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