Linux etherhelper support.

This commit is contained in:
Dan Sumorok 2016-03-15 20:03:59 -04:00
parent fcc1598086
commit 7710322fd3
3 changed files with 709 additions and 1 deletions

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@ -0,0 +1,624 @@
/*
* etherhelpertool.c - Reads and writes raw ethernet packets usng bpf
* interface.
*
* Copyright (C) 2010, Daniel Sumorok
*
* Basilisk II (C) 1997-2008 Christian Bauer
*
* This program 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 2 of the License, or
* (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <ifaddrs.h>
#include <errno.h>
#include <sys/select.h>
#include <unistd.h>
#include <stdlib.h>
#include <net/if.h>
#include <sys/time.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <netpacket/packet.h>
#include <net/ethernet.h>
#include <fcntl.h>
#include <signal.h>
#include <linux/if_tun.h>
#include <strings.h>
#define STR_MAX 256
#define MAX_ARGV 10
static int remove_bridge = 0;
static const char *exec_name = "etherhelpertool";
static int main_loop(int sd, int use_bpf);
static int open_tap(char *ifname);
static int run_cmd(const char *cmd);
static void handler(int signum);
static int install_signal_handlers(void);
static void do_exit(void);
static int open_bpf(char *ifname);
int main(int argc, char **argv)
{
char *if_name;
int ret = 255;
int sd = -1;
int tapNum;
int use_bpf;
if (argc != 2) {
return 255;
}
if_name = argv[1];
do {
if (strncmp(if_name, "tap", 3) == 0) {
sd = open_tap(if_name);
use_bpf = 0;
} else {
sd = open_bpf(if_name);
use_bpf = 1;
}
if (sd < 0) {
fprintf(stderr, "%s: open device failed.\n",
exec_name);
ret = 253;
break;
}
if (install_signal_handlers() != 0) {
fprintf(stderr,
"%s: failed to install signal handers.\n",
exec_name);
ret = 252;
break;
}
ret = main_loop(sd, use_bpf);
close(sd);
} while (0);
do_exit();
return ret;
}
static int main_loop(int sd, int use_bpf)
{
fd_set readSet;
char *outgoing, *incoming;
unsigned short *out_len;
unsigned short *in_len;
int in_index, out_index;
u_int blen = 0;
int ret;
int fret = 0;
int pkt_len;
int frame_len;
int pad;
char c = 0;
blen = 4096;
incoming = malloc(blen);
if (incoming == NULL) {
fprintf(stderr,
"%s: malloc() failed.\n",
exec_name);
return -2;
}
outgoing = malloc(blen);
if (outgoing == NULL) {
free(outgoing);
fprintf(stderr,
"%s: malloc() failed.\n",
exec_name);
return -3;
}
in_index = 0;
out_index = 0;
out_len = (unsigned short *)outgoing;
/* Let our parent know we are ready for business. */
if(write(0, &c, 1) != 1) {
fprintf(stderr, "%s: Failed to notify main application: %s\n",
__func__, strerror(errno));
}
while (1) {
int i;
FD_ZERO(&readSet);
FD_SET(0, &readSet);
FD_SET(sd, &readSet);
ret = select(sd + 1, &readSet, NULL, NULL, NULL);
if (ret < 0) {
fprintf(stderr,
"%s: select() failed.\n",
exec_name);
fret = -4;
break;
}
if (FD_ISSET(0, &readSet)) {
if (out_index < 2) {
ret = read(0, outgoing + out_index, 2-out_index);
} else {
ret = read(0, outgoing + out_index, *out_len - out_index + 2);
}
if (ret < 1) {
if(ret < 0) {
fprintf(stderr,
"%s: read() failed.\n",
exec_name);
}
fret = -5;
break;
}
out_index += ret;
if (out_index > 1) {
if ((*out_len + 2) > blen) {
fret = -6;
break;
}
if (out_index == (*out_len + 2)) {
ret = write(sd, out_len + 1, *out_len);
if (ret != *out_len) {
fprintf(stderr,
"%s: write() failed.\n",
exec_name);
fret = -7;
break;
}
out_index = 0;
}
}
}
if (FD_ISSET(sd, &readSet)) {
