diff options
| -rw-r--r-- | Documentation/git-http-backend.txt | 39 | ||||
| -rw-r--r-- | http-backend.c | 324 |
2 files changed, 359 insertions, 4 deletions
diff --git a/Documentation/git-http-backend.txt b/Documentation/git-http-backend.txt index 867675fcec..022a2433a8 100644 --- a/Documentation/git-http-backend.txt +++ b/Documentation/git-http-backend.txt @@ -22,6 +22,23 @@ By default, only the `upload-pack` service is enabled, which serves This is ideally suited for read-only updates, i.e., pulling from git repositories. +SERVICES +-------- +These services can be enabled/disabled using the per-repository +configuration file: + +http.uploadpack:: + This serves 'git-fetch-pack' and 'git-ls-remote' clients. + It is enabled by default, but a repository can disable it + by setting this configuration item to `false`. + +http.receivepack:: + This serves 'git-send-pack' clients, allowing push. It is + disabled by default for anonymous users, and enabled by + default for users authenticated by the web server. It can be + disabled by setting this item to `false`, or enabled for all + users, including anonymous users, by setting it to `true`. + URL TRANSLATION --------------- 'git-http-backend' relies on the invoking web server to perform @@ -49,7 +66,19 @@ ScriptAlias /git/ /usr/libexec/git-core/git-http-backend/git/ </Files> ---------------------------------------------------------------- + -To require authentication for reads, use a Directory +To enable anonymous read access but authenticated write access, +require authorization with a LocationMatch directive: ++ +---------------------------------------------------------------- +<LocationMatch ".*/git-receive-pack$"> + AuthType Basic + AuthName "Git Access" + Require group committers + ... +</LocationMatch> +---------------------------------------------------------------- ++ +To require authentication for both reads and writes, use a Directory directive around the repository, or one of its parent directories: + ---------------------------------------------------------------- @@ -92,6 +121,14 @@ by the invoking web server, including: * QUERY_STRING * REQUEST_METHOD +The backend process sets GIT_COMMITTER_NAME to '$REMOTE_USER' and +GIT_COMMITTER_EMAIL to '$\{REMOTE_USER}@http.$\{REMOTE_ADDR\}', +ensuring that any reflogs created by 'git-receive-pack' contain some +identifying information of the remote user who performed the push. + +All CGI environment variables are available to each of the hooks +invoked by the 'git-receive-pack'. + Author ------ Written by Shawn O. Pearce <spearce@spearce.org>. diff --git a/http-backend.c b/http-backend.c index 22bec56b98..bfce52063f 100644 --- a/http-backend.c +++ b/http-backend.c @@ -4,11 +4,109 @@ #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 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; +} + static void format_write(int fd, const char *fmt, ...) { static char buffer[1024]; @@ -81,6 +179,21 @@ static NORETURN void not_found(const char *err, ...) exit(0); } +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 send_strbuf(const char *type, struct strbuf *buf) { hdr_int(content_length, buf->len); @@ -147,6 +260,145 @@ static void get_idx_file(char *name) send_file("application/x-git-packed-objects-toc", name); } +static int http_config(const char *var, const char *value, void *cb) +{ + struct rpc_service *svc = cb; + + if (!prefixcmp(var, "http.") && + !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); + + git_config(http_config, svc); + 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) { @@ -167,11 +419,32 @@ static int show_text_ref(const char *name, const unsigned char *sha1, static void get_info_refs(char *arg) { + const char *service_name = get_parameter("service"); struct strbuf buf = STRBUF_INIT; - for_each_ref(show_text_ref, &buf); hdr_nocache(); - send_strbuf("text/plain", &buf); + + 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 { + for_each_ref(show_text_ref, &buf); + send_strbuf("text/plain", &buf); + } strbuf_release(&buf); } @@ -200,6 +473,48 @@ static void get_info_packs(char *arg) 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]; @@ -225,7 +540,10 @@ static struct service_cmd { {"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} + {"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) |