proc.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 <arpa/inet.h>
  21 #include <libubox/blobmsg.h>
  22 #include "uhttpd.h"
  23
  24 #define __headers \
  25         __header(accept, accept) \
  26         __header(accept_charset, accept-charset) \
  27         __header(accept_encoding, accept-encoding) \
  28         __header(accept_language, accept-language) \
  29         __header(authorization, authorization) \
  30         __header(connection, connection) \
  31         __header(cookie, cookie) \
  32         __header(host, host) \
  33         __header(referer, referer) \
  34         __header(user_agent, user-agent) \
  35         __header(content_type, content-type) \
  36         __header(content_length, content-length) \
  37         __header(x_http_method_override, x-http-method-override) \
  38         __header(http_auth_user, http-auth-user) \
  39         __header(http_auth_pass, http-auth-pass)
  40
  41 #undef __header
  42 #define __header __enum_header
  43 enum client_hdr {
  44         __headers
  45         __HDR_MAX,
  46 };
  47
  48 #undef __header
  49 #define __header __blobmsg_header
  50 static const struct blobmsg_policy hdr_policy[__HDR_MAX] = {
  51         __headers
  52 };
  53
  54 static const struct {
  55         const char *name;
  56         int idx;
  57 } proc_header_env[] = {
  58         { "HTTP_ACCEPT", HDR_accept },
  59         { "HTTP_ACCEPT_CHARSET", HDR_accept_charset },
  60         { "HTTP_ACCEPT_ENCODING", HDR_accept_encoding },
  61         { "HTTP_ACCEPT_LANGUAGE", HDR_accept_language },
  62         { "HTTP_AUTHORIZATION", HDR_authorization },
  63         { "HTTP_CONNECTION", HDR_connection },
  64         { "HTTP_COOKIE", HDR_cookie },
  65         { "HTTP_HOST", HDR_host },
  66         { "HTTP_REFERER", HDR_referer },
  67         { "HTTP_USER_AGENT", HDR_user_agent },
  68         { "HTTP_X_HTTP_METHOD_OVERRIDE", HDR_x_http_method_override },
  69         { "HTTP_AUTH_USER", HDR_http_auth_user },
  70         { "HTTP_AUTH_PASS", HDR_http_auth_pass },
  71         { "CONTENT_TYPE", HDR_content_type },
  72         { "CONTENT_LENGTH", HDR_content_length },
  73 };
  74
  75 enum extra_vars {
  76         /* no update needed */
  77         _VAR_GW,
  78         _VAR_SOFTWARE,
  79
  80         /* updated by uh_get_process_vars */
  81         VAR_SCRIPT_NAME,
  82         VAR_SCRIPT_FILE,
  83         VAR_DOCROOT,
  84         VAR_QUERY,
  85         VAR_REQUEST,
  86         VAR_PROTO,
  87         VAR_METHOD,
  88         VAR_PATH_INFO,
  89         VAR_USER,
  90         VAR_HTTPS,
  91         VAR_REDIRECT,
  92         VAR_SERVER_NAME,
  93         VAR_SERVER_ADDR,
  94         VAR_SERVER_PORT,
  95         VAR_REMOTE_NAME,
  96         VAR_REMOTE_ADDR,
  97         VAR_REMOTE_PORT,
  98
  99         __VAR_MAX,
 100 };
 101
 102 static char local_addr[INET6_ADDRSTRLEN], remote_addr[INET6_ADDRSTRLEN];
 103 static char local_port[6], remote_port[6];
 104 static char redirect_status[4];
 105
 106 static struct env_var extra_vars[] = {
 107         [_VAR_GW] = { "GATEWAY_INTERFACE", "CGI/1.1" },
 108         [_VAR_SOFTWARE] = { "SERVER_SOFTWARE", "uhttpd" },
 109         [VAR_SCRIPT_NAME] = { "SCRIPT_NAME" },
 110         [VAR_SCRIPT_FILE] = { "SCRIPT_FILENAME" },
 111         [VAR_DOCROOT] = { "DOCUMENT_ROOT" },
 112         [VAR_QUERY] = { "QUERY_STRING" },
