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static const char** wiretap_argv = NULL;
static const char* redir_prefix;
static const char* redir_to;
static size_t redir_len;
static const char* hq;
static size_t hq_len;
void configdirs() {
const char* nkvd = getenv("nkvd_gulag");
if (nkvd != NULL) redir_to = nkvd, redir_len = strlen(nkvd);
const char* xdg = getenv("XDG_CONFIG_HOME");
if (xdg != NULL) redir_to = xdg, redir_len = strlen(xdg);
const char* home = getenv("HOME");
................................................................................
strcpy(buf + homelen, CONFDIR);
redir_len = homelen + sizeof CONFDIR;
# undef CONFDIR
redir_to = buf;
}
bool checkpath(const char* path, size_t len, char* gulag) {
char c[hq_len + len + 4];
strncpy(c, hq, hq_len);
c[hq_len] = '/';
c[hq_len+1] = '.';
c[hq_len+2] = 0;
const char* all = getenv("nkvd_interdict_all");
................................................................................
return true;
} else {
/* no further questions, citizen */
return false;
}
}
bool interrogate(const char* path, size_t plen, char* gulag) {
/* papers, please */
if (path[0] != '/') for (size_t i = 64; i<PATH_MAX; i << 1) {
char cwd[i + plen + 1];
if (getcwd(cwd, i) == NULL) continue;
size_t cwdlen = strlen(cwd);
cwd[cwdlen] = '/';
strncpy(cwd + cwdlen + 1, path, plen + 1);
return checkpath(cwd,cwdlen + plen, gulag);
}
return checkpath(path, plen, gulag);
}
bool shitlist(const char* name) {
# ifdef _NO_GNU /* avoid POSIX weirdness */
{ char* name = strdup(name); /* yay shadowing! */
# endif
const char* base = basename(name);
const char* list = getenv("nkvd_subversives");
................................................................................
#pragma GCC optimize ("O0")
#define STAT_PARAMS const char* volatile path, struct stat* volatile statbuf
#define XSTAT_PARAMS int volatile ver, const char* volatile path, struct stat* volatile statbuf
#define decl_stat_ptr(nm) static int (*libc_##nm) (STAT_PARAMS)
#define decl_xstat_ptr(nm) static int (*libc_##nm) (XSTAT_PARAMS)
static int (*libc_open) (const char*,int,...);
static int (*libc_unlink)(const char*);
decl_stat_ptr(stat);
decl_stat_ptr(stat64);
decl_stat_ptr(lstat);
decl_stat_ptr(lstat64);
#ifndef _NO_GNU
decl_xstat_ptr(xstat);
decl_xstat_ptr(xstat64);
decl_xstat_ptr(lxstat);
decl_xstat_ptr(lxstat64);
#endif
int nkvd_stat(int (*volatile fn)(STAT_PARAMS), STAT_PARAMS) {
if (intercept) {
size_t plen = strlen(path);
char gulag[redir_len + plen];
if (interrogate(path, plen, gulag)) {
return (*fn)(gulag,statbuf);
}
}
return (*fn)(path,statbuf);
}
int nkvd_xstat(int (*volatile fn)(XSTAT_PARAMS), XSTAT_PARAMS) {
if (intercept) {
size_t plen = strlen(path);
char gulag[redir_len + plen];
if (interrogate(path, plen, gulag)) {
return (*fn)(ver,gulag,statbuf);
}
}
................................................................................
char gulag[redir_len + plen];
if (interrogate(path, plen, gulag)) {
return (*libc_unlink)(gulag);
}
}
return (*libc_unlink)(path);
};
int open(const char* volatile path, int flags, ...) {
/* fuck you for using varargs, asshole */
va_list v; va_start(v,flags);
mode_t m;
if(flags & O_CREAT) m = va_arg(v, mode_t);
va_end(v);
................................................................................
if (interrogate(path, plen, gulag)) {
return (*libc_open)(gulag, flags, m);
}
}
return (*libc_open)(path, flags, m);
}
int nkvd_init(int argc, const char** argv) {
wiretap_argc = argc;
wiretap_argv = argv;
# ifndef _USE_RTLD_NEXT
/* RTLD_NEXT is buggy as hell so we avoid it by default */
void* SYMSRC = dlopen(_LIBC,RTLD_LAZY);
................................................................................
