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-rw-r--r--http-backend.c655
1 files changed, 655 insertions, 0 deletions
diff --git a/http-backend.c b/http-backend.c
new file mode 100644
index 000000000..f729488fc
--- /dev/null
+++ b/http-backend.c
@@ -0,0 +1,655 @@
+#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"
+
+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 int decode_char(const char *q)
+{
+ int i;
+ unsigned char val = 0;
+ for (i = 0; i < 2; i++) {
+ unsigned char c = *q++;
+ val <<= 4;
+ if (c >= '0' && c <= '9')
+ val += c - '0';
+ else if (c >= 'a' && c <= 'f')
+ val += c - 'a' + 10;
+ else if (c >= 'A' && c <= 'F')
+ val += c - 'A' + 10;
+ else
+ return -1;
+ }
+ return val;
+}
+
+static char *decode_parameter(const char **query, int is_name)
+{
+ const char *q = *query;
+ struct strbuf out;
+
+ strbuf_init(&out, 16);
+ do {
+ unsigned char c = *q;
+
+ if (!c)
+ break;
+ if (c == '&' || (is_name && c == '=')) {
+ q++;
+ break;
+ }
+
+ if (c == '%') {
+ int val = decode_char(q + 1);
+ if (0 <= val) {
+ strbuf_addch(&out, val);
+ q += 3;
+ continue;
+ }
+ }
+
+ if (c == '+')
+ strbuf_addch(&out, ' ');
+ else
+ strbuf_addch(&out, c);
+ q++;
+ } while (1);
+ *query = q;
+ return strbuf_detach(&out, NULL);
+}
+
+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 = decode_parameter(&query, 1);
+ char *value = decode_parameter(&query, 0);
+ struct string_list_item *i;
+
+ i = string_list_lookup(name, query_params);
+ if (!i)
+ i = string_list_insert(name, query_params);
+ 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(name, get_parameters());
+ 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");
+
+ safe_write(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)
+{
+ safe_write(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();
+ safe_write(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;
+ safe_write(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)
+{
+ z_stream stream;
+ unsigned char in_buf[8192];
+ unsigned char out_buf[8192];
+ unsigned long cnt = 0;
+ int ret;
+
+ memset(&stream, 0, sizeof(stream));
+ ret = inflateInit2(&stream, (15 + 16));
+ if (ret != Z_OK)
+ die("cannot start zlib inflater, zlib err %d", ret);
+
+ 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 = 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:
+ inflateEnd(&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");
+ char *env[3];
+ struct strbuf buf = STRBUF_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)";
+
+ memset(&env, 0, sizeof(env));
+ strbuf_addf(&buf, "GIT_COMMITTER_NAME=%s", user);
+ env[0] = strbuf_detach(&buf, NULL);
+
+ strbuf_addf(&buf, "GIT_COMMITTER_EMAIL=%s@http.%s", user, host);
+ env[1] = strbuf_detach(&buf, NULL);
+ env[2] = NULL;
+
+ memset(&cld, 0, sizeof(cld));
+ cld.argv = argv;
+ cld.env = (const char *const *)env;
+ 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);
+ free(env[0]);
+ free(env[1]);
+ strbuf_release(&buf);
+}
+
+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)
+{
+ char buffer[1000];
+
+ http_status(500, "Internal Server Error");
+ hdr_nocache();
+ end_headers();
+
+ vsnprintf(buffer, sizeof(buffer), err, params);
+ fprintf(stderr, "fatal: %s\n", buffer);
+ exit(0);
+}
+
+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);
+ strbuf_addstr(&buf, root);
+ if (buf.buf[buf.len - 1] != '/')
+ strbuf_addch(&buf, '/');
+ 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_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);
+
+ git_config(http_config, NULL);
+ cmd->imp(cmd_arg);
+ return 0;
+}