upload-pack: tighten request validation.

This makes sure what the other end asks for are among what we
offered to give them.  Otherwise we would end up running
git-rev-list with 20-byte nonsense, only to find it either die
(because the object was not found) or waste time (because we
ended up serving that phony 'client').

Also avoid wasting needs_sha1 pool to record duplicates, and
detect cloning requests better.

[this used to be on top of Johannes fetch-pack enhancements,
 which we are rewinding it for further testing for now, so
 the commit is rebased.]

Signed-off-by: Junio C Hamano <junkio@cox.net>
This commit is contained in:
Junio C Hamano 2005-10-24 18:59:18 -07:00
parent 9e48b38999
commit 565ebbf79f

View File

@ -6,9 +6,11 @@
static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
#define OUR_REF (1U << 1)
#define WANTED (1U << 2)
#define MAX_HAS 256
#define MAX_NEEDS 256
static int nr_has = 0, nr_needs = 0;
static int nr_has = 0, nr_needs = 0, nr_our_refs = 0;
static unsigned char has_sha1[MAX_HAS][20];
static unsigned char needs_sha1[MAX_NEEDS][20];
static unsigned int timeout = 0;
@ -29,6 +31,7 @@ static void create_pack_file(void)
{
int fd[2];
pid_t pid;
int create_full_pack = (nr_our_refs == nr_needs && !nr_has);
if (pipe(fd) < 0)
die("git-upload-pack: unable to create pipe");
@ -43,8 +46,8 @@ static void create_pack_file(void)
char *buf;
char **p;
if (MAX_NEEDS <= nr_needs)
args = nr_has + 10;
if (create_full_pack)
args = 10;
else
args = nr_has + nr_needs + 5;
argv = xmalloc(args * sizeof(char *));
@ -151,6 +154,7 @@ static int receive_needs(void)
needs = 0;
for (;;) {
struct object *o;
unsigned char dummy[20], *sha1_buf;
len = packet_read_line(0, line, sizeof(line));
reset_timeout();
@ -170,7 +174,22 @@ static int receive_needs(void)
if (strncmp("want ", line, 5) || get_sha1_hex(line+5, sha1_buf))
die("git-upload-pack: protocol error, "
"expected to get sha, not '%s'", line);
needs++;
/* We have sent all our refs already, and the other end
* should have chosen out of them; otherwise they are
* asking for nonsense.
*
* Hmph. We may later want to allow "want" line that
* asks for something like "master~10" (symbolic)...
* would it make sense? I don't know.
*/
o = lookup_object(sha1_buf);
if (!o || !(o->flags & OUR_REF))
die("git-upload-pack: not our ref %s", line+5);
if (!(o->flags & WANTED)) {
o->flags |= WANTED;
needs++;
}
}
}
@ -179,6 +198,10 @@ static int send_ref(const char *refname, const unsigned char *sha1)
struct object *o = parse_object(sha1);
packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
if (!(o->flags & OUR_REF)) {
o->flags |= OUR_REF;
nr_our_refs++;
}
if (o->type == tag_type) {
o = deref_tag(o);
packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);