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