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         printf("Status: 500 Internal Server Error\r\n\r\n"
 199        "Exception while executing ucode program %s:\n",
 200        current_prefix->handler);
 201
 202         switch (ex->type) {
 203         case EXCEPTION_SYNTAX:    printf("Syntax error");    break;
 204         case EXCEPTION_RUNTIME:   printf("Runtime error");   break;
 205         case EXCEPTION_TYPE:      printf("Type error");      break;
 206         case EXCEPTION_REFERENCE: printf("Reference error"); break;
 207         default:                  printf("Error");
 208         }
 209
 210         printf(": %s\n", ex->message);
 211
 212         ctx = ucv_object_get(ucv_array_get(ex->stacktrace, 0), "context", NULL);
 213
 214         if (ctx)
 215                 printf("%s\n", ucv_string_get(ctx));
 216 }
 217
 218 static void
 219 uh_ucode_state_init(struct ucode_prefix *ucode)
 220 {
 221         char *syntax_error = NULL;
 222         uc_vm_t *vm = &ucode->ctx;
 223         uc_function_t *handler;
 224         uc_vm_status_t status;
 225         uc_source_t *src;
 226         uc_value_t *v;
 227         int exitcode;
 228
 229         uc_vm_init(vm, &config);
 230         uc_stdlib_load(uc_vm_scope_get(vm));
 231
 232         /* build uhttpd api table */
 233         v = ucv_object_new(vm);
 234
 235         ucv_object_add(v, "send", ucv_cfunction_new("send", uh_ucode_send));
 236         ucv_object_add(v, "sendc", ucv_get(ucv_object_get(v, "send", NULL)));
 237         ucv_object_add(v, "recv", ucv_cfunction_new("recv", uh_ucode_recv));
 238         ucv_object_add(v, "urldecode", ucv_cfunction_new("urldecode", uh_ucode_urldecode));
 239         ucv_object_add(v, "urlencode", ucv_cfunction_new("urlencode", uh_ucode_urlencode));
 240         ucv_object_add(v, "docroot", ucv_string_new(conf.docroot));
 241
 242         ucv_object_add(uc_vm_scope_get(vm), "uhttpd", v);
 243
 244         src = uc_source_new_file(ucode->handler);
 245
 246         if (!src) {
 247                 fprintf(stderr, "Error: Unable to open ucode handler: %s\n",
 248                         strerror(errno));
 249
 250                 exit(1);
 251         }
 252
 253         handler = uc_compile(&config, src, &syntax_error);
 254
 255         uc_source_put(src);
 256
 257         if (!handler) {
 258                 fprintf(stderr, "Error: Unable to compile ucode handler: %s\n",
 259                         syntax_error);
 260
 261                 exit(1);
 262         }
 263
 264         free(syntax_error);
 265
 266         vm->output = fopen("/dev/null", "w");
 267
 268         if (!vm->output) {
 269                 fprintf(stderr, "Error: Unable to open /dev/null for writing: %s\n",
 270                         strerror(errno));
 271
 272                 exit(1);
 273         }
 274
 275         status = uc_vm_execute(vm, handler, &v);
 276         exitcode = (int)ucv_int64_get(v);
 277
 278         ucv_put(v);
 279
 280         switch (status) {
 281         case STATUS_OK:
 282                 break;
 283
 284         case STATUS_EXIT:
 285                 fprintf(stderr, "Error: The ucode handler invoked exit(%d)\n", exitcode);
 286                 exit(exitcode ? exitcode : 1);
 287
 288         case ERROR_COMPILE:
 289                 fprintf(stderr, "Error: Compilation error while executing ucode handler\n");
 290                 exit(1);
 291
 292         case ERROR_RUNTIME:
 293                 fprintf(stderr, "Error: Runtime error while executing ucode handler\n");
 294                 exit(2);
 295         }
 296
 297         v = ucv_object_get(uc_vm_scope_get(vm), UH_UCODE_CB, NULL);
 298
 299         if (!ucv_is_callable(v)) {
 300                 fprintf(stderr, "Error: The ucode handler declares no " UH_UCODE_CB "() callback.\n");
 301                 exit(1);
 302         }
 303
 304         uc_vm_exception_handler_set(vm, uh_ucode_exception);
 305
 306         ucv_gc(vm);
