to work around vmnet root/entitlement restrictions, add a stand-alone helper utility than can be setuid root.

vmnet_helper creates a vmnet connection then communicates back to GS+ via pipes to stdin/stdout and a simple binary messaging protocol.
This commit is contained in:
Kelvin Sherlock 2019-01-06 22:58:41 -05:00
parent 55de506812
commit 4a5d6effd5
7 changed files with 1027 additions and 5 deletions

View File

@ -134,6 +134,18 @@ SET_SOURCE_FILES_PROPERTIES(
MACOSX_PACKAGE_LOCATION Resources
)
if(APPLE)
add_custom_command(TARGET GSplus POST_BUILD
COMMAND ${CMAKE_COMMAND} -E copy_if_different
"${CMAKE_CURRENT_BINARY_DIR}/rawnet/vmnet_helper"
"${CMAKE_CURRENT_BINARY_DIR}/GSplus.app/Contents/MacOS/vmnet_helper"
# COMMAND sudo chown root "${CMAKE_CURRENT_BINARY_DIR}/GSplus.app/Contents/MacOS/vmnet_helper"
# COMMAND sudo chmod +s "${CMAKE_CURRENT_BINARY_DIR}/GSplus.app/Contents/MacOS/vmnet_helper"
DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/rawnet/vmnet_helper)
endif()
# SET_SOURCE_FILES_PROPERTIES(vmnet_helper PROPERTIES MACOSX_PACKAGE_LOCATION MacOS)
if (WITH_RAWNET)
target_link_libraries(GSplus rawnet)
endif()

View File

@ -2,7 +2,7 @@
if(WIN32)
set(rawnetarch rawnetarch_win32.c)
elseif(APPLE)
set(rawnetarch rawnetarch_darwin.c)
set(rawnetarch rawnetarch_vmnet_helper.c)
#set(rawnetarch rawnetarch_unix.c)
elseif(UNIX)
set(rawnetarch rawnetarch_unix.c)
@ -13,11 +13,16 @@ add_library(rawnet cs8900.c rawnet.c rawnetsupp.c rawnetarch.c ${rawnetarch})
target_compile_definitions(rawnet PUBLIC HAVE_RAWNET)
target_compile_definitions(rawnet PRIVATE CS8900_DEBUG RAWNET_DEBUG_FRAMES)
target_compile_options(rawnet PRIVATE -g)
if(WIN32)
target_link_libraries(rawnet ws2_32) # winsock2
elseif(APPLE)
#target_link_libraries(rawnet PRIVATE pcap)
target_link_libraries(rawnet PRIVATE "-framework vmnet")
#target_link_libraries(rawnet PRIVATE "-framework vmnet")
add_executable(vmnet_helper vmnet_helper.c)
target_link_libraries(vmnet_helper PRIVATE "-framework vmnet")
elseif(UNIX)
target_link_libraries(rawnet PRIVATE pcap)
endif()

View File

@ -77,10 +77,9 @@ char *rawnet_get_standard_interface(void)
return rawnet_arch_get_standard_interface();
}
extern int rawnet_status(void)
int rawnet_status(void)
{
return rawnet_arch_status();
}
#endif /* #ifdef HAVE_RAWNET */

View File

@ -121,7 +121,7 @@ int rawnet_arch_receive(uint8_t *pbuffer, int *plen, int *phashed,
assert((*plen & 1) == 0);
ok = rawnet_arch_read(pbuffer, *plen);
if (ok < 0) return 0;
if (ok <= 0) return 0;
if (ok & 1) ++ok;
*plen = ok;

View File

@ -50,6 +50,8 @@ int rawnet_arch_activate(const char *interface_name) {
* *MIGHT* re-use the previous MAC address.
*/
if (interface) return 1;
memset(interface_mac, 0, sizeof(interface_mac));
memset(interface_fake_mac, 0, sizeof(interface_fake_mac));
interface_status = 0;

