http: use strbufs instead of fixed buffers

We keep the names of incoming packs and objects in fixed
PATH_MAX-size buffers, and snprintf() into them. This is
unlikely to end up with truncated filenames, but it is
possible (especially on systems where PATH_MAX is shorter
than actual paths can be). Let's switch to using strbufs,
which makes the question go away entirely.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Jeff King 2018-05-18 18:56:37 -07:00 committed by Junio C Hamano
parent 468165c1d8
commit 390c6cbc5e
2 changed files with 38 additions and 32 deletions

66
http.c
View file

@ -2087,6 +2087,7 @@ void release_http_pack_request(struct http_pack_request *preq)
preq->packfile = NULL;
}
preq->slot = NULL;
strbuf_release(&preq->tmpfile);
free(preq->url);
free(preq);
}
@ -2109,19 +2110,19 @@ int finish_http_pack_request(struct http_pack_request *preq)
lst = &((*lst)->next);
*lst = (*lst)->next;
if (!strip_suffix(preq->tmpfile, ".pack.temp", &len))
if (!strip_suffix(preq->tmpfile.buf, ".pack.temp", &len))
die("BUG: pack tmpfile does not end in .pack.temp?");
tmp_idx = xstrfmt("%.*s.idx.temp", (int)len, preq->tmpfile);
tmp_idx = xstrfmt("%.*s.idx.temp", (int)len, preq->tmpfile.buf);
argv_array_push(&ip.args, "index-pack");
argv_array_pushl(&ip.args, "-o", tmp_idx, NULL);
argv_array_push(&ip.args, preq->tmpfile);
argv_array_push(&ip.args, preq->tmpfile.buf);
ip.git_cmd = 1;
ip.no_stdin = 1;
ip.no_stdout = 1;
if (run_command(&ip)) {
unlink(preq->tmpfile);
unlink(preq->tmpfile.buf);
unlink(tmp_idx);
free(tmp_idx);
return -1;
@ -2129,7 +2130,7 @@ int finish_http_pack_request(struct http_pack_request *preq)
unlink(sha1_pack_index_name(p->sha1));
if (finalize_object_file(preq->tmpfile, sha1_pack_name(p->sha1))
if (finalize_object_file(preq->tmpfile.buf, sha1_pack_name(p->sha1))
|| finalize_object_file(tmp_idx, sha1_pack_index_name(p->sha1))) {
free(tmp_idx);
return -1;
@ -2148,6 +2149,7 @@ struct http_pack_request *new_http_pack_request(
struct http_pack_request *preq;
preq = xcalloc(1, sizeof(*preq));
strbuf_init(&preq->tmpfile, 0);
preq->target = target;
end_url_with_slash(&buf, base_url);
@ -2155,12 +2157,11 @@ struct http_pack_request *new_http_pack_request(
sha1_to_hex(target->sha1));
preq->url = strbuf_detach(&buf, NULL);
snprintf(preq->tmpfile, sizeof(preq->tmpfile), "%s.temp",
sha1_pack_name(target->sha1));
preq->packfile = fopen(preq->tmpfile, "a");
strbuf_addf(&preq->tmpfile, "%s.temp", sha1_pack_name(target->sha1));
preq->packfile = fopen(preq->tmpfile.buf, "a");
if (!preq->packfile) {
error("Unable to open local file %s for pack",
preq->tmpfile);
preq->tmpfile.buf);
goto abort;
}
@ -2187,6 +2188,7 @@ struct http_pack_request *new_http_pack_request(
return preq;
abort:
strbuf_release(&preq->tmpfile);
free(preq->url);
free(preq);
return NULL;
@ -2237,7 +2239,7 @@ struct http_object_request *new_http_object_request(const char *base_url,
{
char *hex = sha1_to_hex(sha1);
struct strbuf filename = STRBUF_INIT;
char prevfile[PATH_MAX];
struct strbuf prevfile = STRBUF_INIT;
int prevlocal;
char prev_buf[PREV_BUF_SIZE];
ssize_t prev_read = 0;
@ -2245,40 +2247,41 @@ struct http_object_request *new_http_object_request(const char *base_url,
struct http_object_request *freq;
freq = xcalloc(1, sizeof(*freq));
strbuf_init(&freq->tmpfile, 0);
hashcpy(freq->sha1, sha1);
freq->localfile = -1;
sha1_file_name(&filename, sha1);
snprintf(freq->tmpfile, sizeof(freq->tmpfile),
"%s.temp", filename.buf);
strbuf_addf(&freq->tmpfile, "%s.temp", filename.buf);
snprintf(prevfile, sizeof(prevfile), "%s.prev", filename.buf);
unlink_or_warn(prevfile);
rename(freq->tmpfile, prevfile);
unlink_or_warn(freq->tmpfile);
strbuf_addf(&prevfile, "%s.prev", filename.buf);
unlink_or_warn(prevfile.buf);
rename(freq->tmpfile.buf, prevfile.buf);
unlink_or_warn(freq->tmpfile.buf);
