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nmrpflash/nmrp.c
David Keck 50171ba46b
fix minor typo
2020-12-13 22:54:56 -05:00

756 lines
17 KiB
C
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/**
* nmrpflash - Netgear Unbrick Utility
* Copyright (C) 2016 Joseph Lehner <joseph.c.lehner@gmail.com>
*
* nmrpflash is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* nmrpflash is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with nmrpflash. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <time.h>
#include "nmrpd.h"
#define NMRP_HDR_LEN 6
#define NMRP_OPT_HDR_LEN 4
#define NMRP_MIN_PKT_LEN (sizeof(struct eth_hdr) + NMRP_HDR_LEN)
#define ETH_P_NMRP 0x0912
#ifndef PACKED
#define PACKED __attribute__((__packed__))
#endif
#ifdef NMRPFLASH_WINDOWS
#define setenv(name, value, overwrite) SetEnvironmentVariable(name, value)
#endif
enum nmrp_code {
NMRP_C_NONE = 0,
NMRP_C_ADVERTISE = 1,
NMRP_C_CONF_REQ = 2,
NMRP_C_CONF_ACK = 3,
NMRP_C_CLOSE_REQ = 4,
NMRP_C_CLOSE_ACK = 5,
NMRP_C_KEEP_ALIVE_REQ = 6,
NMRP_C_KEEP_ALIVE_ACK = 7,
NMRP_C_TFTP_UL_REQ = 16
};
enum nmrp_opt_type {
NMRP_O_MAGIC_NO = 0x0001,
NMRP_O_DEV_IP = 0x0002,
NMRP_O_DEV_REGION = 0x0004,
NMRP_O_FW_UP = 0x0101,
NMRP_O_ST_UP = 0x0102,
NMRP_O_FILE_NAME = 0x0181
};
struct nmrp_opt {
uint16_t type;
uint16_t len;
char val[1];
} PACKED;
struct nmrp_msg {
uint16_t reserved;
uint8_t code;
uint8_t id;
uint16_t len;
char opts[44];
} PACKED;
struct nmrp_pkt {
struct eth_hdr eh;
struct nmrp_msg msg;
} PACKED;
static const char *msg_code_str(uint16_t code)
{
#define MSG_CODE(x) case NMRP_C_ ## x: return #x
static char buf[16];
switch (code) {
MSG_CODE(ADVERTISE);
MSG_CODE(CONF_REQ);
MSG_CODE(CONF_ACK);
MSG_CODE(CLOSE_REQ);
MSG_CODE(CLOSE_ACK);
MSG_CODE(KEEP_ALIVE_REQ);
MSG_CODE(KEEP_ALIVE_ACK);
MSG_CODE(TFTP_UL_REQ);
default:
snprintf(buf, sizeof(buf), "%04x", ntohs(code));
return buf;
}
#undef MSG_CODE
}
static uint16_t to_region_code(const char *region)
{
#define REGION_CODE(r, c) if (!strcasecmp(region, r)) return htons(c)
REGION_CODE("NA", 0x0001);
REGION_CODE("WW", 0x0002);
REGION_CODE("GR", 0x0003);
REGION_CODE("PR", 0x0004);
REGION_CODE("RU", 0x0005);
REGION_CODE("BZ", 0x0006);
REGION_CODE("IN", 0x0007);
REGION_CODE("KO", 0x0008);
REGION_CODE("JP", 0x0009);
#undef REGION_CODE
return 0;
}
static void msg_dump(struct nmrp_msg *msg)
{
int rem;
fprintf(stderr, "res=0x%04x, code=0x%02x, id=0x%02x, len=%u",
ntohs(msg->reserved), msg->code, msg->id, ntohs(msg->len));
rem = ntohs(msg->len) - NMRP_HDR_LEN;
fprintf(stderr, "%s\n", rem ? "" : " (no opts)");
}
static void *msg_opt(struct nmrp_msg *msg, uint16_t type, uint16_t* len)
{
struct nmrp_opt* opt = (struct nmrp_opt*)msg->opts;
size_t rem = ntohs(msg->len) - NMRP_HDR_LEN;
