ucode.c

   1 /*
   2  * uhttpd - Tiny single-threaded httpd
   3  *
   4  *   Copyright (C) 2010-2013 Jo-Philipp Wich <xm@subsignal.org>
   5  *   Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
   6  *
   7  * Permission to use, copy, modify, and/or distribute this software for any
   8  * purpose with or without fee is hereby granted, provided that the above
   9  * copyright notice and this permission notice appear in all copies.
  10  *
  11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  18  */
  19
  20 #include <libubox/blobmsg.h>
  21 #include <ucode/compiler.h>
  22 #include <ucode/lib.h>
  23 #include <ucode/vm.h>
  24 #include <stdio.h>
  25 #include <poll.h>
  26
  27 #include "uhttpd.h"
  28 #include "plugin.h"
  29
  30 #define UH_UCODE_CB     "handle_request"
  31
  32 static const struct uhttpd_ops *ops;
  33 static struct config *_conf;
  34 #define conf (*_conf)
  35
  36 static struct ucode_prefix *current_prefix;
  37
  38 static uc_value_t *
  39 uh_ucode_recv(uc_vm_t *vm, size_t nargs)
  40 {
  41         static struct pollfd pfd = { .fd = STDIN_FILENO, .events = POLLIN };
  42         int data_len = 0, len = BUFSIZ, rlen, r;
  43         uc_value_t *v = uc_fn_arg(0);
  44         uc_stringbuf_t *buf;
  45
  46         if (ucv_type(v) == UC_INTEGER) {
  47                 len = ucv_int64_get(v);
  48         }
  49         else if (v != NULL) {
  50                 uc_vm_raise_exception(vm, EXCEPTION_TYPE, "Argument not an integer");
  51
  52                 return NULL;
  53         }
  54
  55         buf = ucv_stringbuf_new();
  56
  57         while (len > 0) {
  58                 rlen = (len < BUFSIZ) ? len : BUFSIZ;
  59
  60                 if (printbuf_memset(buf, -1, 0, rlen)) {
  61                         uc_vm_raise_exception(vm, EXCEPTION_RUNTIME, "Out of memory");
  62                         printbuf_free(buf);
  63
  64                         return NULL;
  65                 }
  66
  67                 buf->bpos -= rlen;
  68                 r = read(STDIN_FILENO, buf->buf + buf->bpos, rlen);
  69
  70                 if (r < 0) {
  71                         if (errno == EWOULDBLOCK || errno == EAGAIN) {
  72                                 pfd.revents = 0;
  73                                 poll(&pfd, 1, 1000);
  74
  75                                 if (pfd.revents & POLLIN)
  76                                         continue;
  77                         }
  78
  79                         if (errno == EINTR)
  80                                 continue;
  81
  82                         if (!data_len)
  83                                 data_len = -1;
  84
  85                         break;
  86                 }
  87
  88                 buf->bpos += r;
  89                 data_len += r;
  90                 len -= r;
  91
  92                 if (r != rlen)
  93                         break;
  94         }
  95
  96         if (data_len > 0) {
  97                 /* add final guard \0 but do not count it */
  98                 if (printbuf_memset(buf, -1, 0, 1)) {
  99                         uc_vm_raise_exception(vm, EXCEPTION_RUNTIME, "Out of memory");
 100                         printbuf_free(buf);
 101
 102                         return NULL;
 103                 }
 104
 105                 buf->bpos--;
 106
 107                 return ucv_stringbuf_finish(buf);
 108         }
 109
 110         printbuf_free(buf);
 111
 112         return NULL;
 113 }
 114
 115 static uc_value_t *
 116 uh_ucode_send(uc_vm_t *vm, size_t nargs)
 117 {
 118         uc_value_t *val = uc_fn_arg(0);
 119         ssize_t len;
 120         char *p;
 121
 122         if (ucv_type(val) == UC_STRING) {
 123                 len = write(STDOUT_FILENO, ucv_string_get(val), ucv_string_length(val));
 124         }
 125         else if (val != NULL) {
 126                 p = ucv_to_string(vm, val);
 127                 len = p ? write(STDOUT_FILENO, p, strlen(p)) : 0;
 128                 free(p);
 129         }
 130         else {
 131                 len = 0;
 132         }
 133
 134         return ucv_int64_new(len);
 135 }
 136
 137 static uc_value_t *
 138 uh_ucode_strconvert(uc_vm_t *vm, size_t nargs, int (*convert)(char *, int, const char *, int))
 139 {
 140         uc_value_t *val = uc_fn_arg(0);
 141         static char out_buf[4096];
 142         int out_len;
 143         char *p;
 144
 145         if (ucv_type(val) == UC_STRING) {
 146                 out_len = convert(out_buf, sizeof(out_buf),
 147                         ucv_string_get(val), ucv_string_length(val));
 148         }
 149         else if (val != NULL) {
 150                 p = ucv_to_string(vm, val);
