Commit 393fb88d6194f734060bc169da1b73f70648a3ab
2020-03-21T17:28:29
handle reference-only updates in 'got fetch' where server sends an empty pack
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diff --git a/lib/fetch.c b/lib/fetch.c
index 1cdd3ca..30d3009 100644
--- a/lib/fetch.c
+++ b/lib/fetch.c
@@ -410,6 +410,8 @@ got_fetch_pack(struct got_object_id **pack_hash, struct got_pathlist_head *refs,
struct got_reflist_head my_refs;
struct got_reflist_entry *re;
off_t packfile_size = 0;
+ struct got_packfile_hdr pack_hdr;
+ uint32_t nobj = 0;
char *ref_prefix = NULL;
size_t ref_prefixlen = 0;
char *path;
@@ -519,11 +521,6 @@ got_fetch_pack(struct got_object_id **pack_hash, struct got_pathlist_head *refs,
if (err)
goto done;
}
- npackfd = dup(packfd);
- if (npackfd == -1) {
- err = got_error_from_errno("dup");
- goto done;
- }
if (list_refs_only) {
idxfd = got_opentempfd();
if (idxfd == -1) {
@@ -584,14 +581,15 @@ got_fetch_pack(struct got_object_id **pack_hash, struct got_pathlist_head *refs,
if (err != NULL)
goto done;
nfetchfd = -1;
- err = got_privsep_send_fetch_outfd(&fetchibuf, npackfd);
- if (err != NULL)
- goto done;
npackfd = dup(packfd);
if (npackfd == -1) {
err = got_error_from_errno("dup");
goto done;
}
+ err = got_privsep_send_fetch_outfd(&fetchibuf, npackfd);
+ if (err != NULL)
+ goto done;
+ npackfd = -1;
packfile_size = 0;
progress = calloc(GOT_FETCH_PKTMAX, 1);
@@ -671,17 +669,70 @@ got_fetch_pack(struct got_object_id **pack_hash, struct got_pathlist_head *refs,
goto done;
}
+ if (lseek(packfd, 0, SEEK_SET) == -1) {
+ err = got_error_from_errno("lseek");
+ goto done;
+ }
+
/* If zero data was fetched without error we are already up-to-date. */
if (packfile_size == 0)
goto done;
+ else if (packfile_size < sizeof(pack_hdr) + SHA1_DIGEST_LENGTH) {
+ err = got_error_msg(GOT_ERR_BAD_PACKFILE, "short pack file");
+ goto done;
+ } else {
+ ssize_t n;
+
+ n = read(packfd, &pack_hdr, sizeof(pack_hdr));
+ if (n == -1) {
+ err = got_error_from_errno("read");
+ goto done;
+ }
+ if (n != sizeof(pack_hdr)) {
+ err = got_error(GOT_ERR_IO);
+ goto done;
+ }
+ if (pack_hdr.signature != htobe32(GOT_PACKFILE_SIGNATURE)) {
+ err = got_error_msg(GOT_ERR_BAD_PACKFILE,
+ "bad pack file signature");
+ goto done;
+ }
+ if (pack_hdr.version != htobe32(GOT_PACKFILE_VERSION)) {
+ err = got_error_msg(GOT_ERR_BAD_PACKFILE,
+ "bad pack file version");
+ goto done;
+ }
+ nobj = betoh32(pack_hdr.nobjects);
+ if (nobj == 0 &&
+ packfile_size > sizeof(pack_hdr) + SHA1_DIGEST_LENGTH)
+ return got_error_msg(GOT_ERR_BAD_PACKFILE,
+ "bad pack file with zero objects");
+ if (nobj != 0 &&
+ packfile_size <= sizeof(pack_hdr) + SHA1_DIGEST_LENGTH)
+ return got_error_msg(GOT_ERR_BAD_PACKFILE,
+ "empty pack file with non-zero object count");
+ }
+
+ /*
+ * If the pack file contains no objects, we may only need to update
+ * references in our repository. The caller will take care of that.
+ */
+ if (nobj == 0)
+ goto done;
if (lseek(packfd, 0, SEEK_SET) == -1) {
err = got_error_from_errno("lseek");
goto done;
}
+
err = check_pack_hash(packfd, packfile_size, (*pack_hash)->sha1);
if (err)
goto done;
+
+ if (lseek(packfd, 0, SEEK_SET) == -1) {
+ err = got_error_from_errno("lseek");
+ goto done;
+ }
if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_idxfds) == -1) {
err = got_error_from_errno("socketpair");
@@ -700,6 +751,11 @@ got_fetch_pack(struct got_object_id **pack_hash, struct got_pathlist_head *refs,
}
imsg_init(&idxibuf, imsg_idxfds[0]);
+ npackfd = dup(packfd);
+ if (npackfd == -1) {
+ err = got_error_from_errno("dup");
+ goto done;
+ }
err = got_privsep_send_index_pack_req(&idxibuf, (*pack_hash)->sha1,
npackfd);
if (err != NULL)