mirror of
https://github.com/git/git
synced 2024-08-25 02:35:46 +00:00
![Linus Torvalds](/assets/img/avatar_default.png)
This adds a very git specific restricted shell, that can be added to /etc/shells and set to the pw_shell in the /etc/passwd file, to give users ability to push into repositories over ssh without giving them full interactive shell acount. [jc: I updated Linus' patch to match what the current sq_quote() does.] Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
258 lines
5.3 KiB
C
258 lines
5.3 KiB
C
#include "cache.h"
|
|
#include "quote.h"
|
|
|
|
/* Help to copy the thing properly quoted for the shell safety.
|
|
* any single quote is replaced with '\'', any exclamation point
|
|
* is replaced with '\!', and the whole thing is enclosed in a
|
|
*
|
|
* E.g.
|
|
* original sq_quote result
|
|
* name ==> name ==> 'name'
|
|
* a b ==> a b ==> 'a b'
|
|
* a'b ==> a'\''b ==> 'a'\''b'
|
|
* a!b ==> a'\!'b ==> 'a'\!'b'
|
|
*/
|
|
#undef EMIT
|
|
#define EMIT(x) ( (++len < n) && (*bp++ = (x)) )
|
|
|
|
static inline int need_bs_quote(char c)
|
|
{
|
|
return (c == '\'' || c == '!');
|
|
}
|
|
|
|
size_t sq_quote_buf(char *dst, size_t n, const char *src)
|
|
{
|
|
char c;
|
|
char *bp = dst;
|
|
size_t len = 0;
|
|
|
|
EMIT('\'');
|
|
while ((c = *src++)) {
|
|
if (need_bs_quote(c)) {
|
|
EMIT('\'');
|
|
EMIT('\\');
|
|
EMIT(c);
|
|
EMIT('\'');
|
|
} else {
|
|
EMIT(c);
|
|
}
|
|
}
|
|
EMIT('\'');
|
|
|
|
if ( n )
|
|
*bp = 0;
|
|
|
|
return len;
|
|
}
|
|
|
|
char *sq_quote(const char *src)
|
|
{
|
|
char *buf;
|
|
size_t cnt;
|
|
|
|
cnt = sq_quote_buf(NULL, 0, src) + 1;
|
|
buf = xmalloc(cnt);
|
|
sq_quote_buf(buf, cnt, src);
|
|
|
|
return buf;
|
|
}
|
|
|
|
char *sq_dequote(char *arg)
|
|
{
|
|
char *dst = arg;
|
|
char *src = arg;
|
|
char c;
|
|
|
|
if (*src != '\'')
|
|
return NULL;
|
|
for (;;) {
|
|
c = *++src;
|
|
if (!c)
|
|
return NULL;
|
|
if (c != '\'') {
|
|
*dst++ = c;
|
|
continue;
|
|
}
|
|
/* We stepped out of sq */
|
|
switch (*++src) {
|
|
case '\0':
|
|
*dst = 0;
|
|
return arg;
|
|
case '\\':
|
|
c = *++src;
|
|
if (need_bs_quote(c) && *++src == '\'') {
|
|
*dst++ = c;
|
|
continue;
|
|
}
|
|
/* Fallthrough */
|
|
default:
|
|
return NULL;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* C-style name quoting.
|
|
*
|
|
* Does one of three things:
|
|
*
|
|
* (1) if outbuf and outfp are both NULL, inspect the input name and
|
|
* counts the number of bytes that are needed to hold c_style
|
|
* quoted version of name, counting the double quotes around
|
|
* it but not terminating NUL, and returns it. However, if name
|
|
* does not need c_style quoting, it returns 0.
|
|
*
|
|
* (2) if outbuf is not NULL, it must point at a buffer large enough
|
|
* to hold the c_style quoted version of name, enclosing double
|
|
* quotes, and terminating NUL. Fills outbuf with c_style quoted
|
|
* version of name enclosed in double-quote pair. Return value
|
|
* is undefined.
|
|
*
|
|
* (3) if outfp is not NULL, outputs c_style quoted version of name,
|
|
* but not enclosed in double-quote pair. Return value is undefined.