uint16_t olen;
do {
olen = ntohs(opt->len);
if (olen < NMRP_OPT_HDR_LEN || olen > rem) {
break;
}
if (ntohs(opt->type) == type) {
if (len) {
*len = olen;
}
return opt->val;
}
opt = (struct nmrp_opt*)(((char *)opt) + olen);
rem -= olen;
} while (rem);
return NULL;
}
static char *msg_filename(struct nmrp_msg *msg)
{
static char buf[256];
uint16_t len;
char *p = msg_opt(msg, NMRP_O_FILE_NAME, &len);
if (p) {
len = MIN(sizeof(buf) - 1, len);
memcpy(buf, p, len);
buf[len] = '\0';
return buf;
}
return NULL;
}
static inline void msg_init(struct nmrp_msg *msg, uint16_t code)
{
memset(msg, 0, sizeof(*msg));
msg->len = htons(NMRP_HDR_LEN);
msg->code = code;
}
static char *msg_mkopt(struct nmrp_msg *msg, char *p, uint16_t type, const void *val, size_t len)
{
struct nmrp_opt* opt = (struct nmrp_opt*)p;
len &= 0xffff;
msg->len = ntohs(msg->len);
if ((msg->len + len > sizeof(*msg))) {
fprintf(stderr, "Error: invalid option - this is a bug\n");
exit(1);
}
opt->type = htons(type);
opt->len = NMRP_OPT_HDR_LEN + len;
if (val) {
memcpy(opt->val, val, len);
}
msg->len += opt->len;
p += opt->len;
msg->len = htons(msg->len);
opt->len = htons(opt->len);
return p;
}
static void msg_mkadvertise(struct nmrp_msg *msg, const char *magic)
{
msg_init(msg, NMRP_C_ADVERTISE);
msg_mkopt(msg, msg->opts, NMRP_O_MAGIC_NO, magic, strlen(magic));
}
static void msg_mkconfack(struct nmrp_msg *msg, uint32_t ipaddr, uint32_t ipmask, uint16_t region)
{
char *p;
uint32_t ip[2] = { ipaddr, ipmask };
msg_init(msg, NMRP_C_CONF_ACK);
p = msg_mkopt(msg, msg->opts, NMRP_O_DEV_IP, &ip, 8);
p = msg_mkopt(msg, p, NMRP_O_FW_UP, NULL, 0);
#ifdef NMRPFLASH_SET_REGION
if (region) {
p = msg_mkopt(msg, p, NMRP_O_DEV_REGION, &region, 2);
}
#endif
}
#ifdef NMRPFLASH_FUZZ
#define NMRP_ADVERTISE_TIMEOUT 0
#define ethsock_create(a, b) ((struct ethsock*)1)
#define ethsock_get_hwaddr(a) ethsock_get_hwaddr_fake(a)
#define ethsock_recv(sock, buf, len) read(STDIN_FILENO, buf, len)
#define ethsock_send(a, b, c) (0)
#define ethsock_set_timeout(a, b) (0)
#define ethsock_arp_add(a, b, c, d) (0)
#define ethsock_arp_del(a, b) (0)
#define ethsock_ip_add(a, b, c, d) (0)
#define ethsock_ip_del(a, b) (0)
#define ethsock_close(a) (0)
#define ethsock_for_each_ip(a, b, c) (1)
#define tftp_put(a) (0)
static uint8_t *ethsock_get_hwaddr_fake(struct ethsock* sock)
{
static uint8_t hwaddr[6] = { 0xfa, 0xfa, 0xfa, 0xfa, 0xfa, 0xfa };
return hwaddr;
}
#else
#define NMRP_ADVERTISE_TIMEOUT 60
#endif
static int pkt_send(struct ethsock *sock, struct nmrp_pkt *pkt)
{
return ethsock_send(sock, pkt, sizeof(*pkt));
}
static int pkt_recv(struct ethsock *sock, struct nmrp_pkt *pkt)
{
ssize_t bytes, mlen;
memset(pkt, 0, sizeof(*pkt));