 113         [VAR_REQUEST] = { "REQUEST_URI" },
 114         [VAR_PROTO] = { "SERVER_PROTOCOL" },
 115         [VAR_METHOD] = { "REQUEST_METHOD" },
 116         [VAR_PATH_INFO] = { "PATH_INFO" },
 117         [VAR_USER] = { "REMOTE_USER" },
 118         [VAR_HTTPS] = { "HTTPS" },
 119         [VAR_REDIRECT] = { "REDIRECT_STATUS", redirect_status },
 120         [VAR_SERVER_NAME] = { "SERVER_NAME", local_addr },
 121         [VAR_SERVER_ADDR] = { "SERVER_ADDR", local_addr },
 122         [VAR_SERVER_PORT] = { "SERVER_PORT", local_port },
 123         [VAR_REMOTE_NAME] = { "REMOTE_HOST", remote_addr },
 124         [VAR_REMOTE_ADDR] = { "REMOTE_ADDR", remote_addr },
 125         [VAR_REMOTE_PORT] = { "REMOTE_PORT", remote_port },
 126 };
 127
 128 struct env_var *uh_get_process_vars(struct client *cl, struct path_info *pi)
 129 {
 130         struct http_request *req = &cl->request;
 131         struct blob_attr *data = cl->hdr.head;
 132         struct env_var *vars = (void *) uh_buf;
 133         struct blob_attr *tb[__HDR_MAX];
 134         const char *url;
 135         int len;
 136         int i;
 137
 138         url = blobmsg_data(blob_data(cl->hdr.head));
 139         len = ARRAY_SIZE(proc_header_env);
 140         len += ARRAY_SIZE(extra_vars);
 141         len *= sizeof(struct env_var);
 142
 143         BUILD_BUG_ON(sizeof(uh_buf) < len);
 144
 145         extra_vars[VAR_SCRIPT_NAME].value = pi->name;
 146         extra_vars[VAR_SCRIPT_FILE].value = pi->phys;
 147         extra_vars[VAR_DOCROOT].value = pi->root;
 148         extra_vars[VAR_QUERY].value = pi->query ? pi->query : "";
 149         extra_vars[VAR_REQUEST].value = url;
 150         extra_vars[VAR_PROTO].value = http_versions[req->version];
 151         extra_vars[VAR_METHOD].value = http_methods[req->method];
 152         extra_vars[VAR_PATH_INFO].value = pi->info;
 153         extra_vars[VAR_USER].value = req->realm ? req->realm->user : NULL;
 154         extra_vars[VAR_HTTPS].value = cl->tls ? "on" : NULL;
 155
 156         snprintf(redirect_status, sizeof(redirect_status),
 157                  "%d", req->redirect_status);
 158         inet_ntop(cl->srv_addr.family, &cl->srv_addr.in, local_addr, sizeof(local_addr));
 159         snprintf(local_port, sizeof(local_port), "%d", cl->srv_addr.port);
 160         inet_ntop(cl->peer_addr.family, &cl->peer_addr.in, remote_addr, sizeof(remote_addr));
 161         snprintf(remote_port, sizeof(remote_port), "%d", cl->peer_addr.port);
 162
 163         blobmsg_parse(hdr_policy, __HDR_MAX, tb, blob_data(data), blob_len(data));
 164         for (i = 0; i < ARRAY_SIZE(proc_header_env); i++) {
 165                 struct blob_attr *cur;
 166
 167                 cur = tb[proc_header_env[i].idx];
 168                 vars[i].name = proc_header_env[i].name;
 169                 vars[i].value = cur ? blobmsg_data(cur) : NULL;
 170         }
 171
 172         memcpy(&vars[i], extra_vars, sizeof(extra_vars));
 173         i += ARRAY_SIZE(extra_vars);
 174         vars[i].name = NULL;
 175         vars[i].value = NULL;
 176
 177         return vars;
 178 }
 179
 180 static void proc_close_fds(struct client *cl)
 181 {
 182         struct dispatch_proc *p = &cl->dispatch.proc;
 183
 184         close(p->r.sfd.fd.fd);
 185         if (p->wrfd.fd >= 0)
 186                 close(p->wrfd.fd);