View File

@ -0,0 +1,673 @@
/*
* OS X 10.10+
* vmnet support (clang -framework vmnet -framework Foundation)
*/
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <unistd.h>
#include <errno.h>
#include <spawn.h>
#include <err.h>
#include <signal.h>
#include <mach-o/dyld.h>
#include "rawnetarch.h"
#include "rawnetsupp.h"
enum {
MSG_QUIT,
MSG_STATUS,
MSG_READ,
MSG_WRITE
};
#define MAKE_MSG(msg, extra) (msg | ((extra) << 8))
static const uint8_t broadcast_mac[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
static uint8_t interface_mac[6];
static uint8_t interface_fake_mac[6];
static uint32_t interface_mtu;
static uint32_t interface_packet_size;
static uint8_t *interface_buffer = NULL;
static pid_t interface_pid = 0;
static int interface_pipe[2];
static pid_t safe_waitpid(pid_t pid, int *stat_loc, int options) {
for(;;) {
pid_t rv = waitpid(pid, stat_loc,options);
if (rv < 0 && errno == EINTR) continue;
return rv;
}
}
static ssize_t safe_read(void *data, size_t nbytes) {
for (;;) {
ssize_t rv = read(interface_pipe[0], data, nbytes);
if (rv < 0 && errno == EINTR) continue;
return rv;
}
}
static ssize_t safe_readv(const struct iovec *iov, int iovcnt) {
for(;;) {
ssize_t rv = readv(interface_pipe[0], iov, iovcnt);
if (rv < 0 && errno == EINTR) continue;
return rv;
}
}
static ssize_t safe_write(const void *data, size_t nbytes) {
for (;;) {
ssize_t rv = write(interface_pipe[1], data, nbytes);
if (rv < 0 && errno == EINTR) continue;
return rv;
}
}
static ssize_t safe_writev(const struct iovec *iov, int iovcnt) {
for(;;) {
ssize_t rv = writev(interface_pipe[1], iov, iovcnt);
if (rv < 0 && errno == EINTR) continue;
return rv;
}
}
/* block the sigpipe signal */
static int block_pipe(struct sigaction *oact) {
struct sigaction act;
memset(&act, 0, sizeof(act));
act.sa_handler = SIG_IGN;
act.sa_flags = SA_RESTART;
return sigaction(SIGPIPE, &act, oact);
}
static int restore_pipe(const struct sigaction *oact) {
return sigaction(SIGPIPE, oact, NULL);
}
#if 0
static int block_pipe(sigset_t *oldset) {
sigset_t set;
sigemptyset(&set);
sigaddset(&set, SIGPIPE);
sigaddset(&set, SIGCHLD);
return sigprocmask(SIG_BLOCK, &set, oldset);
}
#endif
static int check_child_status(void) {
pid_t pid;
int stat;
pid = safe_waitpid(interface_pid, &stat, WNOHANG);
if (pid < 0 && errno == ECHILD) {
fprintf(stderr, "child process does not exist.\n");
close(interface_pipe[0]);
close(interface_pipe[1]);
interface_pid = 0;
return 0;
}
if (pid == interface_pid) {
if (WIFEXITED(stat)) fprintf(stderr, "child process exited.\n");
if (WIFSIGNALED(stat)) fprintf(stderr, "child process signalled.\n");
close(interface_pipe[0]);
close(interface_pipe[1]);
interface_pid = 0;
return 0;
}
return 1;
}
static char *get_relative_path(const char *leaf) {
uint32_t size = 0;
char *buffer = 0;
int ok;
char *cp;
int l;
l = strlen(leaf);
ok = _NSGetExecutablePath(NULL, &size);
