git/http-backend.c
Jeff King cdf4fb8e33 pkt-line: drop safe_write function
This is just write_or_die by another name. The one
distinction is that write_or_die will treat EPIPE specially
by suppressing error messages. That's fine, as we die by
SIGPIPE anyway (and in the off chance that it is disabled,
write_or_die will simulate it).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-20 13:42:21 -08:00

601 lines
13 KiB
C

#include "cache.h"
#include "refs.h"
#include "pkt-line.h"
#include "object.h"
#include "tag.h"
#include "exec_cmd.h"
#include "run-command.h"
#include "string-list.h"
#include "url.h"
#include "argv-array.h"
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 struct string_list *query_params;
struct rpc_service {
const char *name;
const char *config_name;
signed enabled : 2;
};
static struct rpc_service rpc_service[] = {
{ "upload-pack", "uploadpack", 1 },
{ "receive-pack", "receivepack", -1 },
};
static struct string_list *get_parameters(void)
{
if (!query_params) {
const char *query = getenv("QUERY_STRING");
query_params = xcalloc(1, sizeof(*query_params));
while (query && *query) {
char *name = url_decode_parameter_name(&query);
char *value = url_decode_parameter_value(&query);
struct string_list_item *i;
i = string_list_lookup(query_params, name);
if (!i)
i = string_list_insert(query_params, name);
else
free(i->util);
i->util = value;
}
}
return query_params;
}
static const char *get_parameter(const char *name)
{
struct string_list_item *i;
i = string_list_lookup(get_parameters(), name);
return i ? i->util : NULL;
}
__attribute__((format (printf, 2, 3)))
static void format_write(int fd, const char *fmt, ...)
{
static char buffer[1024];
va_list args;
unsigned n;
va_start(args, fmt);
n = vsnprintf(buffer, sizeof(buffer), fmt, args);
va_end(args);
if (n >= sizeof(buffer))
die("protocol error: impossibly long line");
write_or_die(fd, buffer, n);
}
static void http_status(unsigned code, const char *msg)
{
format_write(1, "Status: %u %s\r\n", code, msg);
}
static void hdr_str(const char *name, const char *value)
{
format_write(1, "%s: %s\r\n", name, value);
}
static void hdr_int(const char *name, uintmax_t value)
{
format_write(1, "%s: %" PRIuMAX "\r\n", name, value);
}
static void hdr_date(const char *name, unsigned long when)
{
const char *value = show_date(when, 0, DATE_RFC2822);
hdr_str(name, value);
}
static void hdr_nocache(void)
{
hdr_str("Expires", "Fri, 01 Jan 1980 00:00:00 GMT");
hdr_str("Pragma", "no-cache");
hdr_str("Cache-Control", "no-cache, max-age=0, must-revalidate");
}
static void hdr_cache_forever(void)
{
unsigned long now = time(NULL);
hdr_date("Date", now);
hdr_date("Expires", now + 31536000);
hdr_str("Cache-Control", "public, max-age=31536000");
}
static void end_headers(void)
{
write_or_die(1, "\r\n", 2);
}
__attribute__((format (printf, 1, 2)))
static NORETURN void not_found(const char *err, ...)
{
va_list params;
http_status(404, "Not Found");
hdr_nocache();
end_headers();
va_start(params, err);
if (err && *err)
vfprintf(stderr, err, params);
va_end(params);
exit(0);
}
__attribute__((format (printf, 1, 2)))
static NORETURN void forbidden(const char *err, ...)
