staload "prelude/DATS/array.dats" %{^ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include char uri_root[512]; static const struct table_entry { const char *extension; const char *content_type; } content_type_table[] = { { "txt", "text/plain" }, { "c", "text/plain" }, { "h", "text/plain" }, { "html", "text/html" }, { "htm", "text/htm" }, { "css", "text/css" }, { "gif", "image/gif" }, { "jpg", "image/jpeg" }, { "jpeg", "image/jpeg" }, { "png", "image/png" }, { "pdf", "application/pdf" }, { "ps", "application/postsript" }, { NULL, NULL }, }; void syntax(void); int http_server(char* docroot); %} %{ /* Try to guess a good content-type for 'path' */ static const char * guess_content_type(const char *path) { const char *last_period, *extension; const struct table_entry *ent; last_period = strrchr(path, '.'); if (!last_period || strchr(last_period, '/')) goto not_found; /* no exension */ extension = last_period + 1; for (ent = &content_type_table[0]; ent->extension; ++ent) { if (!evutil_ascii_strcasecmp(ent->extension, extension)) return ent->content_type; } not_found: return "application/misc"; } /* Callback used for the /dump URI, and for every non-GET request: * dumps all information to stdout and gives back a trivial 200 ok */ static void dump_request_cb(struct evhttp_request *req, void *arg) { const char *cmdtype; struct evkeyvalq *headers; struct evkeyval *header; struct evbuffer *buf; switch (evhttp_request_get_command(req)) { case EVHTTP_REQ_GET: cmdtype = "GET"; break; case EVHTTP_REQ_POST: cmdtype = "POST"; break; case EVHTTP_REQ_HEAD: cmdtype = "HEAD"; break; case EVHTTP_REQ_PUT: cmdtype = "PUT"; break; case EVHTTP_REQ_DELETE: cmdtype = "DELETE"; break; case EVHTTP_REQ_OPTIONS: cmdtype = "OPTIONS"; break; case EVHTTP_REQ_TRACE: cmdtype = "TRACE"; break; case EVHTTP_REQ_CONNECT: cmdtype = "CONNECT"; break; case EVHTTP_REQ_PATCH: cmdtype = "PATCH"; break; default: cmdtype = "unknown"; break; } printf("Received a %s request for %s\nHeaders:\n", cmdtype, evhttp_request_get_uri(req)); headers = evhttp_request_get_input_headers(req); for (header = headers->tqh_first; header; header = header->next.tqe_next) { printf(" %s: %s\n", header->key, header->value); } buf = evhttp_request_get_input_buffer(req); puts("Input data: <<<"); while (evbuffer_get_length(buf)) { int n; char cbuf[128]; n = evbuffer_remove(buf, cbuf, sizeof(buf)-1); fwrite(cbuf, 1, n, stdout); } puts(">>>"); evhttp_send_reply(req, 200, "OK", NULL); } /* This callback gets invoked when we get any http request that doesn't match * any other callback. Like any evhttp server callback, it has a simple job: * it must eventually call evhttp_send_error() or evhttp_send_reply(). */ static void send_document_cb(struct evhttp_request *req, void *arg) { struct evbuffer *evb = NULL; const char *docroot = arg; const char *uri = evhttp_request_get_uri(req); struct evhttp_uri *decoded = NULL; const char *path; char *decoded_path; char *whole_path = NULL; size_t len; int fd = -1; struct stat st; if (evhttp_request_get_command(req) != EVHTTP_REQ_GET) { dump_request_cb(req, arg); return; } printf("Got a GET request for <%s>\n", uri); /* Decode the URI */ decoded = evhttp_uri_parse(uri); if (!decoded) { printf("It's not a good URI. Sending BADREQUEST\n"); evhttp_send_error(req, HTTP_BADREQUEST, 0); return; } /* Let's see what path the user asked for. */ path = evhttp_uri_get_path(decoded); if (!path) path = "/"; /* We need to decode it, to see what path the user really wanted. */ decoded_path = evhttp_uridecode(path, 0, NULL); /* Don't allow any ".."s in the path, to avoid exposing stuff outside * of the docroot. This test is both overzealous and underzealous: * it forbids aceptable paths like "/this/one..here", but it doesn't * do anything to prevent symlink following." */ if (strstr(decoded_path, "..")) goto err; len = strlen(decoded_path)+strlen(docroot)+2; if (!