diff options
Diffstat (limited to 'http-backend.c')
| -rw-r--r-- | http-backend.c | 713 |
1 files changed, 713 insertions, 0 deletions
diff --git a/http-backend.c b/http-backend.c new file mode 100644 index 0000000000..f3dc218b2a --- /dev/null +++ b/http-backend.c @@ -0,0 +1,713 @@ +#include "cache.h" +#include "config.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" +#include "packfile.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 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, 1 }, + { "receive-pack", "receivepack", 0, -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(struct strbuf *hdr, unsigned code, const char *msg) +{ + strbuf_addf(hdr, "Status: %u %s\r\n", code, msg); +} + +static void hdr_str(struct strbuf *hdr, const char *name, const char *value) +{ + strbuf_addf(hdr, "%s: %s\r\n", name, value); +} + +static void hdr_int(struct strbuf *hdr, const char *name, uintmax_t value) +{ + strbuf_addf(hdr, "%s: %" PRIuMAX "\r\n", name, value); +} + +static void hdr_date(struct strbuf *hdr, const char *name, timestamp_t when) +{ + const char *value = show_date(when, 0, DATE_MODE(RFC2822)); + hdr_str(hdr, name, value); +} + +static void hdr_nocache(struct strbuf *hdr) +{ + hdr_str(hdr, "Expires", "Fri, 01 Jan 1980 00:00:00 GMT"); + hdr_str(hdr, "Pragma", "no-cache"); + hdr_str(hdr, "Cache-Control", "no-cache, max-age=0, must-revalidate"); +} + +static void hdr_cache_forever(struct strbuf *hdr) +{ + timestamp_t now = time(NULL); + hdr_date(hdr, "Date", now); + hdr_date(hdr, "Expires", now + 31536000); + hdr_str(hdr, "Cache-Control", "public, max-age=31536000"); +} + +static void end_headers(struct strbuf *hdr) +{ + strbuf_add(hdr, "\r\n", 2); + write_or_die(1, hdr->buf, hdr->len); + strbuf_release(hdr); +} + +__attribute__((format (printf, 2, 3))) +static NORETURN void not_found(struct strbuf *hdr, const char *err, ...) +{ + va_list params; + + http_status(hdr, 404, "Not Found"); + hdr_nocache(hdr); + end_headers(hdr); + + va_start(params, err); + if (err && *err) + vfprintf(stderr, err, params); + va_end(params); + exit(0); +} + +__attribute__((format (printf, 2, 3))) +static NORETURN void forbidden(struct strbuf *hdr, const char *err, ...) +{ + va_list params; + + http_status(hdr, 403, "Forbidden"); + hdr_nocache(hdr); + end_headers(hdr); + + va_start(params, err); + if (err && *err) + vfprintf(stderr, err, params); + va_end(params); + exit(0); +} + +static void select_getanyfile(struct strbuf *hdr) +{ + if (!getanyfile) + forbidden(hdr, "Unsupported service: getanyfile"); +} + +static void send_strbuf(struct strbuf *hdr, + const char *type, struct strbuf *buf) +{ + hdr_int(hdr, content_length, buf->len); + hdr_str(hdr, content_type, type); + end_headers(hdr); + write_or_die(1, buf->buf, buf->len); +} + +static void send_local_file(struct strbuf *hdr, const char *the_type, + const char *name) +{ + char *p = git_pathdup("%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(hdr, "Cannot open '%s': %s", p, strerror(errno)); + if (fstat(fd, &sb) < 0) + die_errno("Cannot stat '%s'", p); + + hdr_int(hdr, content_length, sb.st_size); + hdr_str(hdr, content_type, the_type); + hdr_date(hdr, last_modified, sb.st_mtime); + end_headers(hdr); + + 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); + free(p); +} + +static void get_text_file(struct strbuf *hdr, char *name) +{ + select_getanyfile(hdr); + hdr_nocache(hdr); + send_local_file(hdr, "text/plain", name); +} + +static void get_loose_object(struct strbuf *hdr, char *name) +{ + select_getanyfile(hdr); + hdr_cache_forever(hdr); + send_local_file(hdr, "application/x-git-loose-object", name); +} + +static void get_pack_file(struct strbuf *hdr, char *name) +{ + select_getanyfile(hdr); + hdr_cache_forever(hdr); + send_local_file(hdr, "application/x-git-packed-objects", name); +} + +static void get_idx_file(struct strbuf *hdr, char *name) +{ + select_getanyfile(hdr); + hdr_cache_forever(hdr); + send_local_file(hdr, "application/x-git-packed-objects-toc", name); +} + +static void http_config(void) +{ + int i, value = 0; + 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]; + strbuf_addf(&var, "http.