 151                 out_len = p ? convert(out_buf, sizeof(out_buf), p, strlen(p)) : 0;
 152                 free(p);
 153         }
 154         else {
 155                 out_len = 0;
 156         }
 157
 158         if (out_len < 0) {
 159                 const char *error;
 160
 161                 if (out_len == -1)
 162                         error = "buffer overflow";
 163                 else
 164                         error = "malformed string";
 165
 166                 uc_vm_raise_exception(vm, EXCEPTION_RUNTIME,
 167                         "%s on URL conversion\n", error);
 168
 169                 return NULL;
 170         }
 171
 172         return ucv_string_new_length(out_buf, out_len);
 173 }
 174
 175 static uc_value_t *
 176 uh_ucode_urldecode(uc_vm_t *vm, size_t nargs)
 177 {
 178         return uh_ucode_strconvert(vm, nargs, ops->urldecode);
 179 }
 180
 181 static uc_value_t *
 182 uh_ucode_urlencode(uc_vm_t *vm, size_t nargs)
 183 {
 184         return uh_ucode_strconvert(vm, nargs, ops->urlencode);
 185 }
 186
 187 static uc_parse_config_t config = {
 188         .strict_declarations = false,
 189         .lstrip_blocks = true,
 190         .trim_blocks = true
 191 };
 192
 193 static void
 194 uh_ucode_exception(uc_vm_t *vm, uc_exception_t *ex)
 195 {
 196         uc_value_t *ctx;
 197
 198         if (ex->type == EXCEPTION_EXIT)
 199                 return;
 200
 201         printf("Status: 500 Internal Server Error\r\n\r\n"
 202                "Exception while executing ucode program %s:\n",
 203                current_prefix->handler);
 204
 205         switch (ex->type) {
 206         case EXCEPTION_SYNTAX:    printf("Syntax error");    break;
 207         case EXCEPTION_RUNTIME:   printf("Runtime error");   break;
 208         case EXCEPTION_TYPE:      printf("Type error");      break;
 209         case EXCEPTION_REFERENCE: printf("Reference error"); break;
 210         default:                  printf("Error");
 211         }
 212
 213         printf(": %s\n", ex->message);
 214
 215         ctx = ucv_object_get(ucv_array_get(ex->stacktrace, 0), "context", NULL);
 216
 217         if (ctx)
 218                 printf("%s\n", ucv_string_get(ctx));
 219 }
 220
 221 static void
 222 uh_ucode_state_init(struct ucode_prefix *ucode)
 223 {
 224         char *syntax_error = NULL;
 225         uc_vm_t *vm = &ucode->ctx;
 226         uc_program_t *handler;
 227         uc_vm_status_t status;
 228         uc_source_t *src;
 229         uc_value_t *v;
 230         int exitcode;
 231
 232         uc_vm_init(vm, &config);
 233         uc_stdlib_load(uc_vm_scope_get(vm));
 234
 235         /* build uhttpd api table */
 236         v = ucv_object_new(vm);
 237
 238         ucv_object_add(v, "send", ucv_cfunction_new("send", uh_ucode_send));
 239         ucv_object_add(v, "sendc", ucv_get(ucv_object_get(v, "send", NULL)));
 240         ucv_object_add(v, "recv", ucv_cfunction_new("recv", uh_ucode_recv));
 241         ucv_object_add(v, "urldecode", ucv_cfunction_new("urldecode", uh_ucode_urldecode));
 242         ucv_object_add(v, "urlencode", ucv_cfunction_new("urlencode", uh_ucode_urlencode));
 243         ucv_object_add(v, "docroot", ucv_string_new(conf.docroot));
 244
 245         ucv_object_add(uc_vm_scope_get(vm), "uhttpd", v);
 246
 247         src = uc_source_new_file(ucode->handler);
 248
 249         if (!src) {
 250                 fprintf(stderr, "Error: Unable to open ucode handler: %s\n",
 251                         strerror(errno));
 252
 253                 exit(1);
 254         }
 255
 256         handler = uc_compile(&config, src, &syntax_error);
 257
 258         uc_source_put(src);
 259
 260         if (!handler) {
 261                 fprintf(stderr, "Error: Unable to compile ucode handler: %s\n",
 262                         syntax_error);
 263
 264                 exit(1);
 265         }
 266
 267         free(syntax_error);
 268
 269         vm->output = fopen("/dev/null", "w");
 270
 271         if (!vm->output) {
 272                 fprintf(stderr, "Error: Unable to open /dev/null for writing: %s\n",
 273                         strerror(errno));
 274
 275                 exit(1);
 276         }
 277
 278         status = uc_vm_execute(vm, handler, &v);
 279         exitcode = (int)ucv_int64_get(v);
 280
 281         uc_program_put(handler);
 282         ucv_put(v);
 283
 284         switch (status) {
 285         case STATUS_OK:
 286                 break;
 287
 288         case STATUS_EXIT:
 289                 fprintf(stderr, "Error: The ucode handler invoked exit(%d)\n", exitcode);
 290                 exit(exitcode ? exitcode : 1);
