wg: support text-based ipc

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
This commit is contained in:
Jason A. Donenfeld 2017-05-15 23:24:48 +02:00
parent c3b2dbcdb0
commit 945fae0c7c
8 changed files with 320 additions and 130 deletions

View File

@ -15,7 +15,7 @@
#include "config.h"
#include "ipc.h"
#include "base64.h"
#include "encoding.h"
#define COMMENT_CHAR '#'
@ -171,14 +171,12 @@ static inline bool parse_endpoint(struct sockaddr *endpoint, const char *value)
fprintf(stderr, "Unable to find matching brace of endpoint: `%s`\n", value);
return false;
}
*end = '\0';
++end;
if (*end != ':' || !*(end + 1)) {
*end++ = '\0';
if (*end++ != ':' || !*end) {
free(mutable);
fprintf(stderr, "Unable to find port of endpoint: `%s`\n", value);
return false;
}
++end;
} else {
begin = mutable;
end = strrchr(mutable, ':');
@ -187,8 +185,7 @@ static inline bool parse_endpoint(struct sockaddr *endpoint, const char *value)
fprintf(stderr, "Unable to find port of endpoint: `%s`\n", value);
return false;
}
*end = '\0';
++end;
*end++ = '\0';
}
for (unsigned int timeout = 1000000; timeout < 90000000; timeout = timeout * 3 / 2) {

View File

@ -1,12 +1,12 @@
/* Copyright (C) 2015-2017 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*
* This is a specialized constant-time base64 implementation that resists side-channel attacks.
* This is a specialized constant-time base64/hex implementation that resists side-channel attacks.
*/
#include <string.h>
#include "base64.h"
#include "encoding.h"
static inline void encode(char dest[4], const uint8_t src[3])
static inline void encode_base64(char dest[4], const uint8_t src[3])
{
const uint8_t input[] = { (src[0] >> 2) & 63, ((src[0] << 4) | (src[1] >> 4)) & 63, ((src[1] << 2) | (src[2] >> 6)) & 63, src[2] & 63 };
for (unsigned int i = 0; i < 4; ++i)
@ -22,13 +22,13 @@ void key_to_base64(char base64[static WG_KEY_LEN_BASE64], const uint8_t key[stat
{
unsigned int i;
for (i = 0; i < WG_KEY_LEN / 3; ++i)
encode(&base64[i * 4], &key[i * 3]);
encode(&base64[i * 4], (const uint8_t[]){ key[i * 3 + 0], key[i * 3 + 1], 0 });
encode_base64(&base64[i * 4], &key[i * 3]);
encode_base64(&base64[i * 4], (const uint8_t[]){ key[i * 3 + 0], key[i * 3 + 1], 0 });
base64[WG_KEY_LEN_BASE64 - 2] = '=';
base64[WG_KEY_LEN_BASE64 - 1] = '\0';
}
static inline int decode(const char src[4])
static inline int decode_base64(const char src[4])
{
int val = 0;
for (unsigned int i = 0; i < 4; ++i)
@ -50,17 +50,52 @@ bool key_from_base64(uint8_t key[static WG_KEY_LEN], const char *base64)
return false;
for (i = 0; i < WG_KEY_LEN / 3; ++i) {
val = decode(&base64[i * 4]);
val = decode_base64(&base64[i * 4]);
if (val < 0)
return false;
key[i * 3 + 0] = (val >> 16) & 0xff;
key[i * 3 + 1] = (val >> 8) & 0xff;
key[i * 3 + 2] = val & 0xff;
}
val = decode((const char[]){ base64[i * 4 + 0], base64[i * 4 + 1], base64[i * 4 + 2], 'A' });
val = decode_base64((const char[]){ base64[i * 4 + 0], base64[i * 4 + 1], base64[i * 4 + 2], 'A' });
if (val < 0 || val & 0xff)
return false;
key[i * 3 + 0] = (val >> 16) & 0xff;
key[i * 3 + 1] = (val >> 8) & 0xff;
return true;
}
void key_to_hex(char hex[static WG_KEY_LEN_HEX], const uint8_t key[static WG_KEY_LEN])
{
unsigned int i;
for (i = 0; i < WG_KEY_LEN; ++i) {
hex[i * 2] = 87U + (key[i] >> 4) + ((((key[i] >> 4) - 10U) >> 8) & ~38U);
hex[i * 2 + 1] = 87U + (key[i] & 0xf) + ((((key[i] & 0xf) - 10U) >> 8) & ~38U);
}
hex[i * 2] = '\0';
}
bool key_from_hex(uint8_t key[static WG_KEY_LEN], const char *hex)
{
uint8_t i, c, c_acc = 0, c_alpha0, c_alpha, c_num0, c_num, c_val, state = 0;
if (strlen(hex) != WG_KEY_LEN_HEX - 1)
return false;
for (i = 0; i < WG_KEY_LEN_HEX - 1; ++i) {
c = (uint8_t)hex[i];
c_num = c ^ 48U;
c_num0 = (c_num - 10U) >> 8;
c_alpha = (c & ~32U) - 55U;
c_alpha0 = ((c_alpha - 10U) ^ (c_alpha - 16U)) >> 8;
if (!(c_num0 | c_alpha0))
return false;
c_val = (c_num0 & c_num) | (c_alpha0 & c_alpha);
if (!state)
c_acc = c_val * 16U;
else
key[i / 2] = c_acc | c_val;
state = ~state;
}
return true;
}