size += l + 1;
buffer = malloc(size);
if (buffer) {
ok = _NSGetExecutablePath(buffer, &size);
if (ok < 0) {
free(buffer);
return NULL;
}
cp = strrchr(buffer, '/');
if (cp)
strcpy(cp + 1 , leaf);
else {
free(buffer);
buffer = NULL;
}
}
return buffer;
}
int rawnet_arch_init(void) {
//interface = NULL;
return 1;
}
void rawnet_arch_pre_reset(void) {
/* NOP */
}
void rawnet_arch_post_reset(void) {
/* NOP */
}
int rawnet_arch_activate(const char *interface_name) {
int ok;
posix_spawn_file_actions_t actions;
posix_spawnattr_t attr;
char *argv[] = { "vmnet_helper", NULL };
char *path = NULL;
int pipe_stdin[2];
int pipe_stdout[2];
struct sigaction oldaction;
if (interface_pid > 0) return 1;
/* fd[0] = read, fd[1] = write */
ok = pipe(pipe_stdin);
if (ok < 0) { warn("pipe"); return 0; }
ok = pipe(pipe_stdout);
if (ok < 0) { warn("pipe"); return 0; }
block_pipe(&oldaction);
posix_spawn_file_actions_init(&actions);
posix_spawnattr_init(&attr);
posix_spawn_file_actions_adddup2(&actions, pipe_stdin[0], STDIN_FILENO);
posix_spawn_file_actions_adddup2(&actions, pipe_stdout[1], STDOUT_FILENO);
posix_spawn_file_actions_addclose(&actions, pipe_stdin[0]);
posix_spawn_file_actions_addclose(&actions, pipe_stdin[1]);
posix_spawn_file_actions_addclose(&actions, pipe_stdout[0]);
posix_spawn_file_actions_addclose(&actions, pipe_stdout[1]);
path = get_relative_path("vmnet_helper");
ok = posix_spawn(&interface_pid, path, &actions, &attr, argv, NULL);
free(path);
posix_spawn_file_actions_destroy(&actions);
posix_spawnattr_destroy(&attr);
close(pipe_stdin[0]);
close(pipe_stdout[1]);
/* posix spawn returns 0 on success, error code on failure. */
if (ok != 0) {
fprintf(stderr, "posix_spawn vmnet_helper failed: %d\n", ok);
close(pipe_stdin[1]);
close(pipe_stdout[0]);
interface_pid = -1;
return 0;
}
interface_pipe[0] = pipe_stdout[0];
interface_pipe[1] = pipe_stdin[1];
/* now get the mac/mtu/etc */
uint32_t msg = MAKE_MSG(MSG_STATUS, 0);
ok = safe_write(&msg, 4);
if (ok != 4) goto fail;
ok = safe_read(&msg, 4);
if (ok != 4) goto fail;
if (msg != MAKE_MSG(MSG_STATUS, 6 + 4 + 4)) goto fail;
struct iovec iov[3];
iov[0].iov_len = 6;
iov[0].iov_base = interface_mac;
iov[1].iov_len = 4;
iov[1].iov_base = &interface_mtu;
iov[2].iov_len = 4;
iov[2].iov_base = &interface_packet_size;
ok = safe_readv(iov, 3);
if (ok != 6 + 4 + 4) goto fail;
/* sanity check */
/* expect MTU = 1500, packet_size = 1518 */
if (interface_packet_size < 256) {
interface_packet_size = 1518;
}
interface_buffer = malloc(interface_packet_size);
if (!interface_buffer) goto fail;
restore_pipe(&oldaction);
return 1;
fail:
close(interface_pipe[0]);
close(interface_pipe[1]);
safe_waitpid(interface_pid, NULL, 0);
interface_pid = 0;
restore_pipe(&oldaction);
return 0;
}
void rawnet_arch_deactivate(void) {
if (interface_pid) {
close(interface_pipe[0]);
close(interface_pipe[1]);