in_len = (unsigned short *)incoming;
pkt_len = read(sd, in_len + 1, blen-2);
if (pkt_len < 14) {
fprintf(stderr,
"%s: read() returned %d.\n",
exec_name, pkt_len);
fret = -8;
break;
}
*in_len = pkt_len;
if (write(0, in_len, pkt_len + 2) < (pkt_len + 2)) {
fprintf(stderr,
"%s: write() failed\n",
exec_name);
fret = -10;
break;
}
}
}
free(incoming);
free(outgoing);
return fret;
}
static int open_tap(char *ifname)
{
char str[STR_MAX] = {0};
char ifstr[STR_MAX] = {0};
char *interface;
char *address = NULL;
char *netmask = NULL;
char *bridge = NULL;
char *bridged_if = NULL;
int sd;
snprintf(ifstr, STR_MAX, "%s", ifname);
interface = strtok(ifstr, "/");
bridge = strtok(NULL, "/");
if (bridge != NULL) {
bridged_if = strtok(NULL, "/");
}
interface = strtok(ifstr, ":");
address = strtok(NULL, ":");
if (address != NULL) {
netmask = strtok(NULL, ":");
}
snprintf(str, STR_MAX, "/dev/%s", interface);
sd = open(str, O_RDWR);
if (sd < 0) {
fprintf(stderr, "%s: Failed to open %s\n",
exec_name, interface);
return -1;
}
if (address == NULL) {
snprintf(str, STR_MAX, "/sbin/ifconfig %s up", interface);
} else if (netmask == NULL) {
snprintf(str, STR_MAX, "/sbin/ifconfig %s %s",
interface, address);
} else {
snprintf(str, STR_MAX, "/sbin/ifconfig %s %s netmask %s",
interface, address, netmask);
}
if (run_cmd(str) != 0) {
fprintf(stderr, "%s: Failed to configure %s\n",
exec_name, interface);
close(sd);
return -1;
}
if (bridge != NULL) {
/* Check to see if bridge is alread up */
snprintf(str, STR_MAX, "/sbin/ifconfig %s", bridge);
if (run_cmd(str) == 0) {
/* bridge is already up */
if (bridged_if != NULL) {
fprintf(stderr, "%s: Warning: %s already exists, so %s was not added.\n",
exec_name, bridge, bridged_if);
}
} else {
snprintf(str, STR_MAX, "/sbin/ifconfig %s create", bridge);
if (run_cmd(str) != 0) {
fprintf(stderr, "%s: Failed to create %s\n",
exec_name, bridge);
close(sd);
return -1;
}
remove_bridge = 1;
snprintf(str, STR_MAX, "/sbin/ifconfig %s up", bridge);
if (run_cmd(str) != 0) {
fprintf(stderr, "%s: Failed to open %s\n",
exec_name, bridge);
close(sd);
return -1;
}
if (bridged_if != NULL) {
snprintf(str, STR_MAX, "/sbin/ifconfig %s addm %s",
bridge, bridged_if);
if (run_cmd(str) != 0) {
fprintf(stderr, "%s: Failed to add %s to %s\n",
exec_name, bridged_if, bridge);
close(sd);
return -1;
}
}
snprintf(str, STR_MAX, "/sbin/ifconfig %s addm %s",
bridge, interface);
if (run_cmd(str) != 0) {
fprintf(stderr, "%s: Failed to add %s to %s\n",
exec_name, interface, bridge);
close(sd);
return -1;
}
}
}
return sd;
}
static int run_cmd(const char *cmd) {
char cmd_buffer[STR_MAX] = {0};
char *argv[MAX_ARGV + 1] = {0};
int i;
pid_t pid, waitpid;
int status = 0;
/* Collect arguments */
strncpy(cmd_buffer, cmd, STR_MAX-1);
argv[0] = strtok(cmd_buffer, " ");
for (i=1; i<MAX_ARGV; ++i) {
argv[i] = strtok(NULL, " ");
if (argv[i] == NULL) {
break;
}
}
/* Run sub process */
pid = fork();
if (pid == 0) {
/* Child process */
fclose(stdout);
fclose(stderr);
if (execve(argv[0], argv, NULL) < 0) {
perror("execve");
return -1;
}
} else {
/* Wait for child to exit */
waitpid = wait(&status);
if (waitpid < 0) {
perror("wait");
return -1;
}
if (status != 0) {
return -1;
}
}
return 0;
}
static void handler(int signum) {
do_exit();
exit(1);
}
static int install_signal_handlers() {
struct sigaction act = {0};
act.sa_handler = handler;
sigemptyset(&act.sa_mask);
if (sigaction(SIGINT, &act, NULL) != 0) {
return -1;
