external/bsd/libevent/dist/sample/http-server.c

   1 /*      $NetBSD: http-server.c,v 1.1.1.2 2015/01/29 06:38:19 spz Exp $  */
   2 /*
   3   A trivial static http webserver using Libevent's evhttp.
   4
   5   This is not the best code in the world, and it does some fairly stupid stuff
   6   that you would never want to do in a production webserver. Caveat hackor!
   7
   8  */
   9
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <string.h>
  13
  14 #include <sys/types.h>
  15 #include <sys/stat.h>
  16
  17 #ifdef WIN32
  18 #include <winsock2.h>
  19 #include <ws2tcpip.h>
  20 #include <windows.h>
  21 #include <io.h>
  22 #include <fcntl.h>
  23 #ifndef S_ISDIR
  24 #define S_ISDIR(x) (((x) & S_IFMT) == S_IFDIR)
  25 #endif
  26 #else
  27 #include <sys/stat.h>
  28 #include <sys/socket.h>
  29 #include <signal.h>
  30 #include <fcntl.h>
  31 #include <unistd.h>
  32 #include <dirent.h>
  33 #endif
  34
  35 #include <event2/event.h>
  36 #include <event2/http.h>
  37 #include <event2/buffer.h>
  38 #include <event2/util.h>
  39 #include <event2/keyvalq_struct.h>
  40
  41 #ifdef _EVENT_HAVE_NETINET_IN_H
  42 #include <netinet/in.h>
  43 # ifdef _XOPEN_SOURCE_EXTENDED
  44 #  include <arpa/inet.h>
  45 # endif
  46 #endif
  47
  48 /* Compatibility for possible missing IPv6 declarations */
  49 #include "../util-internal.h"
  50
  51 #ifdef WIN32
  52 #define stat _stat
  53 #define fstat _fstat
  54 #define open _open
  55 #define close _close
  56 #define O_RDONLY _O_RDONLY
  57 #endif
  58
  59 char uri_root[512];
  60
  61 static const struct table_entry {
  62         const char *extension;
  63         const char *content_type;
  64 } content_type_table[] = {
  65         { "txt", "text/plain" },
  66         { "c", "text/plain" },
  67         { "h", "text/plain" },
  68         { "html", "text/html" },
  69         { "htm", "text/htm" },
  70         { "css", "text/css" },
  71         { "gif", "image/gif" },
  72         { "jpg", "image/jpeg" },
  73         { "jpeg", "image/jpeg" },
  74         { "png", "image/png" },
  75         { "pdf", "application/pdf" },
  76         { "ps", "application/postsript" },
  77         { NULL, NULL },
  78 };
  79
  80 /* Try to guess a good content-type for 'path' */
  81 static const char *
  82 guess_content_type(const char *path)
  83 {
  84         const char *last_period, *extension;
  85         const struct table_entry *ent;
  86         last_period = strrchr(path, '.');
  87         if (!last_period || strchr(last_period, '/'))
  88                 goto not_found; /* no exension */
  89         extension = last_period + 1;
  90         for (ent = &content_type_table[0]; ent->extension; ++ent) {
  91                 if (!evutil_ascii_strcasecmp(ent->extension, extension))
  92                         return ent->content_type;
  93         }
  94
  95 not_found:
  96         return "application/misc";
  97 }
  98
  99 /* Callback used for the /dump URI, and for every non-GET request:
 100  * dumps all information to stdout and gives back a trivial 200 ok */
 101 static void
 102 dump_request_cb(struct evhttp_request *req, void *arg)
 103 {
 104         const char *cmdtype;
 105         struct evkeyvalq *headers;
 106         struct evkeyval *header;
 107         struct evbuffer *buf;
 108
 109         switch (evhttp_request_get_command(req)) {
 110         case EVHTTP_REQ_GET: cmdtype = "GET"; break;