|
|
*/
|
|
|
|
int quote_c_style(const char *name, char *outbuf, FILE *outfp, int no_dq)
|
|
{
|
|
#undef EMIT
|
|
#define EMIT(c) \
|
|
(outbuf ? (*outbuf++ = (c)) : outfp ? fputc(c, outfp) : (count++))
|
|
|
|
#define EMITQ() EMIT('\\')
|
|
|
|
const char *sp;
|
|
int ch, count = 0, needquote = 0;
|
|
|
|
if (!no_dq)
|
|
EMIT('"');
|
|
for (sp = name; (ch = *sp++); ) {
|
|
|
|
if ((ch < ' ') || (ch == '"') || (ch == '\\') ||
|
|
(ch == 0177)) {
|
|
needquote = 1;
|
|
switch (ch) {
|
|
case '\a': EMITQ(); ch = 'a'; break;
|
|
case '\b': EMITQ(); ch = 'b'; break;
|
|
case '\f': EMITQ(); ch = 'f'; break;
|
|
case '\n': EMITQ(); ch = 'n'; break;
|
|
case '\r': EMITQ(); ch = 'r'; break;
|
|
case '\t': EMITQ(); ch = 't'; break;
|
|
case '\v': EMITQ(); ch = 'v'; break;
|
|
|
|
case '\\': /* fallthru */
|
|
case '"': EMITQ(); break;
|
|
case ' ':
|
|
break;
|
|
default:
|
|
/* octal */
|
|
EMITQ();
|
|
EMIT(((ch >> 6) & 03) + '0');
|
|
EMIT(((ch >> 3) & 07) + '0');
|
|
ch = (ch & 07) + '0';
|
|
break;
|
|
}
|
|
}
|
|
EMIT(ch);
|
|
}
|
|
if (!no_dq)
|
|
EMIT('"');
|
|
if (outbuf)
|
|
*outbuf = 0;
|
|
|
|
return needquote ? count : 0;
|
|
}
|
|
|
|
/*
|
|
* C-style name unquoting.
|
|
*
|
|
* Quoted should point at the opening double quote. Returns
|
|
* an allocated memory that holds unquoted name, which the caller
|
|
* should free when done. Updates endp pointer to point at
|
|
* one past the ending double quote if given.
|
|
*/
|
|
|
|
char *unquote_c_style(const char *quoted, const char **endp)
|
|
{
|
|
const char *sp;
|
|
char *name = NULL, *outp = NULL;
|
|
int count = 0, ch, ac;
|
|
|
|
#undef EMIT
|
|
#define EMIT(c) (outp ? (*outp++ = (c)) : (count++))
|
|
|
|
if (*quoted++ != '"')
|
|
return NULL;
|
|
|
|
while (1) {
|
|
/* first pass counts and allocates, second pass fills */
|
|
for (sp = quoted; (ch = *sp++) != '"'; ) {
|
|
if (ch == '\\') {
|
|
switch (ch = *sp++) {
|
|
case 'a': ch = '\a'; break;
|
|
case 'b': ch = '\b'; break;
|
|
case 'f': ch = '\f'; break;
|
|
case 'n': ch = '\n'; break;
|
|
case 'r': ch = '\r'; break;
|
|
case 't': ch = '\t'; break;
|
|
case 'v': ch = '\v'; break;
|
|
|
|
case '\\': case '"':
|
|
break; /* verbatim */
|
|
|
|
case '0'...'7':
|
|
/* octal */
|
|
ac = ((ch - '0') << 6);
|
|
if ((ch = *sp++) < '0' || '7' < ch)
|
|
return NULL;
|
|
ac |= ((ch - '0') << 3);
|
|
if ((ch = *sp++) < '0' || '7' < ch)
|
|
return NULL;
|
|
ac |= (ch - '0');
|
|
ch = ac;
|
|
break;
|
|
default:
|
|
return NULL; /* malformed */
|
|
}
|
|
}
|
|
EMIT(ch);
|
|
}
|
|
|
|
if (name) {
|
|
*outp = 0;
|
|
if (endp)
|
|
*endp = sp;
|
|
return name;
|
|
}
|
|
outp = name = xmalloc(count + 1);
|
|
}
|
|
}
|
|
|
|
void write_name_quoted(const char *prefix, const char *name,
|
|
int quote, FILE *out)
|
|
{
|
|
int needquote;
|
|
|
|
if (!quote) {
|
|
no_quote:
|
|
if (prefix && prefix[0])
|
|
fputs(prefix, out);
|
|
fputs(name, out);
|
|
return;
|
|
}
|
|
|
|
needquote = 0;
|
|
if (prefix && prefix[0])
|
|
needquote = quote_c_style(prefix, NULL, NULL, 0);
|
|
if (!needquote)
|
|
needquote = quote_c_style(name, NULL, NULL, 0);
|
|
if (needquote) {
|
|
fputc('"', out);
|
|
if (prefix && prefix[0])
|
|
quote_c_style(prefix, NULL, out, 1);
|
|
quote_c_style(name, NULL, out, 1);
|
|
fputc('"', out);
|
|
}
|
|
else
|
|
goto no_quote;
|
|
}
|