View File

@ -1,15 +1,19 @@
/* Copyright (C) 2015-2017 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. */
#ifndef BASE64_H
#define BASE64_H
#ifndef ENCODING_H
#define ENCODING_H
#include <stdbool.h>
#include <stdint.h>
#include "../uapi.h"
#define WG_KEY_LEN_BASE64 ((((WG_KEY_LEN) + 2) / 3) * 4 + 1)
#define WG_KEY_LEN_HEX (WG_KEY_LEN * 2 + 1)
void key_to_base64(char base64[static WG_KEY_LEN_BASE64], const uint8_t key[static WG_KEY_LEN]);
bool key_from_base64(uint8_t key[static WG_KEY_LEN], const char *base64);
void key_to_hex(char hex[static WG_KEY_LEN_HEX], const uint8_t key[static WG_KEY_LEN]);
bool key_from_hex(uint8_t key[static WG_KEY_LEN], const char *hex);
#endif

View File

@ -12,7 +12,7 @@
#endif
#include "curve25519.h"
#include "base64.h"
#include "encoding.h"
#include "subcommands.h"
static inline ssize_t get_random_bytes(uint8_t *out, size_t len)

358
src/ipc.c
View File

@ -19,14 +19,19 @@
#include <time.h>
#include <dirent.h>
#include <signal.h>
#include <netdb.h>
#include <limits.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/un.h>
#include <arpa/inet.h>
#include "ipc.h"
#include "encoding.h"
#include "curve25519.h"
#include "../uapi.h"
#define SOCK_PATH RUNSTATEDIR "/wireguard/"
@ -42,16 +47,6 @@ struct inflatable_buffer {
#define max(a, b) ((a) > (b) ? (a) : (b))
static int check_version_magic(struct wgdevice *device, int ret)
{
if (ret == -EPROTO || (!ret && device->version_magic != WG_API_VERSION_MAGIC)) {
fprintf(stderr, "This program was built for a different version of WireGuard than\nwhat is currently running. Either this version of wg(8) is out\nof date, or the currently loaded WireGuard module is out of date.\nIf you have just updated your WireGuard installation, you may have\nforgotten to unload the previous running WireGuard module. Try\nrunning `rmmod wireguard` as root, and then try re-adding the interface\nand trying again.\n\n");
errno = EPROTO;
return -EPROTO;
}
return ret;
}
static int add_next_to_inflatable_buffer(struct inflatable_buffer *buffer)
{
size_t len, expand_to;
@ -90,11 +85,12 @@ static int add_next_to_inflatable_buffer(struct inflatable_buffer *buffer)
return 0;
}
static int userspace_interface_fd(const char *interface)
static FILE *userspace_interface_file(const char *interface)
{
struct stat sbuf;
struct sockaddr_un addr = { .sun_family = AF_UNIX };
int fd = -1, ret;
FILE *f;
ret = -EINVAL;
if (strchr(interface, '/'))
@ -119,20 +115,25 @@ static int userspace_interface_fd(const char *interface)
unlink(addr.sun_path);
goto out;
}
f = fdopen(fd, "r+");
if (!f)
ret = -errno;
out:
if (ret && fd >= 0)
close(fd);
if (!ret)
ret = fd;
return ret;
if (ret) {
errno = -ret;
return NULL;
}
return f;
}
static bool userspace_has_wireguard_interface(const char *interface)
{
int fd = userspace_interface_fd(interface);
if (fd < 0)
FILE *f = userspace_interface_file(interface);
if (!f)
return false;
close(fd);
fclose(f);
return true;
}
@ -170,110 +171,261 @@ out:
static int userspace_set_device(struct wgdevice *dev)
{
static const uint8_t zero[WG_KEY_LEN] = { 0 };
char hex[WG_KEY_LEN_HEX], ip[INET6_ADDRSTRLEN], host[4096 + 1], service[512 + 1];
struct wgpeer *peer;
size_t len;
ssize_t ret;
int ret_code;