 111         case EVHTTP_REQ_POST: cmdtype = "POST"; break;
 112         case EVHTTP_REQ_HEAD: cmdtype = "HEAD"; break;
 113         case EVHTTP_REQ_PUT: cmdtype = "PUT"; break;
 114         case EVHTTP_REQ_DELETE: cmdtype = "DELETE"; break;
 115         case EVHTTP_REQ_OPTIONS: cmdtype = "OPTIONS"; break;
 116         case EVHTTP_REQ_TRACE: cmdtype = "TRACE"; break;
 117         case EVHTTP_REQ_CONNECT: cmdtype = "CONNECT"; break;
 118         case EVHTTP_REQ_PATCH: cmdtype = "PATCH"; break;
 119         default: cmdtype = "unknown"; break;
 120         }
 121
 122         printf("Received a %s request for %s\nHeaders:\n",
 123             cmdtype, evhttp_request_get_uri(req));
 124
 125         headers = evhttp_request_get_input_headers(req);
 126         for (header = headers->tqh_first; header;
 127             header = header->next.tqe_next) {
 128                 printf("  %s: %s\n", header->key, header->value);
 129         }
 130
 131         buf = evhttp_request_get_input_buffer(req);
 132         puts("Input data: <<<");
 133         while (evbuffer_get_length(buf)) {
 134                 int n;
 135                 char cbuf[128];
 136                 n = evbuffer_remove(buf, cbuf, sizeof(cbuf));
 137                 if (n > 0)
 138                         (void) fwrite(cbuf, 1, n, stdout);
 139         }
 140         puts(">>>");
 141
 142         evhttp_send_reply(req, 200, "OK", NULL);
 143 }
 144
 145 /* This callback gets invoked when we get any http request that doesn't match
 146  * any other callback.  Like any evhttp server callback, it has a simple job:
 147  * it must eventually call evhttp_send_error() or evhttp_send_reply().
 148  */
 149 static void
 150 send_document_cb(struct evhttp_request *req, void *arg)
 151 {
 152         struct evbuffer *evb = NULL;
 153         const char *docroot = arg;
 154         const char *uri = evhttp_request_get_uri(req);
 155         struct evhttp_uri *decoded = NULL;
 156         const char *path;
 157         char *decoded_path;
 158         char *whole_path = NULL;
 159         size_t len;
 160         int fd = -1;
 161         struct stat st;
 162
 163         if (evhttp_request_get_command(req) != EVHTTP_REQ_GET) {
 164                 dump_request_cb(req, arg);
 165                 return;
 166         }
 167
 168         printf("Got a GET request for <%s>\n",  uri);
 169
 170         /* Decode the URI */
 171         decoded = evhttp_uri_parse(uri);
 172         if (!decoded) {
 173                 printf("It's not a good URI. Sending BADREQUEST\n");
 174                 evhttp_send_error(req, HTTP_BADREQUEST, 0);
 175                 return;
 176         }
 177
 178         /* Let's see what path the user asked for. */
 179         path = evhttp_uri_get_path(decoded);
 180         if (!path) path = "/";
 181
 182         /* We need to decode it, to see what path the user really wanted. */
 183         decoded_path = evhttp_uridecode(path, 0, NULL);
 184         if (decoded_path == NULL)
 185                 goto err;
 186         /* Don't allow any ".."s in the path, to avoid exposing stuff outside
 187          * of the docroot.  This test is both overzealous and underzealous:
 188          * it forbids aceptable paths like "/this/one..here", but it doesn't
 189          * do anything to prevent symlink following." */
 190         if (strstr(decoded_path, ".."))
