diff --git a/Documentation/git-http-backend.txt b/Documentation/git-http-backend.txt
index 3ca18c4de51..9268fb6b1ea 100644
--- a/Documentation/git-http-backend.txt
+++ b/Documentation/git-http-backend.txt
@@ -255,6 +255,15 @@ The GIT_HTTP_EXPORT_ALL environmental variable may be passed to
'git-http-backend' to bypass the check for the "git-daemon-export-ok"
file in each repository before allowing export of that repository.
+The `GIT_HTTP_MAX_REQUEST_BUFFER` environment variable (or the
+`http.maxRequestBuffer` config variable) may be set to change the
+largest ref negotiation request that git will handle during a fetch; any
+fetch requiring a larger buffer will not succeed. This value should not
+normally need to be changed, but may be helpful if you are fetching from
+a repository with an extremely large number of refs. The value can be
+specified with a unit (e.g., `100M` for 100 megabytes). The default is
+10 megabytes.
+
The backend process sets GIT_COMMITTER_NAME to '$REMOTE_USER' and
GIT_COMMITTER_EMAIL to '$\{REMOTE_USER}@http.$\{REMOTE_ADDR\}',
ensuring that any reflogs created by 'git-receive-pack' contain some
diff --git a/http-backend.c b/http-backend.c
index b6c0484fb24..6bf139b7687 100644
--- a/http-backend.c
+++ b/http-backend.c
@@ -13,18 +13,20 @@ static const char content_type[] = "Content-Type";
static const char content_length[] = "Content-Length";
static const char last_modified[] = "Last-Modified";
static int getanyfile = 1;
+static unsigned long max_request_buffer = 10 * 1024 * 1024;
static struct string_list *query_params;
struct rpc_service {
const char *name;
const char *config_name;
+ unsigned buffer_input : 1;
signed enabled : 2;
};
static struct rpc_service rpc_service[] = {
- { "upload-pack", "uploadpack", 1 },
- { "receive-pack", "receivepack", -1 },
+ { "upload-pack", "uploadpack", 1, 1 },
+ { "receive-pack", "receivepack", 0, -1 },
};
static struct string_list *get_parameters(void)
@@ -225,6 +227,7 @@ static void http_config(void)
struct strbuf var = STRBUF_INIT;
git_config_get_bool("http.getanyfile", &getanyfile);
+ git_config_get_ulong("http.maxrequestbuffer", &max_request_buffer);
for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
struct rpc_service *svc = &rpc_service[i];
@@ -266,9 +269,52 @@ static struct rpc_service *select_service(const char *name)
return svc;
}
-static void inflate_request(const char *prog_name, int out)
+/*
+ * This is basically strbuf_read(), except that if we
+ * hit max_request_buffer we die (we'd rather reject a
+ * maliciously large request than chew up infinite memory).
+ */
+static ssize_t read_request(int fd, unsigned char **out)
+{
+ size_t len = 0, alloc = 8192;
+ unsigned char *buf = xmalloc(alloc);
+
+ if (max_request_buffer < alloc)
+ max_request_buffer = alloc;
+
+ while (1) {
+ ssize_t cnt;
+
+ cnt = read_in_full(fd, buf + len, alloc - len);
+ if (cnt < 0) {
+ free(buf);
+ return -1;
+ }
+
+ /* partial read from read_in_full means we hit EOF */
+ len += cnt;
+ if (len < alloc) {
+ *out = buf;
+ return len;
+ }
+
+ /* otherwise, grow and try again (if we can) */
+ if (alloc == max_request_buffer)
+ die("request was larger than our maximum size (%lu);"
+ " try setting GIT_HTTP_MAX_REQUEST_BUFFER",
+ max_request_buffer);
+
+ alloc = alloc_nr(alloc);
+ if (alloc > max_request_buffer)
+ alloc = max_request_buffer;
+ REALLOC_ARRAY(buf, alloc);
+ }
+}
+
+static void inflate_request(const char *prog_name, int out, int buffer_input)
{
git_zstream stream;
+ unsigned char *full_request = NULL;
unsigned char in_buf[8192];
unsigned char out_buf[8192];
unsigned long cnt = 0;
@@ -277,11 +323,21 @@ static void inflate_request(const char *prog_name, int out)
git_inflate_init_gzip_only(&stream);
while (1) {
- ssize_t n = xread(0, in_buf, sizeof(in_buf));
+ ssize_t n;
+
+ if (buffer_input) {
+ if (full_request)
+ n = 0; /* nothing left to read */
+ else
+ n = read_request(0, &full_request);
+ stream.next_in = full_request;
+ } else {
+ n = xread(0, in_buf, sizeof(in_buf));
+ stream.next_in = in_buf;
+ }
+
if (n <= 0)
die("request ended in the middle of the gzip stream");
-
- stream.next_in = in_buf;
stream.avail_in = n;
while (0 < stream.avail_in) {
@@ -307,9 +363,22 @@ static void inflate_request(const char *prog_name, int out)
done:
git_inflate_end(&stream);
close(out);
+ free(full_request);
}
-static void run_service(const char **argv)
+static void copy_request(const char *prog_name, int out)