for(;;) {
int ok = waitpid(interface_pid, NULL, 0);
if (ok < 0 && errno == EINTR) continue;
break;
}
interface_pid = 0;
}
free(interface_buffer);
interface_buffer = NULL;
}
void rawnet_arch_set_mac(const uint8_t mac[6]) {
#ifdef RAWNET_DEBUG_ARCH
log_message( rawnet_arch_log, "New MAC address set: %02X:%02X:%02X:%02X:%02X:%02X.", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5] );
#endif
memcpy(interface_fake_mac, mac, 6);
}
void rawnet_arch_set_hashfilter(const uint32_t hash_mask[2]) {
/* NOP */
}
void rawnet_arch_recv_ctl(int bBroadcast, int bIA, int bMulticast, int bCorrect, int bPromiscuous, int bIAHash) {
/* NOP */
}
void rawnet_arch_line_ctl(int bEnableTransmitter, int bEnableReceiver) {
/* NOP */
}
enum {
eth_dest = 0, // destination address
eth_src = 6, // source address
eth_type = 12, // packet type
eth_data = 14, // packet data
};
enum {
ip_ver_ihl = 0,
ip_tos = 1,
ip_len = 2,
ip_id = 4,
ip_frag = 6,
ip_ttl = 8,
ip_proto = 9,
ip_header_cksum = 10,
ip_src = 12,
ip_dest = 16,
ip_data = 20,
};
enum {
udp_source = 0, // source port
udp_dest = 2, // destination port
udp_len = 4, // length
udp_cksum = 6, // checksum
udp_data = 8, // total length udp header
};
enum {
bootp_op = 0, // operation
bootp_hw = 1, // hardware type
bootp_hlen = 2, // hardware len
bootp_hp = 3, // hops
bootp_transid = 4, // transaction id
bootp_secs = 8, // seconds since start
bootp_flags = 10, // flags
bootp_ipaddr = 12, // ip address knwon by client
bootp_ipclient = 16, // client ip from server
bootp_ipserver = 20, // server ip
bootp_ipgateway = 24, // gateway ip
bootp_client_hrd = 28, // client mac address
bootp_spare = 34,
bootp_host = 44,
bootp_fname = 108,
bootp_data = 236, // total length bootp packet
};
enum {
arp_hw = 14, // hw type (eth = 0001)
arp_proto = 16, // protocol (ip = 0800)
arp_hwlen = 18, // hw addr len (eth = 06)
arp_protolen = 19, // proto addr len (ip = 04)
arp_op = 20, // request = 0001, reply = 0002
arp_shw = 22, // sender hw addr
arp_sp = 28, // sender proto addr
arp_thw = 32, // target hw addr
arp_tp = 38, // target protoaddr
arp_data = 42, // total length of packet
};
enum {
dhcp_discover = 1,
dhcp_offer = 2,
dhcp_request = 3,
dhcp_decline = 4,
dhcp_pack = 5,
dhcp_nack = 6,
dhcp_release = 7,
dhcp_inform = 8,
};
static uint8_t oo[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
static uint8_t ff[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
static int is_arp(const uint8_t *packet, unsigned size) {
return size == arp_data
&& packet[12] == 0x08 && packet[13] == 0x06 /* ARP */
&& packet[14] == 0x00 && packet[15] == 0x01 /* ethernet */
&& packet[16] == 0x08 && packet[17] == 0x00 /* ipv4 */
&& packet[18] == 0x06 /* hardware size */
&& packet[19] == 0x04 /* protocol size */
;
}
static int is_broadcast(const uint8_t *packet, unsigned size) {
return !memcmp(packet + 0, ff, 6);
}
