release/src/router/busybox/networking/ftpgetput.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * ftpget
   4  *
   5  * Mini implementation of FTP to retrieve a remote file.
   6  *
   7  * Copyright (C) 2002 Jeff Angielski, The PTR Group <jeff@theptrgroup.com>
   8  * Copyright (C) 2002 Glenn McGrath
   9  *
  10  * Based on wget.c by Chip Rosenthal Covad Communications
  11  * <chip@laserlink.net>
  12  *
  13  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  14  */
  15
  16 #include "libbb.h"
  17
  18 struct globals {
  19         const char *user;
  20         const char *password;
  21         struct len_and_sockaddr *lsa;
  22         FILE *control_stream;
  23         int verbose_flag;
  24         int do_continue;
  25         char buf[1]; /* actually [BUFSZ] */
  26 };
  27 #define G (*(struct globals*)&bb_common_bufsiz1)
  28 enum { BUFSZ = COMMON_BUFSIZE - offsetof(struct globals, buf) };
  29 struct BUG_G_too_big {
  30         char BUG_G_too_big[sizeof(G) <= COMMON_BUFSIZE ? 1 : -1];
  31 };
  32 #define user           (G.user          )
  33 #define password       (G.password      )
  34 #define lsa            (G.lsa           )
  35 #define control_stream (G.control_stream)
  36 #define verbose_flag   (G.verbose_flag  )
  37 #define do_continue    (G.do_continue   )
  38 #define buf            (G.buf           )
  39 #define INIT_G() do { } while (0)
  40
  41
  42 static void ftp_die(const char *msg) NORETURN;
  43 static void ftp_die(const char *msg)
  44 {
  45         char *cp = buf; /* buf holds peer's response */
  46
  47         /* Guard against garbage from remote server */
  48         while (*cp >= ' ' && *cp < '\x7f')
  49                 cp++;
  50         *cp = '\0';
  51         bb_error_msg_and_die("unexpected server response%s%s: %s",
  52                         (msg ? " to " : ""), (msg ? msg : ""), buf);
  53 }
  54
  55 static int ftpcmd(const char *s1, const char *s2)
  56 {
  57         unsigned n;
  58
  59         if (verbose_flag) {
  60                 bb_error_msg("cmd %s %s", s1, s2);
  61         }
  62
  63         if (s1) {
  64                 fprintf(control_stream, (s2 ? "%s %s\r\n" : "%s %s\r\n"+3),
  65                                                 s1, s2);
  66                 fflush(control_stream);
  67         }
  68
  69         do {
  70                 strcpy(buf, "EOF");
  71                 if (fgets(buf, BUFSZ - 2, control_stream) == NULL) {
  72                         ftp_die(NULL);
  73                 }
  74         } while (!isdigit(buf[0]) || buf[3] != ' ');
  75
  76         buf[3] = '\0';
  77         n = xatou(buf);
  78         buf[3] = ' ';
  79         return n;
  80 }
  81
  82 static void ftp_login(void)
  83 {
  84         /* Connect to the command socket */
  85         control_stream = fdopen(xconnect_stream(lsa), "r+");
  86         if (control_stream == NULL) {
  87                 /* fdopen failed - extremely unlikely */
  88                 bb_perror_nomsg_and_die();
  89         }
  90
  91         if (ftpcmd(NULL, NULL) != 220) {
  92                 ftp_die(NULL);
  93         }
  94
  95         /*  Login to the server */
  96         switch (ftpcmd("USER", user)) {
  97         case 230:
  98                 break;
  99         case 331:
 100                 if (ftpcmd("PASS", password) != 230) {
 101                         ftp_die("PASS");
 102                 }
 103                 break;
 104         default:
 105                 ftp_die("USER");
 106         }
 107
 108         ftpcmd("TYPE I", NULL);
 109 }
 110
 111 static int xconnect_ftpdata(void)
 112 {
 113         char *buf_ptr;
 114         unsigned port_num;
 115
 116 /*
 117 TODO: PASV command will not work for IPv6. RFC2428 describes
 118 IPv6-capable "extended PASV" - EPSV.
 119
 120 "EPSV [protocol]" asks server to bind to and listen on a data port
 121 in specified protocol. Protocol is 1 for IPv4, 2 for IPv6.