{
va_list params;
http_status(403, "Forbidden");
hdr_nocache();
end_headers();
va_start(params, err);
if (err && *err)
vfprintf(stderr, err, params);
va_end(params);
exit(0);
}
static void select_getanyfile(void)
{
if (!getanyfile)
forbidden("Unsupported service: getanyfile");
}
static void send_strbuf(const char *type, struct strbuf *buf)
{
hdr_int(content_length, buf->len);
hdr_str(content_type, type);
end_headers();
write_or_die(1, buf->buf, buf->len);
}
static void send_local_file(const char *the_type, const char *name)
{
const char *p = git_path("%s", name);
size_t buf_alloc = 8192;
char *buf = xmalloc(buf_alloc);
int fd;
struct stat sb;
fd = open(p, O_RDONLY);
if (fd < 0)
not_found("Cannot open '%s': %s", p, strerror(errno));
if (fstat(fd, &sb) < 0)
die_errno("Cannot stat '%s'", p);
hdr_int(content_length, sb.st_size);
hdr_str(content_type, the_type);
hdr_date(last_modified, sb.st_mtime);
end_headers();
for (;;) {
ssize_t n = xread(fd, buf, buf_alloc);
if (n < 0)
die_errno("Cannot read '%s'", p);
if (!n)
break;
write_or_die(1, buf, n);
}
close(fd);
free(buf);
}
static void get_text_file(char *name)
{
select_getanyfile();
hdr_nocache();
send_local_file("text/plain", name);
}
static void get_loose_object(char *name)
{
select_getanyfile();
hdr_cache_forever();
send_local_file("application/x-git-loose-object", name);
}
static void get_pack_file(char *name)
{
select_getanyfile();
hdr_cache_forever();
send_local_file("application/x-git-packed-objects", name);
}
static void get_idx_file(char *name)
{
select_getanyfile();
hdr_cache_forever();
send_local_file("application/x-git-packed-objects-toc", name);
}
static int http_config(const char *var, const char *value, void *cb)
{
if (!strcmp(var, "http.getanyfile")) {
getanyfile = git_config_bool(var, value);
return 0;
}
if (!prefixcmp(var, "http.")) {
int i;
for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
struct rpc_service *svc = &rpc_service[i];
if (!strcmp(var + 5, svc->config_name)) {
svc->enabled = git_config_bool(var, value);
return 0;
}
}
}
/* we are not interested in parsing any other configuration here */
return 0;
}
static struct rpc_service *select_service(const char *name)
{
struct rpc_service *svc = NULL;
int i;
if (prefixcmp(name, "git-"))
forbidden("Unsupported service: '%s'", name);
for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
struct rpc_service *s = &rpc_service[i];
if (!strcmp(s->name, name + 4)) {
svc = s;
break;
}
}
if (!svc)
forbidden("Unsupported service: '%s'", name);
if (svc->enabled < 0) {
const char *user = getenv("REMOTE_USER");
svc->enabled = (user && *user) ? 1 : 0;
}
if (!svc->enabled)
forbidden("Service not enabled: '%s'", svc->name);
return svc;
}
static void inflate_request(const char *prog_name, int out)
{
git_zstream stream;
unsigned char in_buf[8192];
unsigned char out_buf[8192];
unsigned long cnt = 0;
memset(&stream, 0, sizeof(stream));
git_inflate_init_gzip_only(&stream);
while (1) {
ssize_t n = xread(0, in_buf, sizeof(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) {
int ret;
stream.next_out = out_buf;
stream.avail_out = sizeof(out_buf);
ret = git_inflate(&stream, Z_NO_FLUSH);
if (ret != Z_OK && ret != Z_STREAM_END)
die("zlib error inflating request, result %d", ret);
