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         if (output_fd >= 0) {
  89                 close(output_fd);
  90                 output_fd = -1;
  91         }
  92         uclient_disconnect(cl);
  93         uloop_end();
  94 }
  95
  96 static void example_header_done(struct uclient *cl)
  97 {
  98         static int retries;
  99
 100         struct blob_attr *cur;
 101         int rem;
 102
 103         if (retries < 10 && uclient_http_redirect(cl)) {
 104                 if (!quiet)
 105                         fprintf(stderr, "Redirected to %s on %s\n", cl->url->location, cl->url->host);
 106
 107                 retries++;
 108                 return;
 109         }
 110
 111         retries = 0;
 112         if (!quiet) {
 113                 fprintf(stderr, "Headers (%d): \n", cl->status_code);
 114                 blobmsg_for_each_attr(cur, cl->meta, rem) {
 115                         fprintf(stderr, "%s=%s\n", blobmsg_name(cur), (char *) blobmsg_data(cur));
 116                 }
 117         }
 118
 119         switch (cl->status_code) {
 120         case 204:
 121         case 200:
 122                 output_fd = open_output_file(cl->url->location, true);
 123                 if (output_fd < 0) {
 124                         if (!quiet)
 125                                 perror("Cannot open output file");
 126                         error_ret = 3;
 127                         request_done(cl);
 128                 }
 129                 break;
 130
 131         default:
 132                 request_done(cl);
 133                 break;
 134         }
 135 }
 136
 137 static void example_read_data(struct uclient *cl)
 138 {
 139         char buf[256];
 140         int len;
 141
 142         if (output_fd < 0)
 143                 return;
 144
 145         while (1) {
 146                 len = uclient_read(cl, buf, sizeof(buf));
 147                 if (!len)
 148                         return;
 149
 150                 write(output_fd, buf, len);
 151         }
 152 }
 153
 154 static void msg_connecting(struct uclient *cl)
 155 {
 156         char addr[INET6_ADDRSTRLEN];
 157         int port;
 158
 159         if (quiet)
 160                 return;
 161
 162         uclient_get_addr(addr, &port, &cl->remote_addr);
 163         fprintf(stderr, "Connecting to %s %s:%d\n", cl->url->host, addr, port);
 164 }
 165
 166 static void init_request(struct uclient *cl)
 167 {
 168         uclient_connect(cl);
 169         msg_connecting(cl);
 170         uclient_http_set_request_type(cl, "GET");
 171         uclient_request(cl);
 172 }
 173
 174 static void example_eof(struct uclient *cl)
 175 {
 176         request_done(cl);
 177 }
 178
 179 static void example_error(struct uclient *cl, int code)
 180 {
 181         if (!quiet)
 182                 fprintf(stderr, "Error %d!\n", code);
 183
 184         request_done(cl);
 185 }
 186
 187 static const struct uclient_cb cb = {
 188         .header_done = example_header_done,
 189         .data_read = example_read_data,
 190         .data_eof = example_eof,
 191         .error = example_error,
 192 };
 193
 194 static int usage(const char *progname)
 195 {
 196         fprintf(stderr,
 197                 "Usage: %s [options] <URL>\n"
 198                 "Options:\n"
 199                 "       -O <file>:                      Redirect output to file (use \"-\" for stdout)\n"
 200                 "\n"
 201                 "HTTPS options:\n"
 202                 "       --ca-certificate=<cert>:        Load CA certificates from file <cert>\n"
 203                 "       --no-check-certificate:         don't validate the server's certificate\n"
 204                 "\n", progname);
 205         return 1;
 206 }
 207
 208
 209 static void init_ustream_ssl(void)
 210 {
 211         void *dlh;
 212
 213         dlh = dlopen("libustream-ssl." LIB_EXT, RTLD_LAZY | RTLD_LOCAL);
 214         if (!dlh)
 215                 return;
 216
 217         ssl_ops = dlsym(dlh, "ustream_ssl_ops");
 218         if (!ssl_ops)
 219                 return;
 220
 221         ssl_ctx = ssl_ops->context_new(false);
 222 }
 223
 224 static int no_ssl(const char *progname)
 225 {
 226         fprintf(stderr, "%s: SSL support not available, please install ustream-ssl\n", progname);
 227         return 1;
 228 }
 229
 230 enum {
 231         L_NO_CHECK_CERTIFICATE,
 232         L_CA_CERTIFICATE,
 233 };
 234
 235 static const struct option longopts[] = {
 236         [L_NO_CHECK_CERTIFICATE] = { "no-check-certificate", no_argument },
 237         [L_CA_CERTIFICATE] = { "ca-certificate", required_argument },
 238         {}
 239 };
 240
 241 int main(int argc, char **argv)
 242 {
 243         const char *progname = argv[0];
 244         struct uclient *cl;
 245         bool verify = true;
 246         int ch;
 247         int longopt_idx = 0;
 248
 249         init_ustream_ssl();
 250
 251         while ((ch = getopt_long(argc, argv, "qO:", longopts, &longopt_idx)) != -1) {
 252                 switch(ch) {
 253                 case 0:
 254                         switch (longopt_idx) {
 255                         case L_NO_CHECK_CERTIFICATE:
 256                                 verify = false;
 257                                 break;
 258                         case L_CA_CERTIFICATE:
 259                                 if (ssl_ctx)
 260                                         ssl_ops->context_add_ca_crt_file(ssl_ctx, optarg);
 261                                 break;
 262                         default:
 263                                 return usage(progname);
 264                         }
 265                         break;
 266                 case 'O':
 267                         output_file = optarg;
 268                         break;
 269                 case 'q':
 270                         quiet = true;
 271                         break;
 272                 default:
 273                         return usage(progname);
 274                 }
 275         }
 276
 277         argv += optind;
 278         argc -= optind;
 279
 280         if (argc != 1)
 281                 return usage(progname);
 282
 283         if (!strncmp(argv[0], "https", 5) && !ssl_ctx)
 284                 return no_ssl(progname);
 285
 286         uloop_init();
 287
 288         cl = uclient_new(argv[0], NULL, &cb);
 289         if (!cl) {
 290                 fprintf(stderr, "Failed to allocate uclient context\n");
 291                 return 1;
 292         }
 293
 294         if (ssl_ctx)
 295                 uclient_http_set_ssl_ctx(cl, ssl_ops, ssl_ctx, verify);
 296
 297         init_request(cl);
 298         uloop_run();
 299         uloop_done();
 300
 301         uclient_free(cl);
 302
 303         if (ssl_ctx)
 304                 ssl_ops->context_free(ssl_ctx);
 305
 306         return error_ret;
 307 }