(whole_path = malloc(len))) { perror("malloc"); goto err; } evutil_snprintf(whole_path, len, "%s/%s", docroot, decoded_path); if (stat(whole_path, &st)<0) { goto err; } /* This holds the content we're sending. */ evb = evbuffer_new(); if (S_ISDIR(st.st_mode)) { /* If it's a directory, read the comments and make a little * index page */ DIR *d; struct dirent *ent; const char *trailing_slash = ""; if (!strlen(path) || path[strlen(path)-1] != '/') trailing_slash = "/"; if (!(d = opendir(whole_path))) goto err; evbuffer_add_printf(evb, "\n \n" " %s\n" " \n" " \n" " \n" "

%s

\n" "
    \n", decoded_path, /* XXX html-escape this. */ uri_root, path, /* XXX html-escape this? */ trailing_slash, decoded_path /* XXX html-escape this */); while ((ent = readdir(d))) { const char *name = ent->d_name; evbuffer_add_printf(evb, "
  • %s\n", name, name);/* XXX escape this */ } evbuffer_add_printf(evb, "
\n"); closedir(d); evhttp_add_header(evhttp_request_get_output_headers(req), "Content-Type", "text/html"); } else { /* Otherwise it's a file; add it to the buffer to get * sent via sendfile */ const char *type = guess_content_type(decoded_path); if ((fd = open(whole_path, O_RDONLY)) < 0) { perror("open"); goto err; } if (fstat(fd, &st)<0) { /* Make sure the length still matches, now that we * opened the file :/ */ perror("fstat"); goto err; } evhttp_add_header(evhttp_request_get_output_headers(req), "Content-Type", type); evbuffer_add_file(evb, fd, 0, st.st_size); } evhttp_send_reply(req, 200, "OK", evb); goto done; err: evhttp_send_error(req, 404, "Document was not found"); if (fd>=0) close(fd); done: if (decoded) evhttp_uri_free(decoded); if (decoded_path) free(decoded_path); if (whole_path) free(whole_path); if (evb) evbuffer_free(evb); } void syntax(void) { fprintf(stdout, "Syntax: http-server \n"); } int http_server(char* docroot) { struct event_base *base; struct evhttp *http; struct evhttp_bound_socket *handle; if (signal(SIGPIPE, SIG_IGN) == SIG_ERR) return (1); base = event_base_new(); if (!base) { fprintf(stderr, "Couldn't create an event_base: exiting\n"); return 1; } /* Create a new evhttp object to handle requests. */ http = evhttp_new(base); if (!http) { fprintf(stderr, "couldn't create evhttp. Exiting.\n"); return 1; } /* The /dump URI will dump all requests to stdout and say 200 ok. */ evhttp_set_cb(http, "/dump", dump_request_cb, NULL); /* We want to accept arbitrary requests, so we need to set a "generic" * cb. We can also add callbacks for specific paths. */ evhttp_set_gencb(http, send_document_cb, docroot); /* Now we tell the evhttp what port to listen on */ handle = evhttp_bind_socket_with_handle(http, "0.0.0.0", 8080); if (!handle) { fprintf(stderr, "couldn't bind to port 8080. Exiting.\n"); return 1; } event_base_dispatch(base); return 0; } %} extern fun syntax():void = "mac#syntax" extern fun http_server(docroot: string):int = "mac#http_server" exception Error of () implement main(argc, argv) = if argc < 2 then syntax() else if http_server(argv[1]) = 0 then () else $raise Error ()