proc.c

   1 /*
   2  * uhttpd - Tiny single-threaded httpd
   3  *
   4  *   Copyright (C) 2010-2012 Jo-Philipp Wich <xm@subsignal.org>
   5  *   Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
   6  *
   7  *  Licensed under the Apache License, Version 2.0 (the "License");
   8  *  you may not use this file except in compliance with the License.
   9  *  You may obtain a copy of the License at
  10  *
  11  *      http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  *  Unless required by applicable law or agreed to in writing, software
  14  *  distributed under the License is distributed on an "AS IS" BASIS,
  15  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  *  See the License for the specific language governing permissions and
  17  *  limitations under the License.
  18  */
  19
  20 #include <arpa/inet.h>
  21 #include <libubox/blobmsg.h>
  22 #include "uhttpd.h"
  23
  24 #define __headers \
  25         __header(accept) \
  26         __header(accept_charset) \
  27         __header(accept_encoding) \
  28         __header(accept_language) \
  29         __header(authorization) \
  30         __header(connection) \
  31         __header(cookie) \
  32         __header(host) \
  33         __header(referer) \
  34         __header(user_agent) \
  35         __header(content_type) \
  36         __header(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         inet_ntop(cl->peer_addr.family, &cl->peer_addr.in, remote_addr, sizeof(remote_addr));
 151
 152         blobmsg_parse(hdr_policy, __HDR_MAX, tb, blob_data(data), blob_len(data));
 153         for (i = 0; i < ARRAY_SIZE(proc_header_env); i++) {
 154                 struct blob_attr *cur;
 155
 156                 cur = tb[proc_header_env[i].idx];
 157                 vars[i].name = proc_header_env[i].name;
 158                 vars[i].value = cur ? blobmsg_data(cur) : "";
 159         }
 160
 161         memcpy(&vars[i], extra_vars, sizeof(extra_vars));
 162         i += ARRAY_SIZE(extra_vars);
 163         vars[i].name = NULL;
 164         vars[i].value = NULL;
 165
 166         return vars;
 167 }
 168
 169 static void proc_close_fds(struct client *cl)
 170 {
 171         close(cl->dispatch.proc.r.sfd.fd.fd);
 172 }
 173
 174 static void proc_handle_close(struct relay *r, int ret)
 175 {
 176         if (r->header_cb) {
 177                 uh_client_error(r->cl, 502, "Bad Gateway",
 178                                 "The process did not produce any response");
 179                 return;
 180         }
 181
 182         uh_request_done(r->cl);
 183 }
 184
 185 static void proc_handle_header(struct relay *r, const char *name, const char *val)
 186 {
 187         static char status_buf[64];
 188         struct client *cl = r->cl;
 189         char *sep;
 190         char buf[4];
 191
 192         if (!strcmp(name, "Status")) {
 193                 sep = strchr(val, ' ');
 194                 if (sep != val + 3)
 195                         return;
 196
 197                 memcpy(buf, val, 3);
 198                 buf[3] = 0;
 199                 snprintf(status_buf, sizeof(status_buf), "%s", sep + 1);
 200                 cl->dispatch.proc.status_msg = status_buf;
 201                 cl->dispatch.proc.status_code = atoi(buf);
 202                 return;
 203         }
 204
 205         blobmsg_add_string(&cl->dispatch.proc.hdr, name, val);
 206 }
 207
 208 static void proc_handle_header_end(struct relay *r)
 209 {
 210         struct client *cl = r->cl;
 211         struct blob_attr *cur;
 212         int rem;
 213
 214         uh_http_header(cl, cl->dispatch.proc.status_code, cl->dispatch.proc.status_msg);
 215         blob_for_each_attr(cur, cl->dispatch.proc.hdr.head, rem)