%s", svc->config_name); + if (!git_config_get_bool(var.buf, &value)) + svc->enabled = value; + strbuf_reset(&var); + } + + strbuf_release(&var); +} + +static struct rpc_service *select_service(struct strbuf *hdr, const char *name) +{ + const char *svc_name; + struct rpc_service *svc = NULL; + int i; + + if (!skip_prefix(name, "git-", &svc_name)) + forbidden(hdr, "Unsupported service: '%s'", name); + + for (i = 0; i < ARRAY_SIZE(rpc_service); i++) { + struct rpc_service *s = &rpc_service[i]; + if (!strcmp(s->name, svc_name)) { + svc = s; + break; + } + } + + if (!svc) + forbidden(hdr, "Unsupported service: '%s'", name); + + if (svc->enabled < 0) { + const char *user = getenv("REMOTE_USER"); + svc->enabled = (user && *user) ? 1 : 0; + } + if (!svc->enabled) + forbidden(hdr, "Service not enabled: '%s'", svc->name); + return svc; +} + +/* + * 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; + + memset(&stream, 0, sizeof(stream)); + git_inflate_init_gzip_only(&stream); + + while (1) { + 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.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) < 0) + die("%s aborted reading request", prog_name); + cnt += n; + + if (ret == Z_STREAM_END) + goto done; + } + } + +done: + git_inflate_end(&stream); + close(out); + free(full_request); +} + +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) < 0) + 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"); + const char *host = getenv("REMOTE_ADDR"); + int gzipped_request = 0; + struct child_process cld = CHILD_PROCESS_INIT; + + 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(&cld.env_array, "GIT_COMMITTER_NAME=%s", user); + if (!getenv("GIT_COMMITTER_EMAIL")) + argv_array_pushf(&cld.env_array, + "GIT_COMMITTER_EMAIL=%s@http.%s", user, host); + + cld.argv = argv; + if (buffer_input || 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, buffer_input); + else if (buffer_input) + copy_request(argv[0], cld.in); + else + close(0); + + if (finish_command(&cld)) + exit(1); +} + +static int show_text_ref(const char *name, const struct object_id *oid, + int flag, void *cb_data) +{ + const char *name_nons = strip_namespace(name); + struct strbuf *buf = cb_data; + struct object *o = parse_object(oid); + if (!o) + return 0; + + strbuf_addf(buf, "%s\t%s\n", oid_to_hex(oid), name_nons); + if (o->type == OBJ_TAG) { + o = deref_tag(o, name, 0); + if (!o) + return 0; + strbuf_addf(buf, "%s\t%s^{}\n", oid_to_hex(&o->oid), + name_nons); + } + return 0; +} + +static void get_info_refs(struct strbuf *hdr, char *arg) +{ + const char *service_name = get_parameter("service"); + struct strbuf buf = STRBUF_INIT; + + hdr_nocache(hdr); + + if (service_name) { + const char *argv[] = {NULL /* service name */, + "--stateless-rpc", "--advertise-refs", + ".", NULL}; + struct rpc_service *svc = select_service(hdr, service_name); + + strbuf_addf(&buf, "application/x-git-%s-advertisement", + svc->name); + hdr_str(hdr, content_type, buf.buf); + end_headers(hdr); + + packet_write_fmt(1, "# service=git-%s\n", svc->name); + packet_flush(1); + + argv[0] = svc->name; + run_service(argv, 0); + + } else { + select_getanyfile(hdr); + for_each_namespaced_ref(show_text_ref, &buf); + send_strbuf(hdr, "text/plain", &buf); + } + strbuf_release(&buf); +} + +static int show_head_ref(const char *refname, const struct object_id *oid, + int flag, void *cb_data) +{ + struct strbuf *buf = cb_data; + + if (flag & REF_ISSYMREF) { + const char *target = resolve_ref_unsafe(refname, + RESOLVE_REF_READING, + NULL, NULL); + + if (target) + strbuf_addf(buf, "ref: %s\n", strip_namespace(target)); + } else { + strbuf_addf(buf, "%s\n", oid_to_hex(oid)); + } + + return 0; +} + +static void get_head(struct strbuf *hdr, char *arg) +{ + struct strbuf buf = STRBUF_INIT; + + select_getanyfile(hdr); + head_ref_namespaced(show_head_ref, &buf); + send_strbuf(hdr, "text/plain", &buf); + strbuf_release(&buf); +} + +static void get_info_packs(struct strbuf *hdr, char *arg) +{ + size_t objdirlen = strlen(get_object_directory()); + struct strbuf buf = STRBUF_INIT; + struct packed_git *p; + size_t cnt = 0; + + select_getanyfile(hdr); + 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(hdr); + send_strbuf(hdr, "text/plain; charset=utf-8", &buf); + strbuf_release(&buf); +} + +static void check_content_type(struct strbuf *hdr, const char *accepted_type) +{ + const char *actual_type = getenv("CONTENT_TYPE"); + + if (!actual_type) + actual_type = ""; + + if (strcmp(actual_type, accepted_type)) { + http_status(hdr, 415, "Unsupported Media Type"); + hdr_nocache(hdr); + end_headers(hdr); + format_write(1, + "Expected POST with Content-Type '%s'," + " but received '%s' instead.\n", + accepted_type, actual_type); + exit(0); + } +} + +static void service_rpc(struct strbuf *hdr, char *service_name) +{ + const char *argv[] = {NULL, "--stateless-rpc", ".", NULL}; + struct rpc_service *svc = select_service(hdr, service_name); + struct strbuf buf = STRBUF_INIT; + + strbuf_reset(&buf); + strbuf_addf(&buf, "application/x-git-%s-request", svc->name); + check_content_type(hdr, buf.buf); + + hdr_nocache(hdr); + + strbuf_reset(&buf); + strbuf_addf(&buf, "application/x-git-%s-result", svc->name); + hdr_str(hdr, content_type, buf.buf); + + end_headers(hdr); + + argv[0] = svc->name; + run_service(argv, svc->buffer_input); + strbuf_release(&buf); +} + +static int dead; +static NORETURN void die_webcgi(const char *err, va_list params) +{ + if (dead <= 1) { + struct strbuf hdr = STRBUF_INIT; + + vreportf("fatal: ", err, params); + + http_status(&hdr, 500, "Internal Server Error"); + hdr_nocache(&hdr); + end_headers(&hdr); + } + 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; + 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)(struct strbuf *, char *); +} services[] = { + {"GET", "/HEAD$", get_head}, + {"GET", "/info/refs$", 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} +}; + +static int bad_request(struct strbuf *hdr, const struct service_cmd *c) +{ + const char *proto = getenv("SERVER_PROTOCOL"); + + if (proto && !strcmp(proto, "HTTP/1.1")) { + http_status(hdr, 405, "Method Not Allowed"); + hdr_str(hdr, "Allow", + !strcmp(c->method, "GET") ? "GET, HEAD" : c->method); + } else + http_status(hdr, 400, "Bad Request"); + hdr_nocache(hdr); + end_headers(hdr); + return 0; +} + +int cmd_main(int argc, const char **argv) +{ + char *method = getenv("REQUEST_METHOD"); + char *dir; + struct service_cmd *cmd = NULL; + char *cmd_arg = NULL; + int i; + struct strbuf hdr = STRBUF_INIT; + + set_die_routine(die_webcgi); + set_die_is_recursing_routine(die_webcgi_recursing); + + 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)) + return bad_request(&hdr, c); + + cmd = c; + n = out[0].rm_eo - out[0].rm_so; + cmd_arg = xmemdupz(dir + out[0].rm_so + 1, n - 1); + dir[out[0].rm_so] = 0; + break; + } + regfree(&re); + } + + if (!cmd) + not_found(&hdr, "Request not supported: '%s'", dir); + + setup_path(); + if (!enter_repo(dir, 0)) + not_found(&hdr, "Not a git repository: '%s'", dir); + if (!getenv("GIT_HTTP_EXPORT_ALL") && + access("git-daemon-export-ok", F_OK) ) + not_found(&hdr, "Repository not exported: '%s'", dir); + + http_config(); + max_request_buffer = git_env_ulong("GIT_HTTP_MAX_REQUEST_BUFFER", + max_request_buffer); + + cmd->imp(&hdr, cmd_arg); + return 0; +} |