Add hook to close_range function, solves #439. |0!

pull/443/head
Recolic Keghart 8 months ago
parent 07c15a02f6
commit 0000000062
  1. 1
      .gitignore
  2. 1
      src/core.h
  3. 84
      src/libproxychains.c

1
.gitignore vendored

@ -1,4 +1,5 @@
proxychains4
proxychains4-daemon
*.bz2
*.xz
*.o

@ -100,6 +100,7 @@ int connect_proxy_chain (int sock, ip_type target_ip, unsigned short target_port
void proxychains_write_log(char *str, ...);
typedef int (*close_t)(int);
typedef int (*close_range_t)(unsigned, unsigned, int);
typedef int (*connect_t)(int, const struct sockaddr *, socklen_t);
typedef struct hostent* (*gethostbyname_t)(const char *);
typedef int (*freeaddrinfo_t)(struct addrinfo *);

@ -56,6 +56,7 @@ connect_t true___xnet_connect;
#endif
close_t true_close;
close_range_t true_close_range;
connect_t true_connect;
gethostbyname_t true_gethostbyname;
getaddrinfo_t true_getaddrinfo;
@ -86,13 +87,14 @@ static int init_l = 0;
static void get_chain_data(proxy_data * pd, unsigned int *proxy_count, chain_type * ct);
static void* load_sym(char* symname, void* proxyfunc) {
static void* load_sym(char* symname, void* proxyfunc, int is_mandatory) {
void *funcptr = dlsym(RTLD_NEXT, symname);
if(!funcptr) {
if(is_mandatory && !funcptr) {
fprintf(stderr, "Cannot load symbol '%s' %s\n", symname, dlerror());
exit(1);
} else if (!funcptr) {
return funcptr;
} else {
PDEBUG("loaded symbol '%s'" " real addr %p wrapped addr %p\n", symname, funcptr, proxyfunc);
}
@ -112,8 +114,16 @@ const char *proxychains_get_version(void);
static void setup_hooks(void);
typedef struct {
unsigned int first, last, flags;
} close_range_args_t;
/* If there is some `close` or `close_range` system call before do_init,
we buffer it, and actually execute them in do_init. */
static int close_fds[16];
static int close_fds_cnt = 0;
static close_range_args_t close_range_buffer[16];
static int close_range_buffer_cnt = 0;
static unsigned get_rand_seed(void) {
#ifdef HAVE_CLOCK_GETTIME
@ -138,6 +148,10 @@ static void do_init(void) {
setup_hooks();
while(close_fds_cnt) true_close(close_fds[--close_fds_cnt]);
while(close_range_buffer_cnt) {
int i = --close_range_buffer_cnt;
true_close_range(close_range_buffer[i].first, close_range_buffer[i].last, close_range_buffer[i].flags);
}
init_l = 1;
rdns_init(proxychains_resolver);
@ -587,6 +601,64 @@ static int is_v4inv6(const struct in6_addr *a) {
return !memcmp(a->s6_addr, "\0\0\0\0\0\0\0\0\0\0\xff\xff", 12);
}
static int compare_func_int(const void *l, const void *r) {
int arg1 = *(const int*)l;
int arg2 = *(const int*)r;
return (arg1 > arg2) - (arg1 < arg2);
}
/* Warning: Linux manual says the third arg is `unsigned int`, but unistd.h says `int`. */
HOOKFUNC(int, close_range, unsigned first, unsigned last, int flags) {
if(true_close_range == NULL) {
fprintf(stderr, "Calling close_range, but this platform does not provide this system call. ");
return -1;
}
if(!init_l) {
/* push back to cache, and delay the execution. */
if(close_range_buffer_cnt >= (sizeof close_range_buffer / sizeof close_range_buffer[0])) {
errno = ENOMEM;
return -1;
}
int i = close_range_buffer_cnt++;
close_range_buffer[i].first = first;
close_range_buffer[i].last = last;
close_range_buffer[i].flags = flags;
return errno = 0;
}
if(proxychains_resolver != DNSLF_RDNS_THREAD) return true_close_range(first, last, flags);
/* prevent rude programs (like ssh) from closing our pipes */
int res = 0, uerrno = 0, i;
int protected_fds[] = {req_pipefd[0], req_pipefd[1], resp_pipefd[0], resp_pipefd[1]};
int protected_fds_size = sizeof protected_fds / sizeof protected_fds[0];
qsort(protected_fds, protected_fds_size, sizeof protected_fds[0], compare_func_int);
/* We are skipping protected_fds while calling true_close_range()
* If protected_fds cut the range into some sub-ranges, we close sub-ranges BEFORE cut point in the loop.
* [first, cut1-1] , [cut1+1, cut2-1] , [cut2+1, cut3-1]
* Finally, we delete the remaining sub-range, outside the loop. [cut3+1, tail]
*/
int next_fd_to_close = first;
for(i = 0; i < protected_fds_size; ++i) {
if(protected_fds[i] < first || protected_fds[i] > last)
continue;
int prev = (i == 0 || protected_fds[i-1] < first) ? first : protected_fds[i-1]+1;
if(prev != protected_fds[i]) {
if(-1 == true_close_range(prev, protected_fds[i]-1, flags)) {
res = -1;
uerrno = errno;
}
}
next_fd_to_close = protected_fds[i]+1;
}
if(next_fd_to_close <= last) {
if(-1 == true_close_range(next_fd_to_close, last, flags)) {
res = -1;
uerrno = errno;
}
}
errno = uerrno;
return res;
}
HOOKFUNC(int, connect, int sock, const struct sockaddr *addr, unsigned int len) {
INIT();
PFUNC();
@ -825,8 +897,11 @@ HOOKFUNC(ssize_t, sendto, int sockfd, const void *buf, size_t len, int flags,
#ifdef MONTEREY_HOOKING
#define SETUP_SYM(X) do { if (! true_ ## X ) true_ ## X = &X; } while(0)
#define SETUP_SYM_OPTIONAL(X)
#else
#define SETUP_SYM(X) do { if (! true_ ## X ) true_ ## X = load_sym( # X, X ); } while(0)
#define SETUP_SYM_IMPL(X, IS_MANDATORY) do { if (! true_ ## X ) true_ ## X = load_sym( # X, X, IS_MANDATORY ); } while(0)
#define SETUP_SYM(X) SETUP_SYM_IMPL(X, 1)
#define SETUP_SYM_OPTIONAL(X) SETUP_SYM_IMPL(X, 0)
#endif
static void setup_hooks(void) {
@ -841,6 +916,7 @@ static void setup_hooks(void) {
SETUP_SYM(__xnet_connect);
#endif
SETUP_SYM(close);
SETUP_SYM_OPTIONAL(close_range);
}
#ifdef MONTEREY_HOOKING

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