bytes = ethsock_recv(sock, pkt, sizeof(*pkt));
if (bytes < 0) {
return 1;
} else if (!bytes) {
return 2;
}
mlen = ntohs(pkt->msg.len);
if (bytes < (mlen + sizeof(pkt->eh))
|| bytes < NMRP_MIN_PKT_LEN
|| mlen < NMRP_HDR_LEN) {
fprintf(stderr, "Short packet (%d raw, %d message)\n",
(int)bytes, (int)mlen);
return 1;
} else if (mlen > sizeof(pkt->msg)) {
printf("Truncating %d byte message.\n", (int)mlen);
pkt->msg.len = htons(sizeof(pkt->msg));
}
return 0;
}
static int mac_parse(const char *str, uint8_t *hwaddr)
{
int i;
unsigned data[6];
sscanf(str, "%02x:%02x:%02x:%02x:%02x:%02x%n",
data, data + 1, data + 2, data + 3, data + 4, data + 5, &i);
if (i == strlen(str)) {
for (i = 0; i != 6; ++i) {
if (data[i] > 255) {
break;
}
hwaddr[i] = data[i] & 0xff;
}
if (i == 6) {
return 1;
}
}
return 0;
}
struct is_valid_ip_arg
{
struct in_addr *ipaddr;
struct in_addr *ipmask;
int result;
};
static int is_valid_ip_cb(struct ethsock_ip_callback_args *args)
{
#define SUBNET(x) ((x)->ipaddr->s_addr & (x)->ipmask->s_addr)
struct is_valid_ip_arg *arg = args->arg;
if (SUBNET(args) == SUBNET(arg)) {
arg->result = args->ipaddr->s_addr != arg->ipaddr->s_addr;
return 0;
}
return 1;
#undef SUBNET
}
static int is_valid_ip(struct ethsock *sock, struct in_addr *ipaddr,
struct in_addr *ipmask)
{
int status;
struct is_valid_ip_arg arg = {
.ipaddr = ipaddr,
.ipmask = ipmask,
.result = 0
};
status = ethsock_for_each_ip(sock, is_valid_ip_cb, &arg);
return status < 0 ? status : arg.result;
}
static void sigh(int sig)
{
g_interrupted = 1;
}
static const char *spinner = "\\|/-";
int nmrp_do(struct nmrpd_args *args)
{
struct nmrp_pkt tx, rx;
uint8_t *src, dest[6];
uint16_t region;
char *filename;
time_t beg;
int i, timeout, status, ulreqs, expect, upload_ok, autoip, ka_reqs, fake;
struct ethsock *sock;
struct ethsock_ip_undo *ip_undo = NULL;
struct ethsock_arp_undo *arp_undo = NULL;
uint32_t intf_addr = 0;
void (*sigh_orig)(int);
struct in_addr ipaddr;
struct in_addr ipmask;
if (args->op != NMRP_UPLOAD_FW) {
fprintf(stderr, "Operation not implemented.\n");
return 1;
}
if (!mac_parse(args->mac, dest)) {
fprintf(stderr, "Invalid MAC address '%s'.\n", args->mac);
return 1;
}
ipmask.s_addr = inet_addr(args->ipmask);
if (ipmask.s_addr == INADDR_NONE
|| netmask(bitcount(ipmask.s_addr)) != ipmask.s_addr) {
fprintf(stderr, "Invalid subnet mask '%s'.\n", args->ipmask);
return 1;
}
if (!args->ipaddr) {
autoip = true;
/* A random IP address. The MAC of the first device that was
* used to test this utility starts with a4:2b:8c, so we use
* 164 (0xa4) and 183 (0x2b + 0x8c).
*
* These addresses should not cause collisions on most networks,
* and if they do, the user is probably "poweruser" enough to
* be able to use the -a and -A options.