int fd = userspace_interface_fd(dev->interface);
if (fd < 0)
return fd;
for_each_wgpeer(dev, peer, len);
len = (uint8_t *)peer - (uint8_t *)dev;
ret = -EBADMSG;
if (!len)
goto out;
dev->version_magic = WG_API_VERSION_MAGIC;
ret = write(fd, dev, len);
if (ret < 0)
goto out;
ret = read(fd, &ret_code, sizeof(ret_code));
if (ret < 0)
goto out;
if (ret != sizeof(ret_code)) {
ret = -EBADMSG;
goto out;
struct wgipmask *ipmask;
FILE *f;
int ret;
size_t i, j;
socklen_t addr_len;
f = userspace_interface_file(dev->interface);
if (!f)
return -errno;
fprintf(f, "set=1\n");
if (dev->flags & WGDEVICE_REMOVE_PRIVATE_KEY)
fprintf(f, "private_key=\n");
else if (memcmp(dev->private_key, zero, WG_KEY_LEN)) {
key_to_hex(hex, dev->private_key);
fprintf(f, "private_key=%s\n", hex);
}
ret = ret_code;
out:
close(fd);
if (dev->port)
fprintf(f, "listen_port=%u\n", dev->port);
if (dev->flags & WGDEVICE_REMOVE_FWMARK)
fprintf(f, "fwmark=\n");
else if (dev->fwmark)
fprintf(f, "fwmark=%u\n", dev->fwmark);
if (dev->flags & WGDEVICE_REPLACE_PEERS)
fprintf(f, "replace_peers=true\n");
for_each_wgpeer(dev, peer, i) {
key_to_hex(hex, peer->public_key);
fprintf(f, "public_key=%s\n", hex);
if (peer->flags & WGPEER_REMOVE_ME) {
fprintf(f, "remove=true\n");
continue;
}
if (peer->flags & WGPEER_REMOVE_PRESHARED_KEY)
fprintf(f, "preshared_key=\n");
else if (memcmp(peer->preshared_key, zero, WG_KEY_LEN)) {
key_to_hex(hex, peer->preshared_key);
fprintf(f, "preshared_key=%s\n", hex);
}
if (peer->endpoint.addr.sa_family == AF_INET || peer->endpoint.addr.sa_family == AF_INET6) {
addr_len = 0;
if (peer->endpoint.addr.sa_family == AF_INET)
addr_len = sizeof(struct sockaddr_in);
else if (peer->endpoint.addr.sa_family == AF_INET6)
addr_len = sizeof(struct sockaddr_in6);
if (!getnameinfo(&peer->endpoint.addr, addr_len, host, sizeof(host), service, sizeof(service), NI_DGRAM | NI_NUMERICSERV | NI_NUMERICHOST)) {
if (peer->endpoint.addr.sa_family == AF_INET6 && strchr(host, ':'))
fprintf(f, "endpoint=[%s]:%s\n", host, service);
else
fprintf(f, "endpoint=%s:%s\n", host, service);
}
}
if (peer->persistent_keepalive_interval != (uint16_t)-1)
fprintf(f, "persistent_keepalive_interval=%u\n", peer->persistent_keepalive_interval);
if (peer->flags & WGPEER_REPLACE_IPMASKS)
fprintf(f, "replace_allowed_ips=true\n");
for_each_wgipmask(peer, ipmask, j) {
if (ipmask->family == AF_INET) {
if (!inet_ntop(AF_INET, &ipmask->ip4, ip, INET6_ADDRSTRLEN))
continue;
} else if (ipmask->family == AF_INET6) {
if (!inet_ntop(AF_INET6, &ipmask->ip6, ip, INET6_ADDRSTRLEN))
continue;
} else
continue;
fprintf(f, "allowed_ip=%s/%d\n", ip, ipmask->cidr);
}
}
fprintf(f, "\n");
fflush(f);
if (fscanf(f, "errno=%d\n\n", &ret) != 1)
ret = errno ? -errno : -EPROTO;
fclose(f);
errno = -ret;
return check_version_magic(dev, ret);
return ret;
}
#define READ_BYTES(bytes) ({ \
void *__p; \
size_t __bytes = (bytes); \
if (bytes_left < __bytes) { \
offset = p - buffer; \
bytes_left += buffer_size; \
buffer_size *= 2; \
ret = -ENOMEM; \
p = realloc(buffer, buffer_size); \
if (!p) \
goto out; \
buffer = p; \
p += offset; \
#define ADD(bytes) ({ \
if (buffer_len - buffer_end < bytes) { \
ptrdiff_t peer_offset = (void *)peer - (void *)*out; \
buffer_len = buffer_len * 2 + bytes; \
