wg-quick: android: support excluding applications

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
This commit is contained in:
Jason A. Donenfeld 2018-07-05 19:26:13 +02:00
parent b3b6d97db8
commit 4367cd0d3d
1 changed files with 102 additions and 9 deletions

View File

@ -34,6 +34,15 @@
static bool is_exiting = false; static bool is_exiting = false;
/* TODO: remove this once the NDK supports it. */
static char *strchrnul(const char *s, int c)
{
char *x = strchr(s, c);
if (!x)
return (char *)s + strlen(s);
return x;
}
static void *xmalloc(size_t size) static void *xmalloc(size_t size)
{ {
void *ret = malloc(size); void *ret = malloc(size);
@ -43,6 +52,15 @@ static void *xmalloc(size_t size)
exit(errno); exit(errno);
} }
static void *xcalloc(size_t nmemb, size_t size)
{
void *ret = calloc(nmemb, size);
if (ret)
return ret;
perror("Error: calloc");
exit(errno);
}
static void *xstrdup(const char *str) static void *xstrdup(const char *str)
{ {
char *ret = strdup(str); char *ret = strdup(str);
@ -288,9 +306,79 @@ static void up_if(unsigned int *netid, const char *iface)
cndc("network interface add %u %s", *netid, iface); cndc("network interface add %u %s", *netid, iface);
} }
static void set_users(unsigned int netid) static int compare_uid(const void *a, const void *b)
{ {
cndc("network users add %u 0-99999", netid); return *(const uid_t *)a - *(const uid_t *)b;
}
static uid_t *get_uid_list(const char *selected_applications)
{
_cleanup_fclose_ FILE *package_list = NULL;
_cleanup_free_ char *line = NULL;
uid_t package_uid;
size_t line_len = 0, i;
const char *comma, *start;
uid_t *uid_list;
if (!selected_applications)
return xcalloc(1, sizeof(*uid_list));
for (i = 1, comma = selected_applications; comma; comma = strchr(comma + 1, ','), ++i);
uid_list = xcalloc(i, sizeof(*uid_list));
i = 0;
package_list = fopen("/data/system/packages.list", "r");
if (!package_list) {
perror("Error: Unable to open package list");
exit(errno);
}
while (getline(&line, &line_len, package_list) >= 0) {
char *package_name, *package_uid_str, *endptr;
package_name = line;
package_uid_str = strchr(package_name, ' ');
if (!package_uid_str)
continue;
*package_uid_str++ = '\0';
*strchrnul(package_uid_str, ' ') = '\0';
package_uid = strtoul(package_uid_str, &endptr, 10);
if (!package_uid || !*package_uid_str || *endptr)
continue;
for (start = selected_applications; comma = strchrnul(start, ','), *start; start = comma + 1) {
ptrdiff_t token_len = comma - start;
if (token_len && strlen(package_name) == token_len && !strncmp(start, package_name, token_len))
uid_list[i++] = package_uid;
}
}
qsort(uid_list, i, sizeof(*uid_list), compare_uid);
return uid_list;
}
static void set_users(unsigned int netid, const char *excluded_applications)
{
_cleanup_free_ uid_t *excluded_uids = get_uid_list(excluded_applications);
_cleanup_free_ char *ranges = NULL;
char range[22];
uid_t start;
for (start = 0; *excluded_uids; start = *excluded_uids + 1, ++excluded_uids) {
if (start > *excluded_uids - 1)
continue;
else if (start == *excluded_uids - 1)
snprintf(range, sizeof(range), "%u", start);
else
snprintf(range, sizeof(range), "%u-%u", start, *excluded_uids - 1);
ranges = concat_and_free(ranges, " ", range);
}
if (start < 99999) {
snprintf(range, sizeof(range), "%u-99999", start);
ranges = concat_and_free(ranges, " ", range);
}
cndc("network users add %u %s", netid, ranges);
} }
static void set_dnses(unsigned int netid, const char *dnses) static void set_dnses(unsigned int netid, const char *dnses)
@ -536,7 +624,8 @@ static void cmd_usage(const char *program)
" - Address: may be specified one or more times and contains one or more\n" " - Address: may be specified one or more times and contains one or more\n"
" IP addresses (with an optional CIDR mask) to be set for the interface.\n" " IP addresses (with an optional CIDR mask) to be set for the interface.\n"