*/
args->ipaddr = "10.164.183.252";
if (!args->ipaddr_intf) {
args->ipaddr_intf = "10.164.183.253";
}
} else if (args->ipaddr_intf) {
autoip = true;
} else {
autoip = false;
}
if ((ipaddr.s_addr = inet_addr(args->ipaddr)) == INADDR_NONE) {
fprintf(stderr, "Invalid IP address '%s'.\n", args->ipaddr);
return 1;
}
if (args->ipaddr_intf && (intf_addr = inet_addr(args->ipaddr_intf)) == INADDR_NONE) {
fprintf(stderr, "Invalid IP address '%s'.\n", args->ipaddr_intf);
return 1;
}
if (args->file_local && strcmp(args->file_local, "-") && access(args->file_local, R_OK) == -1) {
fprintf(stderr, "Error accessing file '%s'.\n", args->file_local);
return 1;
}
if (args->file_remote) {
if (!tftp_is_valid_filename(args->file_remote)) {
fprintf(stderr, "Invalid remote filename '%s'.\n",
args->file_remote);
return 1;
}
}
if (args->region) {
region = to_region_code(args->region);
if (!region) {
fprintf(stderr, "Invalid region code '%s'.\n", args->region);
return 1;
}
} else {
region = 0;
}
status = 1;
sock = ethsock_create(args->intf, ETH_P_NMRP);
if (!sock) {
return 1;
}
sigh_orig = signal(SIGINT, sigh);
if (ethsock_is_unplugged(sock)) {
printf("Waiting for physical connection.\n");
bool unplugged = true;
time_t beg = time_monotonic();
while (!g_interrupted && (time_monotonic() - beg) < 20) {
if (!ethsock_is_unplugged(sock)) {
unplugged = false;
break;
}
}
if (unplugged) {
if (!g_interrupted) {
fprintf(stderr, "Error: Ethernet cable is unplugged.\n");
}
goto out;
}
}
if (!autoip) {
status = is_valid_ip(sock, &ipaddr, &ipmask);
if (status <= 0) {
if (!status) {
fprintf(stderr, "Address %s/%s cannot be used on interface %s.\n",
args->ipaddr, args->ipmask, args->intf);
}
goto out;
}
} else {
if (verbosity) {
printf("Adding %s to interface %s.\n", args->ipaddr_intf, args->intf);
}
if (ethsock_ip_add(sock, intf_addr, ipmask.s_addr, &ip_undo) != 0) {
goto out;
}
}
if (ethsock_set_timeout(sock, 200)) {
goto out;
}
src = ethsock_get_hwaddr(sock);
if (!src) {
goto out;
}
memcpy(tx.eh.ether_shost, src, 6);
memcpy(tx.eh.ether_dhost, dest, 6);
tx.eh.ether_type = htons(ETH_P_NMRP);
msg_mkadvertise(&tx.msg, "NTGR");
i = 0;
upload_ok = 0;
fake = 0;
timeout = args->blind ? 10 : NMRP_ADVERTISE_TIMEOUT;
beg = time_monotonic();
while (!g_interrupted) {
printf("\rAdvertising NMRP server on %s ... %c",
args->intf, spinner[i]);
fflush(stdout);
i = (i + 1) & 3;
if (pkt_send(sock, &tx) < 0) {
goto out;
}
status = pkt_recv(sock, &rx);
if (status == 0) {
if (memcmp(rx.eh.ether_dhost, src, 6) == 0) {
break;
} else if (verbosity) {
printf("\nIgnoring bogus response: %s -> %s.\n",
mac_to_str(rx.eh.ether_shost),
mac_to_str(rx.eh.ether_dhost));
}
} else if (status == 1) {
goto out;
} else {
/* because we don't want nmrpflash's exit status to be zero */
status = 1;
if ((time_monotonic() - beg) >= timeout) {
printf("\nNo response after %d seconds. ", timeout);
if (!args->blind) {
printf("Bailing out.\n");
goto out;
} else {
// we're blind, so fake a response from the MAC specified by -m
memcpy(rx.eh.ether_shost, dest, 6);
msg_init(&rx.msg, NMRP_C_CONF_REQ);
printf("Continuing blindly.");
fake = 1;
break;
}
}
}
}
printf("\n");
memcpy(tx.eh.ether_dhost, rx.eh.ether_shost, 6);
if (ethsock_arp_add(sock, rx.eh.ether_shost, ipaddr.s_addr, &arp_undo) != 0) {
goto out;
}
if (ethsock_set_timeout(sock, args->rx_timeout)) {
goto out;
}
expect = NMRP_C_CONF_REQ;
ulreqs = 0;
ka_reqs = 0;
while (!g_interrupted) {
if (expect != NMRP_C_NONE && rx.msg.code != expect) {
fprintf(stderr, "Received %s while waiting for %s!\n",
msg_code_str(rx.msg.code), msg_code_str(expect));
}
msg_init(&tx.msg, NMRP_C_NONE);
status = 1;
switch (rx.msg.code) {
