid.s_addr != server) continue; // not from the server we requested ignore
dhcpc_parseoptions(&result, state->pdhcp.options);
get_option_lease(state->pdhcp.options, &result);
switch (state->status) {
case STATE_INIT:
if (msgType == DHCPOFFER) {
state->status = STATE_REQUESTING;
mode_raw();
timeout = 0;
waited = 0;
packets = 0;
}
continue;
case STATE_REQUESTING: // FALLTHROUGH
case STATE_RENEWING: // FALLTHROUGH
case STATE_RENEW_REQUESTED: // FALLTHROUGH
case STATE_REBINDING:
if (msgType == DHCPACK) {
timeout = result.lease_time / 2;
run_script(&result, state->status == STATE_REQUESTING ? "bound" : "renew");
state->status = STATE_BOUND;
infomsg(infomode, "Lease of %d.%d.%d.%d obtained, lease time %d from server %d.%d.%d.%d",
(result.ipaddr.s_addr >> 24) & 0xff, (result.ipaddr.s_addr >> 16) & 0xff, (result.ipaddr.s_addr >> 8) & 0xff, (result.ipaddr.s_addr) & 0xff,
result.lease_time,
(result.serverid.s_addr >> 24) & 0xff, (result.serverid.s_addr >> 16) & 0xff, (result.serverid.s_addr >> 8) & 0xff, (result.serverid.s_addr) & 0xff);
if (toys.optflags & FLAG_q) {
if (toys.optflags & FLAG_R) release();
goto ret_with_sockfd;
}
toys.optflags &= ~FLAG_n;
if (!(toys.optflags & FLAG_f)) {
daemon(0, 0);
toys.optflags |= FLAG_f;
if (toys.optflags & FLAG_p) write_pid(TT.pidfile);
}
waited = 0;
continue;
} else if (msgType == DHCPNAK) {
dbg("NACK received.\n");
run_script(&result, "nak");
if (state->status != STATE_REQUESTING) run_script(NULL, "deconfig");
mode_raw();
sleep(3);
state->status = STATE_INIT;
state->ipaddr.s_addr = 0;
server = 0;
timeout = 0;
packets = 0;
waited = 0;
}
continue;
default: break;
}
}
}
ret_with_sockfd:
if (CFG_TOYBOX_FREE) {
free_option_stores();
if (state->sockfd > 0) close(state->sockfd);
free(state);
}
}