 122 If not specified, defaults to "same as used for control connection".
 123 If server understood you, it should answer "229 <some text>(|||port|)"
 124 where "|" are literal pipe chars and "port" is ASCII decimal port#.
 125
 126 There is also an IPv6-capable replacement for PORT (EPRT),
 127 but we don't need that.
 128
 129 NB: PASV may still work for some servers even over IPv6.
 130 For example, vsftp happily answers
 131 "227 Entering Passive Mode (0,0,0,0,n,n)" and proceeds as usual.
 132
 133 TODO2: need to stop ignoring IP address in PASV response.
 134 */
 135
 136         if (ftpcmd("PASV", NULL) != 227) {
 137                 ftp_die("PASV");
 138         }
 139
 140         /* Response is "NNN garbageN1,N2,N3,N4,P1,P2[)garbage]
 141          * Server's IP is N1.N2.N3.N4 (we ignore it)
 142          * Server's port for data connection is P1*256+P2 */
 143         buf_ptr = strrchr(buf, ')');
 144         if (buf_ptr) *buf_ptr = '\0';
 145
 146         buf_ptr = strrchr(buf, ',');
 147         *buf_ptr = '\0';
 148         port_num = xatoul_range(buf_ptr + 1, 0, 255);
 149
 150         buf_ptr = strrchr(buf, ',');
 151         *buf_ptr = '\0';
 152         port_num += xatoul_range(buf_ptr + 1, 0, 255) * 256;
 153
 154         set_nport(lsa, htons(port_num));
 155         return xconnect_stream(lsa);
 156 }
 157
 158 static int pump_data_and_QUIT(int from, int to)
 159 {
 160         /* copy the file */
 161         if (bb_copyfd_eof(from, to) == -1) {
 162                 /* error msg is already printed by bb_copyfd_eof */
 163                 return EXIT_FAILURE;
 164         }
 165
 166         /* close data connection */
 167         close(from); /* don't know which one is that, so we close both */
 168         close(to);
 169
 170         /* does server confirm that transfer is finished? */
 171         if (ftpcmd(NULL, NULL) != 226) {
 172                 ftp_die(NULL);
 173         }
 174         ftpcmd("QUIT", NULL);
 175
 176         return EXIT_SUCCESS;
 177 }
 178
 179 #if !ENABLE_FTPGET
 180 int ftp_receive(const char *local_path, char *server_path);
 181 #else
 182 static
 183 int ftp_receive(const char *local_path, char *server_path)
 184 {
 185         int fd_data;
 186         int fd_local = -1;
 187         off_t beg_range = 0;
 188
 189         /* connect to the data socket */
 190         fd_data = xconnect_ftpdata();
 191
 192         if (ftpcmd("SIZE", server_path) != 213) {
 193                 do_continue = 0;
 194         }
 195
 196         if (LONE_DASH(local_path)) {
 197                 fd_local = STDOUT_FILENO;
 198                 do_continue = 0;
 199         }
 200
 201         if (do_continue) {
 202                 struct stat sbuf;
 203                 /* lstat would be wrong here! */
 204                 if (stat(local_path, &sbuf) < 0) {
 205                         bb_perror_msg_and_die("stat");
 206                 }
 207                 if (sbuf.st_size > 0) {
 208                         beg_range = sbuf.st_size;
 209                 } else {
 210                         do_continue = 0;
 211                 }
 212         }
 213
 214         if (do_continue) {
 215                 sprintf(buf, "REST %"OFF_FMT"d", beg_range);
 216                 if (ftpcmd(buf, NULL) != 350) {
 217                         do_continue = 0;
 218                 }
 219         }
 220
 221         if (ftpcmd("RETR", server_path) > 150) {
 222                 ftp_die("RETR");