n = stream.total_out - cnt;
if (write_in_full(out, out_buf, n) != n)
die("%s aborted reading request", prog_name);
cnt += n;
if (ret == Z_STREAM_END)
goto done;
}
}
done:
git_inflate_end(&stream);
close(out);
}
static void run_service(const char **argv)
{
const char *encoding = getenv("HTTP_CONTENT_ENCODING");
const char *user = getenv("REMOTE_USER");
const char *host = getenv("REMOTE_ADDR");
struct argv_array env = ARGV_ARRAY_INIT;
int gzipped_request = 0;
struct child_process cld;
if (encoding && !strcmp(encoding, "gzip"))
gzipped_request = 1;
else if (encoding && !strcmp(encoding, "x-gzip"))
gzipped_request = 1;
if (!user || !*user)
user = "anonymous";
if (!host || !*host)
host = "(none)";
if (!getenv("GIT_COMMITTER_NAME"))
argv_array_pushf(&env, "GIT_COMMITTER_NAME=%s", user);
if (!getenv("GIT_COMMITTER_EMAIL"))
argv_array_pushf(&env, "GIT_COMMITTER_EMAIL=%s@http.%s",
user, host);
memset(&cld, 0, sizeof(cld));
cld.argv = argv;
cld.env = env.argv;
if (gzipped_request)
cld.in = -1;
cld.git_cmd = 1;
if (start_command(&cld))
exit(1);
close(1);
if (gzipped_request)
inflate_request(argv[0], cld.in);
else
close(0);
if (finish_command(&cld))
exit(1);
argv_array_clear(&env);
}
static int show_text_ref(const char *name, const unsigned char *sha1,
int flag, void *cb_data)
{
struct strbuf *buf = cb_data;
struct object *o = parse_object(sha1);
if (!o)
return 0;
strbuf_addf(buf, "%s\t%s\n", sha1_to_hex(sha1), name);
if (o->type == OBJ_TAG) {
o = deref_tag(o, name, 0);
if (!o)
return 0;
strbuf_addf(buf, "%s\t%s^{}\n", sha1_to_hex(o->sha1), name);
}
return 0;
}
static void get_info_refs(char *arg)
{
const char *service_name = get_parameter("service");
struct strbuf buf = STRBUF_INIT;
hdr_nocache();
if (service_name) {
const char *argv[] = {NULL /* service name */,
"--stateless-rpc", "--advertise-refs",
".", NULL};
struct rpc_service *svc = select_service(service_name);
strbuf_addf(&buf, "application/x-git-%s-advertisement",
svc->name);
hdr_str(content_type, buf.buf);
end_headers();
packet_write(1, "# service=git-%s\n", svc->name);
packet_flush(1);
argv[0] = svc->name;
run_service(argv);
} else {
select_getanyfile();
for_each_ref(show_text_ref, &buf);
send_strbuf("text/plain", &buf);
}
strbuf_release(&buf);
}
static void get_info_packs(char *arg)
{
size_t objdirlen = strlen(get_object_directory());
struct strbuf buf = STRBUF_INIT;
struct packed_git *p;
size_t cnt = 0;
select_getanyfile();
prepare_packed_git();
for (p = packed_git; p; p = p->next) {
if (p->pack_local)
cnt++;
}
strbuf_grow(&buf, cnt * 53 + 2);
for (p = packed_git; p; p = p->next) {
if (p->pack_local)
strbuf_addf(&buf, "P %s\n", p->pack_name + objdirlen + 6);
}
strbuf_addch(&buf, '\n');
hdr_nocache();
send_strbuf("text/plain; charset=utf-8", &buf);
strbuf_release(&buf);
}
static void check_content_type(const char *accepted_type)
{
const char *actual_type = getenv("CONTENT_TYPE");
if (!actual_type)
actual_type = "";
if (strcmp(actual_type, accepted_type)) {
http_status(415, "Unsupported Media Type");
hdr_nocache();
end_headers();
format_write(1,
"Expected POST with Content-Type '%s',"
" but received '%s' instead.\n",
accepted_type, actual_type);
exit(0);
}
}