 191                 goto err;
 192
 193         len = strlen(decoded_path)+strlen(docroot)+2;
 194         if (!(whole_path = malloc(len))) {
 195                 perror("malloc");
 196                 goto err;
 197         }
 198         evutil_snprintf(whole_path, len, "%s/%s", docroot, decoded_path);
 199
 200         if (stat(whole_path, &st)<0) {
 201                 goto err;
 202         }
 203
 204         /* This holds the content we're sending. */
 205         evb = evbuffer_new();
 206
 207         if (S_ISDIR(st.st_mode)) {
 208                 /* If it's a directory, read the comments and make a little
 209                  * index page */
 210 #ifdef WIN32
 211                 HANDLE d;
 212                 WIN32_FIND_DATAA ent;
 213                 char *pattern;
 214                 size_t dirlen;
 215 #else
 216                 DIR *d;
 217                 struct dirent *ent;
 218 #endif
 219                 const char *trailing_slash = "";
 220
 221                 if (!strlen(path) || path[strlen(path)-1] != '/')
 222                         trailing_slash = "/";
 223
 224 #ifdef WIN32
 225                 dirlen = strlen(whole_path);
 226                 pattern = malloc(dirlen+3);
 227                 memcpy(pattern, whole_path, dirlen);
 228                 pattern[dirlen] = '\\';
 229                 pattern[dirlen+1] = '*';
 230                 pattern[dirlen+2] = '\0';
 231                 d = FindFirstFileA(pattern, &ent);
 232                 free(pattern);
 233                 if (d == INVALID_HANDLE_VALUE)
 234                         goto err;
 235 #else
 236                 if (!(d = opendir(whole_path)))
 237                         goto err;
 238 #endif
 239
 240                 evbuffer_add_printf(evb, "<html>\n <head>\n"
 241                     "  <title>%s</title>\n"
 242                     "  <base href='%s%s%s'>\n"
 243                     " </head>\n"
 244                     " <body>\n"
 245                     "  <h1>%s</h1>\n"
 246                     "  <ul>\n",
 247                     decoded_path, /* XXX html-escape this. */
 248                     uri_root, path, /* XXX html-escape this? */
 249                     trailing_slash,
 250                     decoded_path /* XXX html-escape this */);
 251 #ifdef WIN32
 252                 do {
 253                         const char *name = ent.cFileName;
 254 #else
 255                 while ((ent = readdir(d))) {
 256                         const char *name = ent->d_name;
 257 #endif
 258                         evbuffer_add_printf(evb,
 259                             "    <li><a href=\"%s\">%s</a>\n",
 260                             name, name);/* XXX escape this */
 261 #ifdef WIN32
 262                 } while (FindNextFileA(d, &ent));
 263 #else
 264                 }
 265 #endif
 266                 evbuffer_add_printf(evb, "</ul></body></html>\n");
 267 #ifdef WIN32
 268                 FindClose(d);
 269 #else
 270                 closedir(d);
 271 #endif
 272                 evhttp_add_header(evhttp_request_get_output_headers(req),
 273                     "Content-Type", "text/html");
 274         } else {
 275                 /* Otherwise it's a file; add it to the buffer to get
 276                  * sent via sendfile */
 277                 const char *type = guess_content_type(decoded_path);
 278                 if ((fd = open(whole_path, O_RDONLY)) < 0) {
 279                         perror("open");
 280                         goto err;
 281                 }
 282
 283                 if (fstat(fd, &st)<0) {
 284                         /* Make sure the length still matches, now that we
 285                          * opened the file :/ */
 286                         perror("fstat");
 287                         goto err;
 288                 }
 289                 evhttp_add_header(evhttp_request_get_output_headers(req),
 290                     "Content-Type", type);
 291                 evbuffer_add_file(evb, fd, 0, st.st_size);
 292         }
 293
 294         evhttp_send_reply(req, 200, "OK", evb);
 295         goto done;
 296 err:
 297         evhttp_send_error(req, 404, "Document was not found");
