uclient-example.c

   1 /*
   2  * uclient - ustream based protocol client library
   3  *
   4  * Copyright (C) 2014 Felix Fietkau <nbd@openwrt.org>
   5  *
   6  * Permission to use, copy, modify, and/or distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include <unistd.h>
  20 #include <stdio.h>
  21 #include <dlfcn.h>
  22 #include <getopt.h>
  23 #include <fcntl.h>
  24
  25 #include <libubox/blobmsg.h>
  26
  27 #include "uclient.h"
  28
  29 #ifdef __APPLE__
  30 #define LIB_EXT "dylib"
  31 #else
  32 #define LIB_EXT "so"
  33 #endif
  34
  35 static struct ustream_ssl_ctx *ssl_ctx;
  36 static const struct ustream_ssl_ops *ssl_ops;
  37 static int quiet = false;
  38 static const char *output_file;
  39 static int output_fd = -1;
  40 static int error_ret;
  41
  42 static int open_output_file(const char *path, bool create)
  43 {
  44         const char *str;
  45         char *filename;
  46         int len;
  47         int flags = O_WRONLY;
  48
  49         if (create)
  50                 flags |= O_CREAT;
  51
  52         if (output_file) {
  53                 if (!strcmp(output_file, "-"))
  54                         return STDOUT_FILENO;
  55
  56                 return open(output_file, flags, 0644);
  57         }
  58
  59         /* Don't automatically overwrite files if the name is derived from the URL */
  60         if (create)
  61                 flags |= O_EXCL;
  62
  63         len = strcspn(path, ";&");
  64         while (len > 0 && path[len - 1] == '/')
  65                 len--;
  66
  67         for (str = path + len - 1; str >= path; str--) {
  68                 if (*str == '/')
  69                         break;
  70         }
  71
  72         str++;
  73         len -= str - path;
  74
  75         if (len > 0) {
  76                 filename = alloca(len + 1);
  77                 strncpy(filename, str, len);
  78                 filename[len] = 0;
  79         } else {
  80                 filename = "index.html";
  81         }
  82
  83         return open(filename, flags, 0644);
  84 }
  85
  86 static void request_done(struct uclient *cl)
  87 {
  88         uclient_disconnect(cl);
  89         uloop_end();
  90 }
  91
  92 static void example_header_done(struct uclient *cl)
  93 {
  94         static int retries;
  95
  96         struct blob_attr *cur;
  97         int rem;
  98
  99         if (retries < 10 && uclient_http_redirect(cl)) {
 100                 if (!quiet)
 101                         fprintf(stderr, "Redirected to %s on %s\n", cl->url->location, cl->url->host);
 102
 103                 retries++;
 104                 return;
 105         }
 106
 107         retries = 0;
 108         if (!quiet) {
 109                 fprintf(stderr, "Headers (%d): \n", cl->status_code);
 110                 blobmsg_for_each_attr(cur, cl->meta, rem) {
 111                         fprintf(stderr, "%s=%s\n", blobmsg_name(cur), (char *) blobmsg_data(cur));
 112                 }
 113         }
 114
 115         switch (cl->status_code) {
 116         case 204:
 117         case 200:
 118                 output_fd = open_output_file(cl->url->location, true);
 119                 if (output_fd < 0) {
 120                         if (!quiet)
 121                                 perror("Cannot open output file");
 122                         error_ret = 3;
 123                         request_done(cl);
 124                 }
 125                 break;
 126
 127         default:
 128                 request_done(cl);
 129                 break;
 130         }
 131 }
 132
 133 static void example_read_data(struct uclient *cl)
 134 {
 135         char buf[256];
 136         int len;
 137
 138         if (output_fd < 0)
 139                 return;
 140
 141         while (1) {
 142                 len = uclient_read(cl, buf, sizeof(buf));
 143                 if (!len)
 144                         return;
 145
 146                 write(output_fd, buf, len);
 147         }
 148 }
 149
 150 static void msg_connecting(struct uclient *cl)
 151 {
 152         char addr[INET6_ADDRSTRLEN];
 153         int port;
 154
 155         if (quiet)
 156                 return;
 157
 158         uclient_get_addr(addr, &port, &cl->remote_addr);
 159         fprintf(stderr, "Connecting to %s %s:%d\n", cl->url->host, addr, port);
 160 }
 161
 162 static void init_request(struct uclient *cl)
 163 {