 216                 ustream_printf(cl->us, "%s: %s\r\n", blobmsg_name(cur), blobmsg_data(cur));
 217
 218         ustream_printf(cl->us, "\r\n");
 219 }
 220
 221 static void proc_write_close(struct client *cl)
 222 {
 223         struct dispatch_proc *p = &cl->dispatch.proc;
 224
 225         if (p->wrfd.fd < 0)
 226                 return;
 227
 228         uloop_fd_delete(&p->wrfd);
 229         close(p->wrfd.fd);
 230         p->wrfd.fd = -1;
 231 }
 232
 233 static void proc_free(struct client *cl)
 234 {
 235         blob_buf_free(&cl->hdr);
 236         proc_write_close(cl);
 237         uh_relay_free(&cl->dispatch.proc.r);
 238 }
 239
 240 static void proc_write_cb(struct uloop_fd *fd, unsigned int events)
 241 {
 242         struct client *cl = container_of(fd, struct client, dispatch.proc.wrfd);
 243
 244         client_poll_post_data(cl);
 245 }
 246
 247 static int proc_data_send(struct client *cl, const char *data, int len)
 248 {
 249         struct dispatch_proc *p = &cl->dispatch.proc;
 250         int retlen = 0;
 251         int ret;
 252
 253         while (len) {
 254                 ret = write(p->wrfd.fd, data, len);
 255
 256                 if (ret < 0) {
 257                         if (errno == EINTR)
 258                                 continue;
 259
 260                         if (errno == EAGAIN || errno == EWOULDBLOCK)
 261                                 break;
 262
 263                         /* error, no retry */
 264                         len = 0;
 265                         break;
 266                 }
 267
 268                 if (!ret)
 269                         break;
 270
 271                 retlen += ret;
 272                 len -= ret;
 273                 data += ret;
 274         }
 275
 276         if (len)
 277                 uloop_fd_add(&p->wrfd, ULOOP_WRITE);
 278         else
 279                 uloop_fd_delete(&p->wrfd);
 280
 281         return retlen;
 282 }
 283
 284 bool uh_create_process(struct client *cl, struct path_info *pi,
 285                        void (*cb)(struct client *cl, struct path_info *pi))
 286 {
 287         struct dispatch *d = &cl->dispatch;
 288         struct dispatch_proc *proc = &d->proc;
 289         int rfd[2], wfd[2];
 290         int pid;
 291
 292         blob_buf_init(&proc->hdr, 0);
 293         proc->status_code = 200;
 294         proc->status_msg = "OK";
 295
 296         if (pipe(rfd))
 297                 return false;
 298
 299         if (pipe(wfd))
 300                 goto close_rfd;
 301
 302         pid = fork();
 303         if (pid < 0)
 304                 goto close_wfd;
 305
 306         if (!pid) {
 307                 close(0);
 308                 close(1);
 309
 310                 dup2(rfd[1], 1);
 311                 dup2(wfd[0], 0);
 312
 313                 close(rfd[0]);
 314                 close(rfd[1]);
 315                 close(wfd[0]);
 316                 close(wfd[1]);
 317
 318                 uh_close_fds();
 319                 cb(cl, pi);
 320                 exit(0);
 321         }
 322
 323         close(rfd[1]);
 324         close(wfd[0]);
 325
 326         proc->wrfd.fd = wfd[1];
 327         uh_relay_open(cl, &proc->r, rfd[0], pid);
 328
 329         d->free = proc_free;
 330         d->close_fds = proc_close_fds;
 331         d->data_send = proc_data_send;
 332         d->data_done = proc_write_close;
 333         proc->r.header_cb = proc_handle_header;
 334         proc->r.header_end = proc_handle_header_end;
 335         proc->r.close = proc_handle_close;
 336         proc->wrfd.cb = proc_write_cb;
 337
 338         return true;
 339
 340 close_wfd:
 341         close(wfd[0]);
 342         close(wfd[1]);
 343 close_rfd:
 344         close(rfd[0]);
 345         close(rfd[1]);
 346
 347         return false;
 348 }