static int is_unicast(const uint8_t *packet, unsigned size) {
return (*packet & 0x01) == 0;
}
static int is_multicast(const uint8_t *packet, unsigned size) {
return (*packet & 0x01) == 0x01 && !is_broadcast(packet, size);
}
static int is_dhcp_out(const uint8_t *packet, unsigned size) {
static uint8_t cookie[] = { 0x63, 0x82, 0x53, 0x63 };
return size >= 282
//&& !memcmp(&packet[0], ff, 6) /* broadcast */
&& packet[12] == 0x08 && packet[13] == 0x00
&& packet[14] == 0x45 /* version 4 */
&& packet[23] == 0x11 /* UDP */
//&& !memcmp(&packet[26], oo, 4) /* source ip */
//&& !memcmp(&packet[30], ff, 4) /* dest ip */
&& packet[34] == 0x00 && packet[35] == 0x44 /* source port */
&& packet[36] == 0x00 && packet[37] == 0x43 /* dest port */
//&& packet[44] == 0x01 /* dhcp boot req */
&& packet[43] == 0x01 /* ethernet */
&& packet[44] == 0x06 /* 6 byte mac */
&& !memcmp(&packet[278], cookie, 4)
;
}
static int is_dhcp_in(const uint8_t *packet, unsigned size) {
static uint8_t cookie[] = { 0x63, 0x82, 0x53, 0x63 };
return size >= 282
//&& !memcmp(&packet[0], ff, 6) /* broadcast */
&& packet[12] == 0x08 && packet[13] == 0x00
&& packet[14] == 0x45 /* version 4 */
&& packet[23] == 0x11 /* UDP */
//&& !memcmp(&packet[26], oo, 4) /* source ip */
//&& !memcmp(&packet[30], ff, 4) /* dest ip */
&& packet[34] == 0x00 && packet[35] == 0x43 /* source port */
&& packet[36] == 0x00 && packet[37] == 0x44 /* dest port */
//&& packet[44] == 0x01 /* dhcp boot req */
&& packet[43] == 0x01 /* ethernet */
&& packet[44] == 0x06 /* 6 byte mac */
&& !memcmp(&packet[278], cookie, 4)
;
}
static unsigned ip_checksum(const uint8_t *packet) {
unsigned x = 0;
unsigned i;
for (i = 0; i < ip_data; i += 2) {
if (i == ip_header_cksum) continue;
x += packet[eth_data + i + 0 ] << 8;
x += packet[eth_data + i + 1];
}
/* add the carry */
x += x >> 16;
x &= 0xffff;
return ~x & 0xffff;
}
static void fix_incoming_packet(uint8_t *packet, unsigned size, const uint8_t real_mac[6], const uint8_t fake_mac[6]) {
if (memcmp(packet + 0, real_mac, 6) == 0)
memcpy(packet + 0, fake_mac, 6);
/* dhcp request - fix the hardware address */
if (is_unicast(packet, size) && is_dhcp_in(packet, size)) {
if (!memcmp(packet + 70, real_mac, 6))
memcpy(packet + 70, fake_mac, 6);
return;
}
}
static void fix_outgoing_packet(uint8_t *packet, unsigned size, const uint8_t real_mac[6], const uint8_t fake_mac[6]) {
if (memcmp(packet + 6, fake_mac, 6) == 0)
memcpy(packet + 6, real_mac, 6);
if (is_arp(packet, size)) {
/* sender mac address */
if (!memcmp(packet + 22, fake_mac, 6))
memcpy(packet + 22, real_mac, 6);
return;
}
/* dhcp request - fix the hardware address */
if (is_broadcast(packet, size) && is_dhcp_out(packet, size)) {
if (!memcmp(packet + 70, fake_mac, 6))
memcpy(packet + 70, real_mac, 6);
return;
}
}
int rawnet_arch_read(void *buffer, int nbyte) {
uint32_t msg;
int ok;
int xfer;
struct sigaction oldaction;