static void service_rpc(char *service_name)
{
const char *argv[] = {NULL, "--stateless-rpc", ".", NULL};
struct rpc_service *svc = select_service(service_name);
struct strbuf buf = STRBUF_INIT;
strbuf_reset(&buf);
strbuf_addf(&buf, "application/x-git-%s-request", svc->name);
check_content_type(buf.buf);
hdr_nocache();
strbuf_reset(&buf);
strbuf_addf(&buf, "application/x-git-%s-result", svc->name);
hdr_str(content_type, buf.buf);
end_headers();
argv[0] = svc->name;
run_service(argv);
strbuf_release(&buf);
}
static NORETURN void die_webcgi(const char *err, va_list params)
{
static int dead;
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 char* getdir(void)
{
struct strbuf buf = STRBUF_INIT;
char *pathinfo = getenv("PATH_INFO");
char *root = getenv("GIT_PROJECT_ROOT");
char *path = getenv("PATH_TRANSLATED");
if (root && *root) {
if (!pathinfo || !*pathinfo)
die("GIT_PROJECT_ROOT is set but PATH_INFO is not");
if (daemon_avoid_alias(pathinfo))
die("'%s': aliased", pathinfo);
end_url_with_slash(&buf, root);
if (pathinfo[0] == '/')
pathinfo++;
strbuf_addstr(&buf, pathinfo);
return strbuf_detach(&buf, NULL);
} else if (path && *path) {
return xstrdup(path);
} else
die("No GIT_PROJECT_ROOT or PATH_TRANSLATED from server");
return NULL;
}
static struct service_cmd {
const char *method;
const char *pattern;
void (*imp)(char *);
} services[] = {
{"GET", "/HEAD$", get_text_file},
{"GET", "/info/refs$", get_info_refs},
{"GET", "/objects/info/alternates$", get_text_file},
{"GET", "/objects/info/http-alternates$", get_text_file},
{"GET", "/objects/info/packs$", get_info_packs},
{"GET", "/objects/[0-9a-f]{2}/[0-9a-f]{38}$", get_loose_object},
{"GET", "/objects/pack/pack-[0-9a-f]{40}\\.pack$", get_pack_file},
{"GET", "/objects/pack/pack-[0-9a-f]{40}\\.idx$", get_idx_file},
{"POST", "/git-upload-pack$", service_rpc},
{"POST", "/git-receive-pack$", service_rpc}
};
int main(int argc, char **argv)
{
char *method = getenv("REQUEST_METHOD");
char *dir;
struct service_cmd *cmd = NULL;
char *cmd_arg = NULL;
int i;
git_setup_gettext();
git_extract_argv0_path(argv[0]);
set_die_routine(die_webcgi);
if (!method)
die("No REQUEST_METHOD from server");
if (!strcmp(method, "HEAD"))
method = "GET";
dir = getdir();
for (i = 0; i < ARRAY_SIZE(services); i++) {
struct service_cmd *c = &services[i];
regex_t re;
regmatch_t out[1];
if (regcomp(&re, c->pattern, REG_EXTENDED))
die("Bogus regex in service table: %s", c->pattern);
if (!regexec(&re, dir, 1, out, 0)) {
size_t n;
if (strcmp(method, c->method)) {
const char *proto = getenv("SERVER_PROTOCOL");
if (proto && !strcmp(proto, "HTTP/1.1"))
http_status(405, "Method Not Allowed");
else
http_status(400, "Bad Request");
hdr_nocache();
end_headers();
return 0;
}
cmd = c;
n = out[0].rm_eo - out[0].rm_so;
cmd_arg = xmalloc(n);
memcpy(cmd_arg, dir + out[0].rm_so + 1, n-1);
cmd_arg[n-1] = '\0';
dir[out[0].rm_so] = 0;
break;
}
regfree(&re);
}
if (!cmd)
not_found("Request not supported: '%s'", dir);
setup_path();
if (!enter_repo(dir, 0))
not_found("Not a git repository: '%s'", dir);
if (!getenv("GIT_HTTP_EXPORT_ALL") &&
access("git-daemon-export-ok", F_OK) )
not_found("Repository not exported: '%s'", dir);
git_config(http_config, NULL);
cmd->imp(cmd_arg);
return 0;
}