 164         uclient_connect(cl);
 165         msg_connecting(cl);
 166         uclient_http_set_request_type(cl, "GET");
 167         uclient_request(cl);
 168 }
 169
 170 static void example_eof(struct uclient *cl)
 171 {
 172         request_done(cl);
 173 }
 174
 175 static void example_error(struct uclient *cl, int code)
 176 {
 177         if (!quiet)
 178                 fprintf(stderr, "Error %d!\n", code);
 179
 180         request_done(cl);
 181 }
 182
 183 static const struct uclient_cb cb = {
 184         .header_done = example_header_done,
 185         .data_read = example_read_data,
 186         .data_eof = example_eof,
 187         .error = example_error,
 188 };
 189
 190 static int usage(const char *progname)
 191 {
 192         fprintf(stderr,
 193                 "Usage: %s [options] <URL>\n"
 194                 "Options:\n"
 195                 "       -O <file>:                      Redirect output to file (use \"-\" for stdout)\n"
 196                 "\n"
 197                 "HTTPS options:\n"
 198                 "       --ca-certificate=<cert>:        Load CA certificates from file <cert>\n"
 199                 "       --no-check-certificate:         don't validate the server's certificate\n"
 200                 "\n", progname);
 201         return 1;
 202 }
 203
 204
 205 static void init_ustream_ssl(void)
 206 {
 207         void *dlh;
 208
 209         dlh = dlopen("libustream-ssl." LIB_EXT, RTLD_LAZY | RTLD_LOCAL);
 210         if (!dlh)
 211                 return;
 212
 213         ssl_ops = dlsym(dlh, "ustream_ssl_ops");
 214         if (!ssl_ops)
 215                 return;
 216
 217         ssl_ctx = ssl_ops->context_new(false);
 218 }
 219
 220 static int no_ssl(const char *progname)
 221 {
 222         fprintf(stderr, "%s: SSL support not available, please install ustream-ssl\n", progname);
 223         return 1;
 224 }
 225
 226 enum {
 227         L_NO_CHECK_CERTIFICATE,
 228         L_CA_CERTIFICATE,
 229 };
 230
 231 static const struct option longopts[] = {
 232         [L_NO_CHECK_CERTIFICATE] = { "no-check-certificate", no_argument },
 233         [L_CA_CERTIFICATE] = { "ca-certificate", required_argument },
 234         {}
 235 };
 236
 237 int main(int argc, char **argv)
 238 {
 239         const char *progname = argv[0];
 240         struct uclient *cl;
 241         bool verify = true;
 242         int ch;
 243         int longopt_idx = 0;
 244
 245         init_ustream_ssl();
 246
 247         while ((ch = getopt_long(argc, argv, "qO:", longopts, &longopt_idx)) != -1) {
 248                 switch(ch) {
 249                 case 0:
 250                         switch (longopt_idx) {
 251                         case L_NO_CHECK_CERTIFICATE:
 252                                 verify = false;
 253                                 break;
 254                         case L_CA_CERTIFICATE:
 255                                 if (ssl_ctx)
 256                                         ssl_ops->context_add_ca_crt_file(ssl_ctx, optarg);
 257                                 break;
 258                         default:
 259                                 return usage(progname);
 260                         }
 261                         break;
 262                 case 'O':
 263                         output_file = optarg;
 264                         break;
 265                 case 'q':
 266                         quiet = true;
 267                         break;
 268                 default:
 269                         return usage(progname);
 270                 }
 271         }
 272
 273         argv += optind;
 274         argc -= optind;
 275
 276         if (argc != 1)
 277                 return usage(progname);
 278
 279         if (!strncmp(argv[0], "https", 5) && !ssl_ctx)
 280                 return no_ssl(progname);
 281
 282         uloop_init();
 283
 284         cl = uclient_new(argv[0], NULL, &cb);
 285         if (!cl) {
 286                 fprintf(stderr, "Failed to allocate uclient context\n");
 287                 return 1;
 288         }
 289
 290         if (ssl_ctx)
 291                 uclient_http_set_ssl_ctx(cl, ssl_ops, ssl_ctx, verify);
 292
 293         init_request(cl);
 294         uloop_run();
 295         uloop_done();
 296
 297         uclient_free(cl);
 298
 299         if (ssl_ctx)
 300                 ssl_ops->context_free(ssl_ctx);
 301
 302         return error_ret;
 303 }