}
if (sigaction(SIGHUP, &act, NULL) != 0) {
return -1;
}
if (sigaction(SIGTERM, &act, NULL) != 0) {
return -1;
}
return 0;
}
static void do_exit() {
if (remove_bridge) {
run_cmd("/sbin/ifconfig bridge0 destroy");
}
}
static int open_bpf(char *ifname)
{
int sd;
struct sockaddr_ll sockaddr = {0};
struct ifreq ifreq = {0};
struct packet_mreq pmreq = {0};
socklen_t socklen = sizeof(struct packet_mreq);
sd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
if(sd < 0) {
perror("socket");
return -1;
}
strncpy(ifreq.ifr_name, ifname, IFNAMSIZ);
if(ioctl(sd, SIOCGIFINDEX, &ifreq) != 0) {
fprintf(stderr, "%s: ioctl(SIOCGIFINDEX): %s\n",
__func__, strerror(errno));
close(sd);
return -1;
}
pmreq.mr_ifindex = ifreq.ifr_ifindex;
pmreq.mr_type = PACKET_MR_PROMISC;
if(setsockopt(sd, SOL_PACKET, PACKET_ADD_MEMBERSHIP,
&pmreq, socklen) != 0) {
fprintf(stderr, "%s: setsockopt() failed: %s\n",
__func__, strerror(errno));
close(sd);
return -1;
}
sockaddr.sll_family = AF_PACKET;
sockaddr.sll_ifindex = ifreq.ifr_ifindex;
sockaddr.sll_protocol = htons(ETH_P_ALL);
if(bind(sd, (struct sockaddr *)&sockaddr,
sizeof(struct sockaddr_ll)) != 0) {
fprintf(stderr, "%s: bind failed: %s\n",
__func__, strerror(errno));
close(sd);
return -1;
}
return sd;
}
#if 0
static int retreive_auth_info(void);
static int retreive_auth_info(void)
{
AuthorizationRef aRef;
OSStatus status;
AuthorizationRights myRights;
AuthorizationRights *newRights;
AuthorizationItem *myItem;
AuthorizationItem myItems[1];
AuthorizationItemSet *mySet;
int i;
status = AuthorizationCopyPrivilegedReference(&aRef, kAuthorizationFlagDefaults);
if (status != errAuthorizationSuccess) {
return -1;
}
status = AuthorizationCopyInfo(aRef, NULL, &mySet);
if (status != errAuthorizationSuccess) {
AuthorizationFree(aRef, kAuthorizationFlagDestroyRights);
return -1;
}
myItems[0].name = "system.privilege.admin";
myItems[0].valueLength = 0;
myItems[0].value = NULL;
myItems[0].flags = 0;
myRights.count = sizeof (myItems) / sizeof (myItems[0]);
myRights.items = myItems;
status = AuthorizationCopyRights(aRef, &myRights, NULL,
kAuthorizationFlagExtendRights,
&newRights);
if (status != errAuthorizationSuccess) {
AuthorizationFreeItemSet(mySet);
AuthorizationFree(aRef, kAuthorizationFlagDestroyRights);
return -2;
}
AuthorizationFreeItemSet(newRights);
AuthorizationFreeItemSet(mySet);
AuthorizationFree(aRef, kAuthorizationFlagDestroyRights);
return 0;
}
static int open_tap(char *ifname)
{
char str[STR_MAX] = {0};
char ifstr[STR_MAX] = {0};
char *interface;
char *address = NULL;
char *netmask = NULL;
char *bridge = NULL;
char *bridged_if = NULL;
int sd;
snprintf(ifstr, STR_MAX, "%s", ifname);
interface = strtok(ifstr, "/");
bridge = strtok(NULL, "/");
if (bridge != NULL) {
bridged_if = strtok(NULL, "/");
}
interface = strtok(ifstr, ":");
address = strtok(NULL, ":");
if (address != NULL) {
netmask = strtok(NULL, ":");
}
snprintf(str, STR_MAX, "/dev/%s", interface);
sd = open(str, O_RDWR);
if (sd < 0) {
fprintf(stderr, "%s: Failed to open %s\n",
exec_name, interface);
return -1;
}
if (address == NULL) {
snprintf(str, STR_MAX, "/sbin/ifconfig %s up", interface);
} else if (netmask == NULL) {
snprintf(str, STR_MAX, "/sbin/ifconfig %s %s",
interface, address);
} else {
snprintf(str, STR_MAX, "/sbin/ifconfig %s %s netmask %s",
interface, address, netmask);
}
if (run_cmd(str) != 0) {
fprintf(stderr, "%s: Failed to configure %s\n",
exec_name, interface);