strbuf_release(&filename);
if (freq->localfile != -1)
error("fd leakage in start: %d", freq->localfile);
freq->localfile = open(freq->tmpfile,
freq->localfile = open(freq->tmpfile.buf,
O_WRONLY | O_CREAT | O_EXCL, 0666);
/*
* This could have failed due to the "lazy directory creation";
* try to mkdir the last path component.
*/
if (freq->localfile < 0 && errno == ENOENT) {
char *dir = strrchr(freq->tmpfile, '/');
char *dir = strrchr(freq->tmpfile.buf, '/');
if (dir) {
*dir = 0;
mkdir(freq->tmpfile, 0777);
mkdir(freq->tmpfile.buf, 0777);
*dir = '/';
}
freq->localfile = open(freq->tmpfile,
freq->localfile = open(freq->tmpfile.buf,
O_WRONLY | O_CREAT | O_EXCL, 0666);
}
if (freq->localfile < 0) {
error_errno("Couldn't create temporary file %s", freq->tmpfile);
error_errno("Couldn't create temporary file %s",
freq->tmpfile.buf);
goto abort;
}
@ -2292,7 +2295,7 @@ struct http_object_request *new_http_object_request(const char *base_url,
* If a previous temp file is present, process what was already
* fetched.
*/
prevlocal = open(prevfile, O_RDONLY);
prevlocal = open(prevfile.buf, O_RDONLY);
if (prevlocal != -1) {
do {
prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
@ -2309,7 +2312,8 @@ struct http_object_request *new_http_object_request(const char *base_url,
} while (prev_read > 0);
close(prevlocal);
}
unlink_or_warn(prevfile);
unlink_or_warn(prevfile.buf);
strbuf_release(&prevfile);
/*
* Reset inflate/SHA1 if there was an error reading the previous temp
@ -2324,7 +2328,7 @@ struct http_object_request *new_http_object_request(const char *base_url,
lseek(freq->localfile, 0, SEEK_SET);
if (ftruncate(freq->localfile, 0) < 0) {
error_errno("Couldn't truncate temporary file %s",
freq->tmpfile);
freq->tmpfile.buf);
goto abort;
}
}
@ -2354,6 +2358,7 @@ struct http_object_request *new_http_object_request(const char *base_url,
return freq;
abort:
strbuf_release(&prevfile);
free(freq->url);
free(freq);
return NULL;
@ -2381,25 +2386,25 @@ int finish_http_object_request(struct http_object_request *freq)
if (freq->http_code == 416) {
warning("requested range invalid; we may already have all the data.");
} else if (freq->curl_result != CURLE_OK) {
if (stat(freq->tmpfile, &st) == 0)
if (stat(freq->tmpfile.buf, &st) == 0)
if (st.st_size == 0)
unlink_or_warn(freq->tmpfile);
unlink_or_warn(freq->tmpfile.buf);
return -1;
}
git_inflate_end(&freq->stream);
git_SHA1_Final(freq->real_sha1, &freq->c);
if (freq->zret != Z_STREAM_END) {
unlink_or_warn(freq->tmpfile);
unlink_or_warn(freq->tmpfile.buf);
return -1;
}
if (hashcmp(freq->sha1, freq->real_sha1)) {
unlink_or_warn(freq->tmpfile);
unlink_or_warn(freq->tmpfile.buf);
return -1;
}
sha1_file_name(&filename, freq->sha1);
freq->rename = finalize_object_file(freq->tmpfile, filename.buf);
freq->rename = finalize_object_file(freq->tmpfile.buf, filename.buf);
strbuf_release(&filename);
return freq->rename;
@ -2407,7 +2412,7 @@ int finish_http_object_request(struct http_object_request *freq)
void abort_http_object_request(struct http_object_request *freq)
{
unlink_or_warn(freq->tmpfile);
unlink_or_warn(freq->tmpfile.buf);
release_http_object_request(freq);
}
@ -2427,4 +2432,5 @@ void release_http_object_request(struct http_object_request *freq)
release_active_slot(freq->slot);
freq->slot = NULL;
}
strbuf_release(&freq->tmpfile);
}

4
http.h
View file

@ -200,7 +200,7 @@ struct http_pack_request {
struct packed_git *target;
struct packed_git **lst;
FILE *packfile;
char tmpfile[PATH_MAX];
struct strbuf tmpfile;
struct active_request_slot *slot;
};
@ -212,7 +212,7 @@ extern void release_http_pack_request(struct http_pack_request *preq);
/* Helpers for fetching object */
struct http_object_request {
char *url;
char tmpfile[PATH_MAX];
struct strbuf tmpfile;
int localfile;
CURLcode curl_result;
char errorstr[CURL_ERROR_SIZE];