if (interface_pid <= 0) return -1;
block_pipe(&oldaction);
msg = MAKE_MSG(MSG_READ, 0);
ok = safe_write(&msg, 4);
if (ok != 4) goto fail;
ok = safe_read(&msg, 4);
if (ok != 4) goto fail;
if ((msg & 0xff) != MSG_READ) goto fail;
xfer = msg >> 8;
if (xfer > interface_packet_size) {
fprintf(stderr, "packet size too big: %d\n", xfer);
/* drain the message ... */
while (xfer) {
int count = interface_packet_size;
if (count > xfer) count = xfer;
ok = safe_read(interface_buffer, count);
if (ok < 0) goto fail;
xfer -= ok;
}
return -1;
}
if (xfer == 0) return -1;
ok = safe_read(interface_buffer, xfer);
if (ok != xfer) goto fail;
fix_incoming_packet(interface_buffer, xfer, interface_mac, interface_fake_mac);
if (!is_multicast(interface_buffer, xfer)) { /* multicast crap */
fprintf(stderr, "\nrawnet_arch_receive: %u\n", (unsigned)xfer);
rawnet_hexdump(interface_buffer, xfer);
}
if (xfer > nbyte) xfer = nbyte;
memcpy(buffer, interface_buffer, xfer);
restore_pipe(&oldaction);
return xfer;
fail:
/* check if process still ok? */
check_child_status();
restore_pipe(&oldaction);
return -1;
}
int rawnet_arch_write(const void *buffer, int nbyte) {
int ok;
uint32_t msg;
struct iovec iov[2];
struct sigaction oldaction;
if (interface_pid <= 0) return -1;
if (nbyte <= 0) return 0;
if (nbyte > interface_packet_size) {
log_message(rawnet_arch_log, "packet is too big: %d", nbyte);
return -1;
}
/* copy the buffer and fix the source mac address. */
memcpy(interface_buffer, buffer, nbyte);
fix_outgoing_packet(interface_buffer, nbyte, interface_mac, interface_fake_mac);
fprintf(stderr, "\nrawnet_arch_transmit: %u\n", (unsigned)nbyte);
rawnet_hexdump(interface_buffer, nbyte);
block_pipe(&oldaction);
msg = MAKE_MSG(MSG_WRITE, nbyte);
iov[0].iov_base = &msg;
iov[0].iov_len = 4;
iov[1].iov_base = interface_buffer;
iov[1].iov_len = nbyte;
ok = safe_writev(iov, 2);
if (ok != 4 + nbyte) goto fail;
ok = safe_read(&msg, 4);
if (ok != 4) goto fail;
if (msg != MAKE_MSG(MSG_WRITE, nbyte)) goto fail;
restore_pipe(&oldaction);
return nbyte;
fail:
check_child_status();
restore_pipe(&oldaction);
return -1;
}
static unsigned adapter_index = 0;
int rawnet_arch_enumadapter_open(void) {
adapter_index = 0;
return 1;
}
int rawnet_arch_enumadapter(char **ppname, char **ppdescription) {
if (adapter_index == 0) {
++adapter_index;
if (ppname) *ppname = lib_stralloc("vmnet");
if (ppdescription) *ppdescription = lib_stralloc("vmnet");
return 1;
}
return 0;
}
int rawnet_arch_enumadapter_close(void) {
return 1;
}
char *rawnet_arch_get_standard_interface(void) {
return lib_stralloc("vmnet");
}
int rawnet_arch_get_mtu(void) {
return interface_pid > 0 ? interface_mtu : -1;
}
int rawnet_arch_get_mac(uint8_t mac[6]) {
if (interface_pid > 0) {
memcpy(mac, interface_mac, 6);
return 1;
}
return -1;
}
int rawnet_arch_status(void) {
return interface_pid > 0 ? 1 : 0;
}