case NMRP_C_ADVERTISE:
printf("Received NMRP advertisement from %s.\n",
mac_to_str(rx.eh.ether_shost));
status = 1;
goto out;
case NMRP_C_CONF_REQ:
msg_mkconfack(&tx.msg, ipaddr.s_addr, ipmask.s_addr, region);
expect = NMRP_C_TFTP_UL_REQ;
if (!fake) {
printf("Received configuration request from %s.\n",
mac_to_str(rx.eh.ether_shost));
}
printf("Sending configuration: %s/%d.\n",
args->ipaddr, bitcount(ipmask.s_addr));
break;
case NMRP_C_TFTP_UL_REQ:
if (!upload_ok) {
if (++ulreqs > 5) {
printf("Bailing out after %d upload requests.\n",
ulreqs);
tx.msg.code = NMRP_C_CLOSE_REQ;
break;
}
} else {
if (verbosity) {
printf("Ignoring extra upload request.\n");
}
ethsock_set_timeout(sock, args->ul_timeout);
tx.msg.code = NMRP_C_KEEP_ALIVE_REQ;
break;
}
filename = msg_filename(&rx.msg);
if (filename) {
if (!args->file_remote) {
args->file_remote = filename;
}
printf("Received upload request: filename '%s'.\n", filename);
} else if (!args->file_remote) {
args->file_remote = leafname(args->file_local);
if (!fake) {
printf("Received upload request without filename.\n");
}
}
status = 0;
if (args->tftpcmd) {
printf("Executing '%s' ... \n", args->tftpcmd);
setenv("IP", inet_ntoa(ipaddr), 1);
setenv("PORT", lltostr(args->port, 10), 1);
setenv("MAC", mac_to_str(rx.eh.ether_shost), 1);
setenv("NETMASK", inet_ntoa(ipmask), 1);
//setenv("FILENAME", args->file_remote ? args->file_remote : "", 1);
status = system(args->tftpcmd);
}
if (!status && args->file_local) {
if (!autoip) {
status = is_valid_ip(sock, &ipaddr, &ipmask);
if (status < 0) {
goto out;
} else if (!status) {
printf("IP address of %s has changed. Please assign a "
"static ip to the interface.\n", args->intf);
tx.msg.code = NMRP_C_CLOSE_REQ;
break;
}
}
if (verbosity) {
printf("Using remote filename '%s'.\n",
args->file_remote);
}
if (!strcmp(args->file_local, "-")) {
printf("Uploading from stdin ... ");
} else {
printf("Uploading %s ... ", leafname(args->file_local));
}
fflush(stdout);
if (!(status = tftp_put(args))) {
printf("OK\n");
}
}
if (!status) {
if (args->blind) {
goto out;
}
printf("Waiting for remote to respond.\n");
upload_ok = 1;
ethsock_set_timeout(sock, args->ul_timeout);
tx.msg.code = NMRP_C_KEEP_ALIVE_REQ;
expect = NMRP_C_NONE;
} else if (status == -2) {
expect = NMRP_C_TFTP_UL_REQ;
} else {
goto out;
}
break;
case NMRP_C_KEEP_ALIVE_REQ:
tx.msg.code = NMRP_C_KEEP_ALIVE_ACK;
ethsock_set_timeout(sock, args->ul_timeout);
printf("\rReceived keep-alive request (%d). ", ++ka_reqs);
break;
case NMRP_C_CLOSE_REQ:
tx.msg.code = NMRP_C_CLOSE_ACK;
break;
case NMRP_C_CLOSE_ACK:
status = 0;
goto out;
default:
fprintf(stderr, "Unknown message code 0x%02x!\n",
rx.msg.code);
msg_dump(&rx.msg);
}
if (tx.msg.code != NMRP_C_NONE) {
if (pkt_send(sock, &tx) != 0 || tx.msg.code == NMRP_C_CLOSE_REQ) {
goto out;
}
}
if (rx.msg.code == NMRP_C_CLOSE_REQ) {
if (ka_reqs) {
printf("\n");
}
printf("Remote finished. Closing connection.\n");
break;
}
status = pkt_recv(sock, &rx);
if (status) {
if (status == 2) {
if (!args->blind) {
fprintf(stderr, "Timeout while waiting for %s.\n",
msg_code_str(expect));
goto out;
}
// fake response
msg_init(&rx.msg, expect);
memcpy(rx.eh.ether_shost, tx.eh.ether_dhost, 6);
fake = 1;
} else {
goto out;
}
} else {
fake = 0;
}
ethsock_set_timeout(sock, args->rx_timeout);
}
if (!g_interrupted) {
status = 0;
if (ulreqs) {
printf("Reboot your device now.\n");
} else {
printf("No upload request received.\n");
}
}
out:
signal(SIGINT, sigh_orig);
ethsock_arp_del(sock, &arp_undo);
ethsock_ip_del(sock, &ip_undo);
ethsock_close(sock);
return status;
}
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