" - MTU: an optional MTU for the interface; if unspecified, auto-calculated.\n" " - MTU: an optional MTU for the interface; if unspecified, auto-calculated.\n"
" - DNS: an optional DNS server to use while the device is up.\n\n" " - DNS: an optional DNS server to use while the device is up.\n"
" - ExcludedApplications: optional applications to exclude from the tunnel.\n\n"
" See wg-quick(8) for more info and examples.\n"); " See wg-quick(8) for more info and examples.\n");
} }
@ -550,7 +639,7 @@ static void cmd_up_cleanup(void)
free(cleanup_iface); free(cleanup_iface);
} }
static void cmd_up(const char *iface, const char *config, unsigned int mtu, const char *addrs, const char *dnses) static void cmd_up(const char *iface, const char *config, unsigned int mtu, const char *addrs, const char *dnses, const char *excluded_applications)
{ {
DEFINE_CMD(c); DEFINE_CMD(c);
unsigned int netid = 0; unsigned int netid = 0;
@ -571,7 +660,7 @@ static void cmd_up(const char *iface, const char *config, unsigned int mtu, cons
set_dnses(netid, dnses); set_dnses(netid, dnses);
set_routes(iface, netid); set_routes(iface, netid);
set_mtu(iface, mtu); set_mtu(iface, mtu);
set_users(netid); set_users(netid, excluded_applications);
broadcast_change(); broadcast_change();
free(cleanup_iface); free(cleanup_iface);
@ -604,7 +693,7 @@ static void cmd_down(const char *iface)
exit(EXIT_SUCCESS); exit(EXIT_SUCCESS);
} }
static void parse_options(char **iface, char **config, unsigned int *mtu, char **addrs, char **dnses, const char *arg) static void parse_options(char **iface, char **config, unsigned int *mtu, char **addrs, char **dnses, char **excluded_applications, const char *arg)
{ {
_cleanup_fclose_ FILE *file = NULL; _cleanup_fclose_ FILE *file = NULL;
_cleanup_free_ char *line = NULL; _cleanup_free_ char *line = NULL;
@ -685,6 +774,9 @@ static void parse_options(char **iface, char **config, unsigned int *mtu, char *
} else if (!strncasecmp(clean, "DNS=", 4) && j > 4) { } else if (!strncasecmp(clean, "DNS=", 4) && j > 4) {
*dnses = concat_and_free(*dnses, ",", clean + 4); *dnses = concat_and_free(*dnses, ",", clean + 4);
continue; continue;
} else if (!strncasecmp(clean, "ExcludedApplications=", 21) && j > 4) {
*excluded_applications = concat_and_free(*excluded_applications, ",", clean + 21);
continue;
} else if (!strncasecmp(clean, "MTU=", 4) && j > 4) { } else if (!strncasecmp(clean, "MTU=", 4) && j > 4) {
*mtu = atoi(clean + 4); *mtu = atoi(clean + 4);
continue; continue;
@ -709,17 +801,18 @@ int main(int argc, char *argv[])
_cleanup_free_ char *config = NULL; _cleanup_free_ char *config = NULL;
_cleanup_free_ char *addrs = NULL; _cleanup_free_ char *addrs = NULL;
_cleanup_free_ char *dnses = NULL; _cleanup_free_ char *dnses = NULL;
_cleanup_free_ char *excluded_applications = NULL;
unsigned int mtu; unsigned int mtu;
if (argc == 2 && (!strcmp(argv[1], "help") || !strcmp(argv[1], "--help") || !strcmp(argv[1], "-h"))) if (argc == 2 && (!strcmp(argv[1], "help") || !strcmp(argv[1], "--help") || !strcmp(argv[1], "-h")))
cmd_usage(argv[0]); cmd_usage(argv[0]);
else if (argc == 3 && !strcmp(argv[1], "up")) { else if (argc == 3 && !strcmp(argv[1], "up")) {
auto_su(argc, argv); auto_su(argc, argv);
parse_options(&iface, &config, &mtu, &addrs, &dnses, argv[2]); parse_options(&iface, &config, &mtu, &addrs, &dnses, &excluded_applications, argv[2]);
cmd_up(iface, config, mtu, addrs, dnses); cmd_up(iface, config, mtu, addrs, dnses, excluded_applications);
} else if (argc == 3 && !strcmp(argv[1], "down")) { } else if (argc == 3 && !strcmp(argv[1], "down")) {
auto_su(argc, argv); auto_su(argc, argv);
parse_options(&iface, &config, &mtu, &addrs, &dnses, argv[2]); parse_options(&iface, &config, &mtu, &addrs, &dnses, &excluded_applications, argv[2]);
cmd_down(iface); cmd_down(iface);
} else { } else {
cmd_usage(argv[0]); cmd_usage(argv[0]);