From 09d920831edba17fe983269a9d0d85e592dd4bb3 Mon Sep 17 00:00:00 2001 From: Junio C Hamano Date: Wed, 21 Sep 2005 02:46:32 -0700 Subject: [PATCH] Make object creation in http fetch a bit safer. Unlike write_sha1_file() that tries to create the object file in a temporary location and then move it to the final location, fetch_object could have been interrupted in the middle, leaving a corrupt file. Signed-off-by: Junio C Hamano --- http-fetch.c | 29 ++++++++++++++++++++++++----- 1 file changed, 24 insertions(+), 5 deletions(-) diff --git a/http-fetch.c b/http-fetch.c index 77f530c95..57141a8a2 100644 --- a/http-fetch.c +++ b/http-fetch.c @@ -350,13 +350,18 @@ int fetch_object(struct alt_base *repo, unsigned char *sha1) char *hex = sha1_to_hex(sha1); char *filename = sha1_file_name(sha1); unsigned char real_sha1[20]; + char tmpfile[PATH_MAX]; + int ret; char *url; char *posn; - local = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666); + snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", + get_object_directory()); + local = mkstemp(tmpfile); if (local < 0) - return error("Couldn't open local object %s\n", filename); + return error("Couldn't create temporary file %s for %s: %s\n", + tmpfile, filename, strerror(errno)); memset(&stream, 0, sizeof(stream)); @@ -386,18 +391,32 @@ int fetch_object(struct alt_base *repo, unsigned char *sha1) return -1; } + fchmod(local, 0444); close(local); inflateEnd(&stream); SHA1_Final(real_sha1, &c); if (zret != Z_STREAM_END) { - unlink(filename); + unlink(tmpfile); return error("File %s (%s) corrupt\n", hex, url); } if (memcmp(sha1, real_sha1, 20)) { - unlink(filename); + unlink(tmpfile); return error("File %s has bad hash\n", hex); } - + ret = link(tmpfile, filename); + if (ret < 0) { + /* Same Coda hack as in write_sha1_file(sha1_file.c) */ + ret = errno; + if (ret == EXDEV && !rename(tmpfile, filename)) + goto out; + } + unlink(tmpfile); + if (ret) { + if (ret != EEXIST) + return error("unable to write sha1 filename %s: %s", + filename, strerror(ret)); + } + out: pull_say("got %s\n", hex); return 0; } -- 2.26.2