close(sd);
return -1;
}
if (bridge != NULL) {
/* Check to see if bridge is alread up */
snprintf(str, STR_MAX, "/sbin/ifconfig %s", bridge);
if (run_cmd(str) == 0) {
/* bridge is already up */
if (bridged_if != NULL) {
fprintf(stderr, "%s: Warning: %s already exists, so %s was not added.\n",
exec_name, bridge, bridged_if);
}
} else {
snprintf(str, STR_MAX, "/sbin/ifconfig %s create", bridge);
if (run_cmd(str) != 0) {
fprintf(stderr, "%s: Failed to create %s\n",
exec_name, bridge);
close(sd);
return -1;
}
remove_bridge = 1;
snprintf(str, STR_MAX, "/sbin/ifconfig %s up", bridge);
if (run_cmd(str) != 0) {
fprintf(stderr, "%s: Failed to open %s\n",
exec_name, bridge);
close(sd);
return -1;
}
if (bridged_if != NULL) {
snprintf(str, STR_MAX, "/sbin/ifconfig %s addm %s",
bridge, bridged_if);
if (run_cmd(str) != 0) {
fprintf(stderr, "%s: Failed to add %s to %s\n",
exec_name, bridged_if, bridge);
close(sd);
return -1;
}
}
snprintf(str, STR_MAX, "/sbin/ifconfig %s addm %s",
bridge, interface);
if (run_cmd(str) != 0) {
fprintf(stderr, "%s: Failed to add %s to %s\n",
exec_name, interface, bridge);
close(sd);
return -1;
}
}
}
return sd;
}
#endif

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@ -0,0 +1,58 @@
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <errno.h>
#define STR_MAX 1024
#define MAX_ARGV 10
FILE * run_tool(const char *if_name, const char *tool_name) {
char cmd_buffer[STR_MAX] = {0};
char * const argv[3] = {NULL, NULL, NULL};
int i;
pid_t pid, waitpid;
int status = 0;
int fds[2];
char c;
if(socketpair(PF_LOCAL, SOCK_STREAM, 0, fds) != 0) {
fprintf(stderr, "%s: socketpair() failed: %s\n",
__func__, strerror(errno));
return NULL;
}
((const char**)argv)[0] = tool_name;
((const char**)argv)[1] = if_name;
/* Run sub process */
pid = fork();
if (pid == 0) {
/* Child process */
fclose(stdout);
fclose(stdin);
dup2(fds[0], 0);
close(fds[1]);
close(fds[0]);
if (execve(tool_name, argv, NULL) < 0) {
perror("execve");
exit(1);
}
}
close(fds[0]);
if(read(fds[1], &c, 1) < 1) {
close(fds[1]);
return NULL;
}
return fdopen(fds[1], "rw");
}

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@ -43,7 +43,16 @@
#include <sys/socket.h>
#ifdef ENABLE_MACOSX_ETHERHELPER
#ifdef __APPLE__
#include <net/if_dl.h>
#endif
#ifdef __linux__
#include <linux/if_packet.h>
#endif
#include <sys/socket.h>
#include <ifaddrs.h>
#endif
@ -1140,8 +1149,13 @@ static int get_mac_address(const char* dev, unsigned char *addr)
{
struct ifaddrs *ifaddrs, *next;
int ret = -1;
#ifdef __APPLE__
struct sockaddr_dl *sa;
#endif
#ifdef __linux__
struct sockaddr_ll *sa;
#endif
if (getifaddrs(&ifaddrs) != 0) {
perror("getifaddrs");
return -1;
@ -1150,6 +1164,7 @@ static int get_mac_address(const char* dev, unsigned char *addr)
next = ifaddrs;
while (next != NULL) {
switch (next->ifa_addr->sa_family) {
#ifdef __APPLE__
case AF_LINK:
if (!strcmp(dev, next->ifa_name)) {
sa = (struct sockaddr_dl *)next->ifa_addr;
@ -1157,6 +1172,17 @@ static int get_mac_address(const char* dev, unsigned char *addr)
ret = 0;
}
break;
#endif
#ifdef __linux__
case AF_PACKET:
if (!strcmp(dev, next->ifa_name)) {
sa = (struct sockaddr_ll *)next->ifa_addr;
memcpy(addr, sa->sll_addr, 6);
ret = 0;
}
break;
#endif
default:
break;
}
@ -1240,7 +1266,7 @@ static int read_packet()
}
index += ret;
if (index > 1) {
if (*pkt_len > (sizeof(packet_buffer) + 2)) {
fprintf(stderr, "%s: pkt_len (%d) too large.\n", __func__, *pkt_len);