 307
 308         fclose(vm->output);
 309
 310         vm->output = stdout;
 311 }
 312
 313 static void
 314 ucode_main(struct client *cl, struct path_info *pi, char *url)
 315 {
 316         uc_vm_t *vm = &current_prefix->ctx;
 317         uc_value_t *req, *hdr, *res;
 318         int path_len, prefix_len;
 319         struct blob_attr *cur;
 320         struct env_var *var;
 321         char *str;
 322         int rem;
 323
 324         /* new env table for this request */
 325         req = ucv_object_new(vm);
 326
 327         prefix_len = strlen(pi->name);
 328         path_len = strlen(url);
 329         str = strchr(url, '?');
 330
 331         if (str) {
 332                 if (*(str + 1))
 333                         pi->query = str + 1;
 334
 335                 path_len = str - url;
 336         }
 337
 338         if (prefix_len > 0 && pi->name[prefix_len - 1] == '/')
 339                 prefix_len--;
 340
 341         if (path_len > prefix_len) {
 342                 ucv_object_add(req, "PATH_INFO",
 343                         ucv_string_new_length(url + prefix_len, path_len - prefix_len));
 344         }
 345
 346         for (var = ops->get_process_vars(cl, pi); var->name; var++) {
 347                 if (!var->value)
 348                         continue;
 349
 350                 ucv_object_add(req, var->name, ucv_string_new(var->value));
 351         }
 352
 353         ucv_object_add(req, "HTTP_VERSION",
 354                 ucv_double_new(0.9 + (cl->request.version / 10.0)));
 355
 356         hdr = ucv_object_new(vm);
 357
 358         blob_for_each_attr(cur, cl->hdr.head, rem)
 359                 ucv_object_add(hdr, blobmsg_name(cur), ucv_string_new(blobmsg_data(cur)));
 360
 361         ucv_object_add(req, "headers", hdr);
 362
 363         res = uc_vm_invoke(vm, UH_UCODE_CB, 1, req);
 364
 365         ucv_put(req);
 366         ucv_put(res);
 367
 368         exit(0);
 369 }
 370
 371 static void
 372 ucode_handle_request(struct client *cl, char *url, struct path_info *pi)
 373 {
 374         struct ucode_prefix *p;
 375         static struct path_info _pi;
 376
 377         list_for_each_entry(p, &conf.ucode_prefix, list) {
 378                 if (!ops->path_match(p->prefix, url))
 379                         continue;
 380
 381                 pi = &_pi;
 382                 pi->name = p->prefix;
 383                 pi->phys = p->handler;
 384
 385                 current_prefix = p;
 386
 387                 if (!ops->create_process(cl, pi, url, ucode_main)) {
 388                         ops->client_error(cl, 500, "Internal Server Error",
 389                                           "Failed to create CGI process: %s",
 390                                           strerror(errno));
 391                 }
 392
 393                 return;
 394         }
 395
 396         ops->client_error(cl, 500, "Internal Server Error",
 397                           "Failed to lookup matching handler");
 398 }
 399
 400 static bool
 401 check_ucode_url(const char *url)
 402 {
 403         struct ucode_prefix *p;
 404
 405         list_for_each_entry(p, &conf.ucode_prefix, list)
 406                 if (ops->path_match(p->prefix, url))
 407                         return true;
 408
 409         return false;
 410 }
 411
 412 static struct dispatch_handler ucode_dispatch = {
 413         .script = true,
 414         .check_url = check_ucode_url,
 415         .handle_request = ucode_handle_request,
 416 };
 417
 418 static int
 419 ucode_plugin_init(const struct uhttpd_ops *o, struct config *c)
 420 {
 421         struct ucode_prefix *p;
 422
 423         ops = o;
 424         _conf = c;
 425
 426         list_for_each_entry(p, &conf.ucode_prefix, list)
 427                 uh_ucode_state_init(p);
 428
 429         ops->dispatch_add(&ucode_dispatch);
 430         return 0;
 431 }
 432
 433 struct uhttpd_plugin uhttpd_plugin = {
 434         .init = ucode_plugin_init,
 435 };