331
src/rawnet/vmnet_helper.c Normal file
View File

@ -0,0 +1,331 @@
/* vmnet helper */
/* because it needs root permissions ... sigh */
/*
* basicly... run as root, read messages from stdin, write to stdout.
*/
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <unistd.h>
#include <vmnet/vmnet.h>
#include <errno.h>
#include <err.h>
static interface_ref interface;
static uint8_t interface_mac[6];
static long interface_mtu;
static long interface_packet_size;
static vmnet_return_t interface_status;
static size_t buffer_size = 0;
static uint8_t *buffer = NULL;
enum {
MSG_QUIT,
MSG_STATUS,
MSG_READ,
MSG_WRITE
};
#define MAKE_MSG(msg, extra) (msg | ((extra) << 8))
ssize_t safe_read(void *buffer, size_t nbyte) {
ssize_t rv;
for(;;) {
rv = read(STDIN_FILENO, buffer, nbyte);
if (rv < 0) {
if (errno == EINTR) continue;
err(1, "read");
}
break;
}
return rv;
}
ssize_t safe_readv(const struct iovec *iov, int iovcnt) {
ssize_t rv;
for(;;) {
rv = readv(STDIN_FILENO, iov, iovcnt);
if (rv < 0) {
if (errno == EINTR) continue;
err(1, "readv");
}
break;
}
return rv;
}
ssize_t safe_write(const void *buffer, size_t nbyte) {
ssize_t rv;
for(;;) {
rv = write(STDOUT_FILENO, buffer, nbyte);
if (rv < 0) {
if (errno == EINTR) continue;
err(1, "write");
}
break;
}
return rv;
}
ssize_t safe_writev(const struct iovec *iov, int iovcnt) {
ssize_t rv;
for(;;) {
rv = writev(STDOUT_FILENO, iov, iovcnt);
if (rv < 0) {
if (errno == EINTR) continue;
err(1, "writev");
}
break;
}
return rv;
}
void msg_status(uint32_t size) {
struct iovec iov[4];
uint32_t msg = MAKE_MSG(MSG_STATUS, 6 + 4 + 4);
iov[0].iov_len = 4;
iov[0].iov_base = &msg;
iov[1].iov_len = 6;
iov[1].iov_base = interface_mac;
iov[2].iov_len = 4;
iov[2].iov_base = &interface_mtu;
iov[3].iov_len = 4;
iov[3].iov_base = &interface_packet_size;
safe_writev(iov, 4);
}
int classify_mac(uint8_t *mac) {
if ((mac[0] & 0x01) == 0) return 1; /* unicast */
if (memcmp(mac, "\xff\xff\xff\xff\xff\xff", 6) == 0) return 0xff; /* broadcast */
return 2; /* multicast */
}
void msg_read(uint32_t flags) {
/* flag to block broadcast, multicast, etc? */
int count = 1;
int xfer;
vmnet_return_t st;
struct vmpktdesc v;
struct iovec iov[2];
uint32_t msg;
for(;;) {
int type;
iov[0].iov_base = buffer;
iov[0].iov_len = interface_packet_size;
v.vm_pkt_size = interface_packet_size;
v.vm_pkt_iov = iov;
v.vm_pkt_iovcnt = 1;
v.vm_flags = 0;
count = 1;
st = vmnet_read(interface, &v, &count);
if (st != VMNET_SUCCESS) errx(1, "vmnet_read");
if (count < 1) break;
/* todo -- skip multicast messages based on flag? */
type = classify_mac(buffer);
if (type == 2) continue; /* multicast */
break;
}
xfer = count == 1 ? v.vm_pkt_size : 0;
msg = MAKE_MSG(MSG_READ, xfer);
iov[0].iov_len = 4;
iov[0].iov_base = &msg;
iov[1].iov_len = xfer;
iov[1].iov_base = buffer;
safe_writev(iov, count == 1 ? 2 : 1);
}
void msg_write(uint32_t size) {
ssize_t ok;
int count = 1;
vmnet_return_t st;
struct vmpktdesc v;
struct iovec iov;
uint32_t msg;