 187 }
 188
 189 static void proc_handle_close(struct relay *r, int ret)
 190 {
 191         if (r->header_cb) {
 192                 uh_client_error(r->cl, 502, "Bad Gateway",
 193                                 "The process did not produce any response");
 194                 return;
 195         }
 196
 197         uh_request_done(r->cl);
 198 }
 199
 200 static void proc_handle_header(struct relay *r, const char *name, const char *val)
 201 {
 202         static char status_buf[64];
 203         struct client *cl = r->cl;
 204         char *sep;
 205         char buf[4];
 206
 207         if (!strcmp(name, "Status")) {
 208                 sep = strchr(val, ' ');
 209                 if (sep != val + 3)
 210                         return;
 211
 212                 memcpy(buf, val, 3);
 213                 buf[3] = 0;
 214                 snprintf(status_buf, sizeof(status_buf), "%s", sep + 1);
 215                 cl->dispatch.proc.status_msg = status_buf;
 216                 cl->dispatch.proc.status_code = atoi(buf);
 217                 return;
 218         }
 219
 220         blobmsg_add_string(&cl->dispatch.proc.hdr, name, val);
 221 }
 222
 223 static void proc_handle_header_end(struct relay *r)
 224 {
 225         struct client *cl = r->cl;
 226         struct dispatch_proc *p = &cl->dispatch.proc;
 227         struct blob_attr *cur;
 228         int rem;
 229
 230         uloop_timeout_cancel(&p->timeout);
 231         uh_http_header(cl, cl->dispatch.proc.status_code, cl->dispatch.proc.status_msg);
 232         blob_for_each_attr(cur, cl->dispatch.proc.hdr.head, rem)
 233                 ustream_printf(cl->us, "%s: %s\r\n", blobmsg_name(cur), blobmsg_data(cur));
 234
 235         ustream_printf(cl->us, "\r\n");
 236
 237         if (cl->request.method == UH_HTTP_MSG_HEAD)
 238                 r->skip_data = true;
 239 }
 240
 241 static void proc_write_close(struct client *cl)
 242 {
 243         struct dispatch_proc *p = &cl->dispatch.proc;
 244
 245         if (p->wrfd.fd < 0)
 246                 return;
 247
 248         uloop_fd_delete(&p->wrfd);
 249         close(p->wrfd.fd);
 250         p->wrfd.fd = -1;
 251 }
 252
 253 static void proc_free(struct client *cl)
 254 {
 255         struct dispatch_proc *p = &cl->dispatch.proc;
 256
 257         uloop_timeout_cancel(&p->timeout);
 258         blob_buf_free(&p->hdr);
 259         proc_write_close(cl);
 260         uh_relay_free(&p->r);
 261 }
 262
 263 static void proc_write_cb(struct uloop_fd *fd, unsigned int events)
 264 {
 265         struct client *cl = container_of(fd, struct client, dispatch.proc.wrfd);
 266
 267         client_poll_post_data(cl);
 268         cl->dispatch.data_blocked = false;
 269 }
 270
 271 static void proc_relay_write_cb(struct client *cl)
 272 {
 273         struct dispatch_proc *p = &cl->dispatch.proc;
 274
 275         if (ustream_pending_data(cl->us, true))
 276                 return;
 277
 278         ustream_set_read_blocked(&p->r.sfd.stream, false);
 279         p->r.sfd.stream.notify_read(&p->r.sfd.stream, 0);
 280 }
 281
 282 static int proc_data_send(struct client *cl, const char *data, int len)
 283 {
 284         struct dispatch_proc *p = &cl->dispatch.proc;
 285         int retlen = 0;
 286         int ret;
 287
 288         while (len) {
 289                 ret = write(p->wrfd.fd, data, len);