+{
+ unsigned char *buf;
+ ssize_t n = read_request(0, &buf);
+ if (n < 0)
+ die_errno("error reading request body");
+ if (write_in_full(out, buf, n) != n)
+ die("%s aborted reading request", prog_name);
+ close(out);
+ free(buf);
+}
+
+static void run_service(const char **argv, int buffer_input)
{
const char *encoding = getenv("HTTP_CONTENT_ENCODING");
const char *user = getenv("REMOTE_USER");
@@ -334,7 +403,7 @@ static void run_service(const char **argv)
"GIT_COMMITTER_EMAIL=%s@http.%s", user, host);
cld.argv = argv;
- if (gzipped_request)
+ if (buffer_input || gzipped_request)
cld.in = -1;
cld.git_cmd = 1;
if (start_command(&cld))
@@ -342,7 +411,9 @@ static void run_service(const char **argv)
close(1);
if (gzipped_request)
- inflate_request(argv[0], cld.in);
+ inflate_request(argv[0], cld.in, buffer_input);
+ else if (buffer_input)
+ copy_request(argv[0], cld.in);
else
close(0);
@@ -392,7 +463,7 @@ static void get_info_refs(char *arg)
packet_flush(1);
argv[0] = svc->name;
- run_service(argv);
+ run_service(argv, 0);
} else {
select_getanyfile();
@@ -496,25 +567,28 @@ static void service_rpc(char *service_name)
end_headers();
argv[0] = svc->name;
- run_service(argv);
+ run_service(argv, svc->buffer_input);
strbuf_release(&buf);
}
+static int dead;
static NORETURN void die_webcgi(const char *err, va_list params)
{
- static int dead;
+ if (dead <= 1) {
+ vreportf("fatal: ", err, params);
- if (!dead) {
- dead = 1;
http_status(500, "Internal Server Error");
hdr_nocache();
end_headers();
-
- vreportf("fatal: ", err, params);
}
exit(0); /* we successfully reported a failure ;-) */
}
+static int die_webcgi_recursing(void)
+{
+ return dead++ > 1;
+}
+
static char* getdir(void)
{
struct strbuf buf = STRBUF_INIT;
@@ -569,6 +643,7 @@ int main(int argc, char **argv)
git_extract_argv0_path(argv[0]);
set_die_routine(die_webcgi);
+ set_die_is_recursing_routine(die_webcgi_recursing);
if (!method)
die("No REQUEST_METHOD from server");
@@ -619,6 +694,9 @@ int main(int argc, char **argv)
not_found("Repository not exported: '%s'", dir);
http_config();
+ max_request_buffer = git_env_ulong("GIT_HTTP_MAX_REQUEST_BUFFER",
+ max_request_buffer);
+
cmd->imp(cmd_arg);
return 0;
}
diff --git a/t/t5551-http-fetch-smart.sh b/t/t5551-http-fetch-smart.sh
index 2b293119015..58207d88250 100755
--- a/t/t5551-http-fetch-smart.sh
+++ b/t/t5551-http-fetch-smart.sh
@@ -218,27 +218,35 @@ test_expect_success 'transfer.hiderefs works over smart-http' '
git -C hidden.git rev-parse --verify b
'
-test_expect_success 'create 2,000 tags in the repo' '
- (
- cd "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
- for i in $(test_seq 2000)
+# create an arbitrary number of tags, numbered from tag-$1 to tag-$2
+create_tags () {
+ rm -f marks &&
+ for i in $(test_seq "$1" "$2")
do
- echo "commit refs/heads/too-many-refs"
- echo "mark :$i"
- echo "committer git <git@example.com> $i +0000"
- echo "data 0"
- echo "M 644 inline bla.txt"
- echo "data 4"
- echo "bla"
+ # don't use here-doc, because it requires a process
+ # per loop iteration
+ echo "commit refs/heads/too-many-refs-$1" &&
+ echo "mark :$i" &&
+ echo "committer git <git@example.com> $i +0000" &&
+ echo "data 0" &&
+ echo "M 644 inline bla.txt" &&
+ echo "data 4" &&
+ echo "bla" &&
# make every commit dangling by always
# rewinding the branch after each commit
- echo "reset refs/heads/too-many-refs"
- echo "from :1"
+ echo "reset refs/heads/too-many-refs-$1" &&
+ echo "from :$1"
done | git fast-import --export-marks=marks &&
# now assign tags to all the dangling commits we created above
tag=$(perl -e "print \"bla\" x 30") &&
sed -e "s|^:\([^ ]*\) \(.*\)$|\2 refs/tags/$tag-\1|" <marks >>packed-refs
+}
+
+test_expect_success 'create 2,000 tags in the repo' '
+ (
+ cd "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
+ create_tags 1 2000
)
'
@@ -259,5 +267,20 @@ test_expect_success 'large fetch-pack requests can be split across POSTs' '
test_line_count = 2 posts
'
+test_expect_success EXPENSIVE 'http can handle enormous ref negotiation' '
+ (
+ cd "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
+ create_tags 2001 50000
+ ) &&
+ git -C too-many-refs fetch -q --tags &&
+ (
+ cd "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
+ create_tags 50001 100000
+ ) &&
+ git -C too-many-refs fetch -q --tags &&
+ git -C too-many-refs for-each-ref refs/tags >tags &&
+ test_line_count = 100000 tags
+'
+
stop_httpd
test_done