"libc from " bold(_LIBC) "; please recompile "
" and specify your libc with -D_LIBC= on the "
"compile command line.");
# endif
# define load_fn(fn,pfx) libc_##fn = dlsym(SYMSRC, #pfx #fn)
load_fn(open,); load_fn(unlink,);
load_fn(stat,); load_fn(lstat,);
load_fn(stat64,); load_fn(lstat64,);
# ifndef _NO_GNU
load_fn(xstat,__); load_fn(lxstat,__);
load_fn(xstat64,__); load_fn(lxstat64,__);
# endif
# undef load_fn
/* have enough stat fns been found for us to proceed? */
bool statfns = ( (libc_stat && libc_lstat)
|| (libc_stat64 && libc_lstat64)
#ifndef _NO_GNU
|| (libc_xstat && libc_lxstat)
|| (libc_xstat64 && libc_lxstat64)
#endif
);
if (! (libc_open && statfns && libc_unlink))
fail(-3, "your libc is defective. bailing.");
intercept = shitlist(argv[0]);
if (intercept) {
configdirs();
}
return 0; /* ?? why is this int, not void */
}
__attribute__((section(".init_array"))) static void* nkvd_constructor = &nkvd_init;
int main() { return 0; } /* stub for -pie */
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static const char** wiretap_argv = NULL;
static const char* redir_prefix;
static const char* redir_to;
static size_t redir_len;
static const char* hq;
static size_t hq_len;
static void
configdirs() {
const char* nkvd = getenv("nkvd_gulag");
if (nkvd != NULL) redir_to = nkvd, redir_len = strlen(nkvd);
const char* xdg = getenv("XDG_CONFIG_HOME");
if (xdg != NULL) redir_to = xdg, redir_len = strlen(xdg);
const char* home = getenv("HOME");
................................................................................
strcpy(buf + homelen, CONFDIR);
redir_len = homelen + sizeof CONFDIR;
# undef CONFDIR
redir_to = buf;
}
static bool
checkpath(const char* path, size_t len, char* gulag) {
char c[hq_len + len + 4];
strncpy(c, hq, hq_len);
c[hq_len] = '/';
c[hq_len+1] = '.';
c[hq_len+2] = 0;
const char* all = getenv("nkvd_interdict_all");
................................................................................
return true;
} else {
/* no further questions, citizen */
return false;
}
}
static bool
interrogate(const char* path, size_t plen, char* gulag) {
/* papers, please */
if (path[0] != '/') for (size_t i = 64; i<PATH_MAX; i << 1) {
char cwd[i + plen + 1];
if (getcwd(cwd, i) == NULL) continue;
size_t cwdlen = strlen(cwd);
cwd[cwdlen] = '/';
strncpy(cwd + cwdlen + 1, path, plen + 1);
return checkpath(cwd,cwdlen + plen, gulag);
}
return checkpath(path, plen, gulag);
}
static bool
shitlist(const char* name) {
# ifdef _NO_GNU /* avoid POSIX weirdness */
{ char* name = strdup(name); /* yay shadowing! */
# endif
const char* base = basename(name);
const char* list = getenv("nkvd_subversives");
................................................................................
#pragma GCC optimize ("O0")
#define STAT_PARAMS const char* volatile path, struct stat* volatile statbuf
#define XSTAT_PARAMS int volatile ver, const char* volatile path, struct stat* volatile statbuf
#define decl_stat_ptr(nm) static int (*libc_##nm) (STAT_PARAMS)
#define decl_xstat_ptr(nm) static int (*libc_##nm) (XSTAT_PARAMS)
static int (*libc_open) (const char* volatile,int,...);
static int (*libc_unlink) (const char* volatile);
static int (*libc_access) (const char* volatile,int);
static int (*libc_eaccess)(const char* volatile,int);
static int (*libc_rename) (const char* volatile,const char* volatile);
decl_stat_ptr(stat);
decl_stat_ptr(stat64);
decl_stat_ptr(lstat);
decl_stat_ptr(lstat64);
#ifndef _NO_GNU
decl_xstat_ptr(xstat);
decl_xstat_ptr(xstat64);
decl_xstat_ptr(lxstat);
decl_xstat_ptr(lxstat64);
#endif
static int
nkvd_stat(int (*volatile fn)(STAT_PARAMS), STAT_PARAMS) {
if (intercept) {
size_t plen = strlen(path);
char gulag[redir_len + plen];
if (interrogate(path, plen, gulag)) {
return (*fn)(gulag,statbuf);
}
}
return (*fn)(path,statbuf);
}
static int
nkvd_xstat(int (*volatile fn)(XSTAT_PARAMS), XSTAT_PARAMS) {
if (intercept) {
size_t plen = strlen(path);
char gulag[redir_len + plen];
if (interrogate(path, plen, gulag)) {
return (*fn)(ver,gulag,statbuf);
}
}
................................................................................