 223         }
 224
 225         /* create local file _after_ we know that remote file exists */
 226         if (fd_local == -1) {
 227                 fd_local = xopen(local_path,
 228                         do_continue ? (O_APPEND | O_WRONLY)
 229                                     : (O_CREAT | O_TRUNC | O_WRONLY)
 230                 );
 231         }
 232
 233         return pump_data_and_QUIT(fd_data, fd_local);
 234 }
 235 #endif
 236
 237 #if !ENABLE_FTPPUT
 238 int ftp_send(const char *server_path, char *local_path);
 239 #else
 240 static
 241 int ftp_send(const char *server_path, char *local_path)
 242 {
 243         int fd_data;
 244         int fd_local;
 245         int response;
 246
 247         /* connect to the data socket */
 248         fd_data = xconnect_ftpdata();
 249
 250         /* get the local file */
 251         fd_local = STDIN_FILENO;
 252         if (NOT_LONE_DASH(local_path))
 253                 fd_local = xopen(local_path, O_RDONLY);
 254
 255         response = ftpcmd("STOR", server_path);
 256         switch (response) {
 257         case 125:
 258         case 150:
 259                 break;
 260         default:
 261                 ftp_die("STOR");
 262         }
 263
 264         return pump_data_and_QUIT(fd_local, fd_data);
 265 }
 266 #endif
 267
 268 #if ENABLE_FEATURE_FTPGETPUT_LONG_OPTIONS
 269 static const char ftpgetput_longopts[] ALIGN1 =
 270         "continue\0" Required_argument "c"
 271         "verbose\0"  No_argument       "v"
 272         "username\0" Required_argument "u"
 273         "password\0" Required_argument "p"
 274         "port\0"     Required_argument "P"
 275         ;
 276 #endif
 277
 278 int ftpgetput_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 279 int ftpgetput_main(int argc UNUSED_PARAM, char **argv)
 280 {
 281         unsigned opt;
 282         const char *port = "ftp";
 283         /* socket to ftp server */
 284
 285 #if ENABLE_FTPPUT && !ENABLE_FTPGET
 286 # define ftp_action ftp_send
 287 #elif ENABLE_FTPGET && !ENABLE_FTPPUT
 288 # define ftp_action ftp_receive
 289 #else
 290         int (*ftp_action)(const char *, char *) = ftp_send;
 291
 292         /* Check to see if the command is ftpget or ftput */
 293         if (applet_name[3] == 'g') {
 294                 ftp_action = ftp_receive;
 295         }
 296 #endif
 297
 298         INIT_G();
 299         /* Set default values */
 300         user = "anonymous";
 301         password = "busybox@";
 302
 303         /*
 304          * Decipher the command line
 305          */
 306 #if ENABLE_FEATURE_FTPGETPUT_LONG_OPTIONS
 307         applet_long_options = ftpgetput_longopts;
 308 #endif
 309         opt_complementary = "=3:vv:cc"; /* must have 3 params; -v and -c count */
 310         opt = getopt32(argv, "cvu:p:P:", &user, &password, &port,
 311                                         &verbose_flag, &do_continue);
 312         argv += optind;
 313
 314         /* We want to do exactly _one_ DNS lookup, since some
 315          * sites (i.e. ftp.us.debian.org) use round-robin DNS
 316          * and we want to connect to only one IP... */
 317         lsa = xhost2sockaddr(argv[0], bb_lookup_port(port, "tcp", 21));
 318         if (verbose_flag) {
 319                 printf("Connecting to %s (%s)\n", argv[0],
 320                         xmalloc_sockaddr2dotted(&lsa->u.sa));
 321         }
 322
 323         ftp_login();
 324         return ftp_action(argv[1], argv[2]);
 325 }