*out = realloc(*out, buffer_len); \
if (!*out) { \
ret = -errno; \
goto err; \
} \
bytes_left -= __bytes; \
ret = read(fd, p, __bytes); \
if (ret < 0) \
goto out; \
if ((size_t)ret != __bytes) { \
ret = -EBADMSG; \
goto out; \
memset((void *)*out + buffer_end, 0, buffer_len - buffer_end); \
if (peer) \
peer = (void *)*out + peer_offset; \
dev = *out; \
} \
__p = p; \
p += __bytes; \
__p; \
buffer_end += bytes; \
(void *)*out + buffer_end - bytes; \
})
static int userspace_get_device(struct wgdevice **dev, const char *interface)
#define NUM(max) ({ \
unsigned long long num; \
char *end; \
if (!strlen(value)) \
break; \
num = strtoull(value, &end, 10); \
if (*end || num > max) \
break; \
num; \
})
static int userspace_get_device(struct wgdevice **out, const char *interface)
{
unsigned int len = 0, i;
size_t buffer_size, bytes_left;
ssize_t ret;
ptrdiff_t offset;
uint8_t *buffer = NULL, *p, byte = 0;
struct wgdevice *dev;
struct wgpeer *peer = NULL;
size_t buffer_len = 0, buffer_end = 0, line_buffer_len = 0, line_len;
char *key = NULL, *value;
FILE *f;
int ret = -EPROTO;
int fd = userspace_interface_fd(interface);
if (fd < 0)
return fd;
f = userspace_interface_file(interface);
if (!f)
return -errno;
ret = write(fd, &byte, sizeof(byte));
if (ret < 0)
goto out;
if (ret != sizeof(byte)) {
ret = -EBADMSG;
goto out;
fprintf(f, "get=1\n\n");
fflush(f);
*out = NULL;
dev = ADD(sizeof(struct wgdevice));
dev->version_magic = WG_API_VERSION_MAGIC;
strncpy(dev->interface, interface, IFNAMSIZ - 1);
dev->interface[IFNAMSIZ - 1] = '\0';
while (getline(&key, &line_buffer_len, f) > 0) {
line_len = strlen(key);
if (line_len == 1 && key[0] == '\n') {
free(key);
fclose(f);
return ret;
}
value = strchr(key, '=');
if (!value || line_len == 0 || key[line_len - 1] != '\n')
break;
*value++ = key[--line_len] = '\0';
ioctl(fd, FIONREAD, &len);
bytes_left = buffer_size = max(len, sizeof(struct wgdevice) + sizeof(struct wgpeer) + sizeof(struct wgipmask));
p = buffer = malloc(buffer_size);
ret = -ENOMEM;
if (!buffer)
goto out;
len = ((struct wgdevice *)READ_BYTES(sizeof(struct wgdevice)))->num_peers;
ret = check_version_magic((struct wgdevice *)buffer, ret);
if (ret)
goto out;
for (i = 0; i < len; ++i)
READ_BYTES(sizeof(struct wgipmask) * ((struct wgpeer *)READ_BYTES(sizeof(struct wgpeer)))->num_ipmasks);
ret = 0;
out:
if (buffer && ret) {
free(buffer);
buffer = NULL;
if (!strcmp(key, "private_key")) {
if (!key_from_hex(dev->private_key, value))
break;
curve25519_generate_public(dev->public_key, dev->private_key);
} else if (!strcmp(key, "listen_port"))
dev->port = NUM(0xffffU);
else if (!strcmp(key, "fwmark"))
dev->fwmark = NUM(0xffffffffU);
else if (!strcmp(key, "public_key")) {
peer = ADD(sizeof(struct wgpeer));
if (!key_from_hex(peer->public_key, value))
break;
++dev->num_peers;
} else if (peer && !strcmp(key, "preshared_key")) {
if (!key_from_hex(peer->preshared_key, value))
break;
} else if (peer && !strcmp(key, "endpoint")) {
char *begin, *end;
struct addrinfo *resolved;
struct addrinfo hints = {
.ai_family = AF_UNSPEC,
.ai_socktype = SOCK_DGRAM,
.ai_protocol = IPPROTO_UDP
};
if (!strlen(value))
break;
if (value[0] == '[') {
begin = &value[1];
end = strchr(value, ']');
if (!end)
break;
*end++ = '\0';