 291
 292         case ERROR_COMPILE:
 293                 fprintf(stderr, "Error: Compilation error while executing ucode handler\n");
 294                 exit(1);
 295
 296         case ERROR_RUNTIME:
 297                 fprintf(stderr, "Error: Runtime error while executing ucode handler\n");
 298                 exit(2);
 299         }
 300
 301         v = ucv_object_get(uc_vm_scope_get(vm), UH_UCODE_CB, NULL);
 302
 303         if (!ucv_is_callable(v)) {
 304                 fprintf(stderr, "Error: The ucode handler declares no " UH_UCODE_CB "() callback.\n");
 305                 exit(1);
 306         }
 307
 308         uc_vm_exception_handler_set(vm, uh_ucode_exception);
 309
 310         ucv_gc(vm);
 311
 312         fclose(vm->output);
 313
 314         vm->output = stdout;
 315 }
 316
 317 static void
 318 ucode_main(struct client *cl, struct path_info *pi, char *url)
 319 {
 320         uc_vm_t *vm = &current_prefix->ctx;
 321         uc_value_t *req, *hdr, *res;
 322         int path_len, prefix_len;
 323         struct blob_attr *cur;
 324         struct env_var *var;
 325         char *str;
 326         int rem;
 327
 328         /* new env table for this request */
 329         req = ucv_object_new(vm);
 330
 331         prefix_len = strlen(pi->name);
 332         path_len = strlen(url);
 333         str = strchr(url, '?');
 334
 335         if (str) {
 336                 if (*(str + 1))
 337                         pi->query = str + 1;
 338
 339                 path_len = str - url;
 340         }
 341
 342         if (prefix_len > 0 && pi->name[prefix_len - 1] == '/')
 343                 prefix_len--;
 344
 345         if (path_len > prefix_len) {
 346                 ucv_object_add(req, "PATH_INFO",
 347                         ucv_string_new_length(url + prefix_len, path_len - prefix_len));
 348         }
 349
 350         for (var = ops->get_process_vars(cl, pi); var->name; var++) {
 351                 if (!var->value)
 352                         continue;
 353
 354                 ucv_object_add(req, var->name, ucv_string_new(var->value));
 355         }
 356
 357         ucv_object_add(req, "HTTP_VERSION",
 358                 ucv_double_new(0.9 + (cl->request.version / 10.0)));
 359
 360         hdr = ucv_object_new(vm);
 361
 362         blob_for_each_attr(cur, cl->hdr.head, rem)
 363                 ucv_object_add(hdr, blobmsg_name(cur), ucv_string_new(blobmsg_data(cur)));
 364
 365         ucv_object_add(req, "headers", hdr);
 366
 367         res = uc_vm_invoke(vm, UH_UCODE_CB, 1, req);
 368
 369         ucv_put(req);
 370         ucv_put(res);
 371
 372         exit(0);
 373 }
 374
 375 static void
 376 ucode_handle_request(struct client *cl, char *url, struct path_info *pi)
 377 {
 378         struct ucode_prefix *p;
 379         static struct path_info _pi;
 380
 381         list_for_each_entry(p, &conf.ucode_prefix, list) {
 382                 if (!ops->path_match(p->prefix, url))
 383                         continue;
 384
 385                 pi = &_pi;
 386                 pi->name = p->prefix;
 387                 pi->phys = p->handler;
 388
 389                 current_prefix = p;
 390
 391                 if (!ops->create_process(cl, pi, url, ucode_main)) {
 392                         ops->client_error(cl, 500, "Internal Server Error",
 393                                           "Failed to create CGI process: %s",
 394                                           strerror(errno));
 395                 }
 396
 397                 return;
 398         }
 399
 400         ops->client_error(cl, 500, "Internal Server Error",
 401                           "Failed to lookup matching handler");
 402 }
 403
 404 static bool
 405 check_ucode_url(const char *url)
 406 {
 407         struct ucode_prefix *p;
 408
 409         list_for_each_entry(p, &conf.ucode_prefix, list)
 410                 if (ops->path_match(p->prefix, url))
 411                         return true;
 412
 413         return false;
 414 }
 415
 416 static struct dispatch_handler ucode_dispatch = {
 417         .script = true,
 418         .check_url = check_ucode_url,
 419         .handle_request = ucode_handle_request,
 420 };
 421
 422 static int
 423 ucode_plugin_init(const struct uhttpd_ops *o, struct config *c)
 424 {
 425         struct ucode_prefix *p;
 426
 427         ops = o;
 428         _conf = c;
 429
 430         list_for_each_entry(p, &conf.ucode_prefix, list)
 431                 uh_ucode_state_init(p);
 432
 433         ops->dispatch_add(&ucode_dispatch);
 434         return 0;
 435 }
 436
 437 struct uhttpd_plugin uhttpd_plugin = {
 438         .init = ucode_plugin_init,
 439 };