if (size > interface_packet_size) errx(1, "packet too big");
for(;;) {
ok = safe_read(buffer, size);
if (ok < 0) err(1,"read");
if (ok != size) errx(1,"message truncated");
break;
}
iov.iov_base = buffer;
iov.iov_len = size;
v.vm_pkt_size = size;
v.vm_pkt_iov = &iov;
v.vm_pkt_iovcnt = 1;
v.vm_flags = 0;
st = vmnet_write(interface, &v, &count);
if (st != VMNET_SUCCESS) errx(1, "vmnet_write");
msg = MAKE_MSG(MSG_WRITE, size);
iov.iov_len = 4;
iov.iov_base = &msg;
safe_writev(&iov, 1);
}
void startup(void) {
xpc_object_t dict;
dispatch_queue_t q;
dispatch_semaphore_t sem;
memset(interface_mac, 0, sizeof(interface_mac));
interface_status = 0;
interface_mtu = 0;
interface_packet_size = 0;
dict = xpc_dictionary_create(NULL, NULL, 0);
xpc_dictionary_set_uint64(dict, vmnet_operation_mode_key, VMNET_SHARED_MODE);
sem = dispatch_semaphore_create(0);
q = dispatch_get_global_queue(QOS_CLASS_UTILITY, 0);
interface = vmnet_start_interface(dict, q, ^(vmnet_return_t status, xpc_object_t params){
interface_status = status;
if (status == VMNET_SUCCESS) {
const char *cp;
cp = xpc_dictionary_get_string(params, vmnet_mac_address_key);
fprintf(stderr, "vmnet mac: %s\n", cp);
sscanf(cp, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx",
&interface_mac[0],
&interface_mac[1],
&interface_mac[2],
&interface_mac[3],
&interface_mac[4],
&interface_mac[5]
);
interface_mtu = xpc_dictionary_get_uint64(params, vmnet_mtu_key);
interface_packet_size = xpc_dictionary_get_uint64(params, vmnet_max_packet_size_key);
fprintf(stderr, "vmnet mtu: %u\n", (unsigned)interface_mtu);
fprintf(stderr, "vmnet packet size: %u\n", (unsigned)interface_packet_size);
}
dispatch_semaphore_signal(sem);
});
dispatch_semaphore_wait(sem, DISPATCH_TIME_FOREVER);
if (interface_status == VMNET_SUCCESS) {
buffer_size = (interface_packet_size * 2 + 1023) & ~1023;
buffer = (uint8_t *)malloc(buffer_size);
} else {
if (interface) {
vmnet_stop_interface(interface, q, ^(vmnet_return_t status){
dispatch_semaphore_signal(sem);
});
dispatch_semaphore_wait(sem, DISPATCH_TIME_FOREVER);
interface = NULL;
}
errx(1,"vmnet_start_interface failed");
}
dispatch_release(sem);
xpc_release(dict);
}
void shutdown(void) {
dispatch_queue_t q;
dispatch_semaphore_t sem;
if (interface) {
sem = dispatch_semaphore_create(0);
q = dispatch_get_global_queue(QOS_CLASS_UTILITY, 0);
vmnet_stop_interface(interface, q, ^(vmnet_return_t status){
dispatch_semaphore_signal(sem);
});
dispatch_semaphore_wait(sem, DISPATCH_TIME_FOREVER);
dispatch_release(sem);
interface = NULL;
interface_status = 0;
}
free(buffer);
buffer = NULL;
buffer_size = 0;
}
int main(int argc, char **argv) {
uint32_t msg;
uint32_t extra;
ssize_t ok;
startup();
for(;;) {
ok = safe_read(&msg, 4);
if (ok == 0) break;
if (ok != 4) errx(1,"read msg");
extra = msg >> 8;
msg = msg & 0xff;
switch(msg) {
case MSG_STATUS:
msg_status(extra);
break;
case MSG_QUIT:
shutdown();
exit(0);
case MSG_READ:
msg_read(extra);
break;
case MSG_WRITE:
msg_write(extra);
break;
}
}
shutdown();
exit(0);
}