if (*end++ != ':' || !*end)
break;
} else {
begin = value;
end = strrchr(value, ':');
if (!end || !*(end + 1))
break;
*end++ = '\0';
}
*dev = (struct wgdevice *)buffer;
close(fd);
if (getaddrinfo(begin, end, &hints, &resolved) != 0) {
errno = ENETUNREACH;
goto err;
}
if ((resolved->ai_family == AF_INET && resolved->ai_addrlen == sizeof(struct sockaddr_in)) ||
(resolved->ai_family == AF_INET6 && resolved->ai_addrlen == sizeof(struct sockaddr_in6)))
memcpy(&peer->endpoint.addr, resolved->ai_addr, resolved->ai_addrlen);
else {
freeaddrinfo(resolved);
break;
}
freeaddrinfo(resolved);
} else if (peer && !strcmp(key, "persistent_keepalive_interval"))
peer->persistent_keepalive_interval = NUM(65535U);
else if (peer && !strcmp(key, "allowed_ip")) {
struct wgipmask *ipmask = ADD(sizeof(struct wgipmask));
char *end, *cidr = strchr(value, '/');
if (!cidr || strlen(cidr) <= 1)
break;
*cidr++ = '\0';
ipmask->family = AF_UNSPEC;
if (strchr(value, ':')) {
if (inet_pton(AF_INET6, value, &ipmask->ip6) == 1)
ipmask->family = AF_INET6;
} else {
if (inet_pton(AF_INET, value, &ipmask->ip4) == 1)
ipmask->family = AF_INET;
}
ipmask->cidr = strtoul(cidr, &end, 10);
if (*end || ipmask->family == AF_UNSPEC || (ipmask->family == AF_INET6 && ipmask->cidr > 128) || (ipmask->family == AF_INET && ipmask->cidr > 32))
break;
++peer->num_ipmasks;
} else if (peer && !strcmp(key, "last_handshake_time_sec"))
peer->last_handshake_time.tv_sec = NUM(0xffffffffffffffffULL);
else if (peer && !strcmp(key, "last_handshake_time_nsec"))
peer->last_handshake_time.tv_usec = NUM(0xffffffffffffffffULL) / 1000;
else if (peer && !strcmp(key, "rx_bytes"))
peer->rx_bytes = NUM(0xffffffffffffffffULL);
else if (peer && !strcmp(key, "tx_bytes"))
peer->tx_bytes = NUM(0xffffffffffffffffULL);
else if (!strcmp(key, "errno"))
ret = -NUM(0x7fffffffU);
else
break;
}
ret = -EPROTO;
err:
free(key);
free(*out);
*out = NULL;
fclose(f);
errno = -ret;
return ret;
}
#undef READ_BYTES
#undef ADD
#undef NUM
#undef KEY
#ifdef __linux__
static int check_version_magic(struct wgdevice *device, int ret)
{
if (ret == -EPROTO || (!ret && device->version_magic != WG_API_VERSION_MAGIC)) {
fprintf(stderr, "This program was built for a different version of WireGuard than\nwhat is currently running. Either this version of wg(8) is out\nof date, or the currently loaded WireGuard module is out of date.\nIf you have just updated your WireGuard installation, you may have\nforgotten to unload the previous running WireGuard module. Try\nrunning `rmmod wireguard` as root, and then try re-adding the interface\nand trying again.\n\n");
errno = EPROTO;
return -EPROTO;
}
return ret;
}
static int parse_linkinfo(const struct nlattr *attr, void *data)
{
struct inflatable_buffer *buffer = data;
@ -295,9 +447,11 @@ static int parse_infomsg(const struct nlattr *attr, void *data)
static int read_devices_cb(const struct nlmsghdr *nlh, void *data)
{
struct inflatable_buffer *buffer = data;
int ret;
buffer->good = false;
buffer->next = NULL;
int ret = mnl_attr_parse(nlh, sizeof(struct ifinfomsg), parse_infomsg, data);
ret = mnl_attr_parse(nlh, sizeof(struct ifinfomsg), parse_infomsg, data);
if (ret != MNL_CB_OK)
return ret;
ret = add_next_to_inflatable_buffer(buffer);