 298         if (fd>=0)
 299                 close(fd);
 300 done:
 301         if (decoded)
 302                 evhttp_uri_free(decoded);
 303         if (decoded_path)
 304                 free(decoded_path);
 305         if (whole_path)
 306                 free(whole_path);
 307         if (evb)
 308                 evbuffer_free(evb);
 309 }
 310
 311 static void
 312 syntax(void)
 313 {
 314         fprintf(stdout, "Syntax: http-server <docroot>\n");
 315 }
 316
 317 int
 318 main(int argc, char **argv)
 319 {
 320         struct event_base *base;
 321         struct evhttp *http;
 322         struct evhttp_bound_socket *handle;
 323
 324         unsigned short port = 0;
 325 #ifdef WIN32
 326         WSADATA WSAData;
 327         WSAStartup(0x101, &WSAData);
 328 #else
 329         if (signal(SIGPIPE, SIG_IGN) == SIG_ERR)
 330                 return (1);
 331 #endif
 332         if (argc < 2) {
 333                 syntax();
 334                 return 1;
 335         }
 336
 337         base = event_base_new();
 338         if (!base) {
 339                 fprintf(stderr, "Couldn't create an event_base: exiting\n");
 340                 return 1;
 341         }
 342
 343         /* Create a new evhttp object to handle requests. */
 344         http = evhttp_new(base);
 345         if (!http) {
 346                 fprintf(stderr, "couldn't create evhttp. Exiting.\n");
 347                 return 1;
 348         }
 349
 350         /* The /dump URI will dump all requests to stdout and say 200 ok. */
 351         evhttp_set_cb(http, "/dump", dump_request_cb, NULL);
 352
 353         /* We want to accept arbitrary requests, so we need to set a "generic"
 354          * cb.  We can also add callbacks for specific paths. */
 355         evhttp_set_gencb(http, send_document_cb, argv[1]);
 356
 357         /* Now we tell the evhttp what port to listen on */
 358         handle = evhttp_bind_socket_with_handle(http, "0.0.0.0", port);
 359         if (!handle) {
 360                 fprintf(stderr, "couldn't bind to port %d. Exiting.\n",
 361                     (int)port);
 362                 return 1;
 363         }
 364
 365         {
 366                 /* Extract and display the address we're listening on. */
 367                 struct sockaddr_storage ss;
 368                 evutil_socket_t fd;
 369                 ev_socklen_t socklen = sizeof(ss);
 370                 char addrbuf[128];
 371                 void *inaddr;
 372                 const char *addr;
 373                 int got_port = -1;
 374                 fd = evhttp_bound_socket_get_fd(handle);
 375                 memset(&ss, 0, sizeof(ss));
 376                 if (getsockname(fd, (struct sockaddr *)&ss, &socklen)) {
 377                         perror("getsockname() failed");
 378                         return 1;
 379                 }
 380                 if (ss.ss_family == AF_INET) {
 381                         got_port = ntohs(((struct sockaddr_in*)&ss)->sin_port);
 382                         inaddr = &((struct sockaddr_in*)&ss)->sin_addr;
 383                 } else if (ss.ss_family == AF_INET6) {
 384                         got_port = ntohs(((struct sockaddr_in6*)&ss)->sin6_port);
 385                         inaddr = &((struct sockaddr_in6*)&ss)->sin6_addr;
 386                 } else {
 387                         fprintf(stderr, "Weird address family %d\n",
 388                             ss.ss_family);
 389                         return 1;
 390                 }
 391                 addr = evutil_inet_ntop(ss.ss_family, inaddr, addrbuf,
 392                     sizeof(addrbuf));
 393                 if (addr) {
 394                         printf("Listening on %s:%d\n", addr, got_port);
 395                         evutil_snprintf(uri_root, sizeof(uri_root),
 396                             "http://%s:%d",addr,got_port);
 397                 } else {
 398                         fprintf(stderr, "evutil_inet_ntop failed\n");
 399                         return 1;
 400                 }
 401         }
 402
 403         event_base_dispatch(base);
 404
 405         return 0;
 406 }