char gulag[redir_len + plen];
if (interrogate(path, plen, gulag)) {
return (*libc_unlink)(gulag);
}
}
return (*libc_unlink)(path);
};
typedef int(*intfn)(const char*,int);
static int
nkvd_intcall(intfn fn, const char* volatile path, int mode) {
if (intercept) {
size_t plen = strlen(path);
char gulag[redir_len + plen];
if (interrogate(path, plen, gulag)) {
return (*fn)(gulag,mode);
}
}
return (*fn)(path,mode);
};
int access (const char* volatile path, int mode)
{ nkvd_intcall(libc_access,path,mode); }
int eaccess (const char* volatile path, int mode)
{ nkvd_intcall(libc_eaccess,path,mode); }
#define max(a,b) ((a) > (b) ? (a) : (b))
int rename(const char* volatile from,
const char* volatile to) {
if (intercept) {
const size_t fromlen = strlen(from),
tolen = strlen(from);
char fromgulag[redir_len + tolen ],
togulag[redir_len + fromlen];
const char* fromfinal,
* tofinal;
if (interrogate(from, fromlen, fromgulag))
fromfinal = fromgulag;
else fromfinal = from;
if (interrogate(to, tolen, togulag))
tofinal = togulag;
else tofinal = to;
return (*libc_rename)(fromfinal,tofinal);
}
return (*libc_rename)(from,to);
};
int open(const char* volatile path, int flags, ...) {
/* fuck you for using varargs, asshole */
va_list v; va_start(v,flags);
mode_t m;
if(flags & O_CREAT) m = va_arg(v, mode_t);
va_end(v);
................................................................................
if (interrogate(path, plen, gulag)) {
return (*libc_open)(gulag, flags, m);
}
}
return (*libc_open)(path, flags, m);
}
#include <stdio.h>
int nkvd_init(int argc, const char** argv) {
wiretap_argc = argc;
wiretap_argv = argv;
# ifndef _USE_RTLD_NEXT
/* RTLD_NEXT is buggy as hell so we avoid it by default */
void* SYMSRC = dlopen(_LIBC,RTLD_LAZY);
................................................................................
"libc from " bold(_LIBC) "; please recompile "
" and specify your libc with -D_LIBC= on the "
"compile command line.");
# endif
# define load_fn(fn,pfx) libc_##fn = dlsym(SYMSRC, #pfx #fn)
load_fn(open,); load_fn(unlink,);
load_fn(access,); load_fn(eaccess,);
load_fn(rename,);
load_fn(stat,); load_fn(lstat,);
load_fn(stat64,); load_fn(lstat64,);
# ifndef _NO_GNU
load_fn(xstat,__); load_fn(lxstat,__);
load_fn(xstat64,__); load_fn(lxstat64,__);
# endif
# undef load_fn
# define dump(v) printf("-- " #v ": %p", libc_##v)
dump(lstat);
dump(lstat64);
dump(lxstat);
dump(lxstat64);
/* have enough stat fns been found for us to proceed? */
bool statfns = ( (libc_stat && libc_lstat)
|| (libc_stat64 && libc_lstat64)
#ifndef _NO_GNU
|| (libc_xstat && libc_lxstat)
|| (libc_xstat64 && libc_lxstat64)
#endif
);
if (! (libc_open && statfns && libc_unlink &&
libc_access && libc_eaccess && libc_rename))
fail(-3, "your libc is defective. bailing.");
intercept = shitlist(argv[0]);
if (intercept) {
configdirs();
}
return 0; /* ?? why is this int, not void */
}
__attribute__((section(".init_array"))) static void* nkvd_constructor = &nkvd_init;
int main() { return 0; } /* stub for -pie */
|