View File

@ -5,7 +5,7 @@
#include <ctype.h>
#include "curve25519.h"
#include "base64.h"
#include "encoding.h"
#include "subcommands.h"
int pubkey_main(int argc, char *argv[])

View File

@ -16,7 +16,7 @@
#include "ipc.h"
#include "subcommands.h"
#include "terminal.h"
#include "base64.h"
#include "encoding.h"
#include "../uapi.h"
static int peer_cmp(const void *first, const void *second)

View File

@ -10,7 +10,7 @@
#include <netdb.h>
#include "subcommands.h"
#include "base64.h"
#include "encoding.h"
#include "ipc.h"
#include "../uapi.h"
@ -79,16 +79,16 @@ int showconf_main(int argc, char *argv[])
if (peer->endpoint.addr.sa_family == AF_INET || peer->endpoint.addr.sa_family == AF_INET6) {
char host[4096 + 1];
char service[512 + 1];
static char buf[sizeof(host) + sizeof(service) + 4];
socklen_t addr_len = 0;
memset(buf, 0, sizeof(buf));
if (peer->endpoint.addr.sa_family == AF_INET)
addr_len = sizeof(struct sockaddr_in);
else if (peer->endpoint.addr.sa_family == AF_INET6)
addr_len = sizeof(struct sockaddr_in6);
if (!getnameinfo(&peer->endpoint.addr, addr_len, host, sizeof(host), service, sizeof(service), NI_DGRAM | NI_NUMERICSERV | NI_NUMERICHOST)) {
snprintf(buf, sizeof(buf) - 1, (peer->endpoint.addr.sa_family == AF_INET6 && strchr(host, ':')) ? "[%s]:%s" : "%s:%s", host, service);
printf("Endpoint = %s\n", buf);
if (peer->endpoint.addr.sa_family == AF_INET6 && strchr(host, ':'))
printf("Endpoint = [%s]:%s\n", host, service);
else
printf("Endpoint = %s:%s\n", host, service);
}
}