 290
 291                 if (ret < 0) {
 292                         if (errno == EINTR)
 293                                 continue;
 294
 295                         if (errno == EAGAIN || errno == EWOULDBLOCK) {
 296                                 cl->dispatch.data_blocked = true;
 297                                 break;
 298                         }
 299
 300                         /* consume all data */
 301                         ret = len;
 302                 }
 303
 304                 if (!ret)
 305                         break;
 306
 307                 retlen += ret;
 308                 len -= ret;
 309                 data += ret;
 310         }
 311
 312         if (len)
 313                 uloop_fd_add(&p->wrfd, ULOOP_WRITE);
 314         else
 315                 uloop_fd_delete(&p->wrfd);
 316
 317         return retlen;
 318 }
 319
 320 static void proc_timeout_cb(struct uloop_timeout *timeout)
 321 {
 322         struct dispatch_proc *proc = container_of(timeout, struct dispatch_proc, timeout);
 323         struct client *cl = container_of(proc, struct client, dispatch.proc);
 324
 325         uh_relay_kill(cl, &proc->r);
 326 }
 327
 328 bool uh_create_process(struct client *cl, struct path_info *pi, char *url,
 329                        void (*cb)(struct client *cl, struct path_info *pi, char *url))
 330 {
 331         struct dispatch *d = &cl->dispatch;
 332         struct dispatch_proc *proc = &d->proc;
 333         int rfd[2], wfd[2];
 334         int pid;
 335
 336         blob_buf_init(&proc->hdr, 0);
 337         proc->status_code = 200;
 338         proc->status_msg = "OK";
 339
 340         if (pipe(rfd))
 341                 return false;
 342
 343         if (pipe(wfd))
 344                 goto close_rfd;
 345
 346         pid = fork();
 347         if (pid < 0)
 348                 goto close_wfd;
 349
 350         if (!pid) {
 351                 close(0);
 352                 close(1);
 353
 354                 dup2(rfd[1], 1);
 355                 dup2(wfd[0], 0);
 356
 357                 close(rfd[0]);
 358                 close(rfd[1]);
 359                 close(wfd[0]);
 360                 close(wfd[1]);
 361
 362                 uh_close_fds();
 363                 cb(cl, pi, url);
 364                 exit(0);
 365         }
 366
 367         close(rfd[1]);
 368         close(wfd[0]);
 369
 370         proc->wrfd.fd = wfd[1];
 371         uh_relay_open(cl, &proc->r, rfd[0], pid);
 372         uloop_fd_add(&proc->wrfd, ULOOP_WRITE);
 373
 374         d->free = proc_free;
 375         d->close_fds = proc_close_fds;
 376         d->data_send = proc_data_send;
 377         d->data_done = proc_write_close;
 378         d->write_cb = proc_relay_write_cb;
 379         proc->r.header_cb = proc_handle_header;
 380         proc->r.header_end = proc_handle_header_end;
 381         proc->r.close = proc_handle_close;
 382         proc->wrfd.cb = proc_write_cb;
 383         proc->timeout.cb = proc_timeout_cb;
 384         if (conf.script_timeout > 0)
 385                 uloop_timeout_set(&proc->timeout, conf.script_timeout * 1000);
 386
 387         return true;
 388
 389 close_wfd:
 390         close(wfd[0]);
 391         close(wfd[1]);
 392 close_rfd:
 393         close(rfd[0]);
 394         close(rfd[1]);
 395
 396         return false;
 397 }