uftps.h

   1 /*
   2  * User FTP Server,  Share folders over FTP without being root.
   3  * Copyright (C) 2008  Isaac Jurado
   4  *
   5  * This program is free software; you can redistribute it and/or modify it under
   6  * the terms of the GNU General Public License as published by the Free Software
   7  * Foundation; either version 2 of the License, or (at your option) any later
   8  * version.
   9  *
  10  * This program is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  12  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  13  * details.
  14  *
  15  * You should have received a copy of the GNU General Public License along with
  16  * this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
  18  */
  19
  20 /*
  21  * Large file support.
  22  */
  23 #define _FILE_OFFSET_BITS   64
  24 #define _LARGEFILE_SOURCE
  25 #define _LARGEFILE64_SOURCE
  26
  27 /*
  28  * Hasefroch requirements.  No need to inclose within "#ifdef" as no other
  29  * system cares about these definitions.
  30  */
  31 #define WINVER              0x0501
  32 #define __MSVCRT_VERSION__  0x0601
  33 #define _NO_OLDNAMES
  34
  35 /*
  36  * Early multiplaform support (more details on hase.h).
  37  */
  38 #include <sys/types.h>
  39 #ifdef __MINGW32__
  40 #  include <winsock2.h>
  41    typedef __int64 off_t;
  42    typedef int socklen_t;
  43 #  define CCP_CAST  (const char *)
  44 #else
  45 #  include <netinet/in.h>
  46 #  define closesocket(s)  close(s)
  47 #  define CCP_CAST
  48 #endif
  49
  50 /*
  51  * Attributes help to catch silly mistakes, but they are not always available.
  52  */
  53 #if !defined(__GNUC__) && !defined(__MINGW32__)
  54 #  define __attribute__(x)
  55 #endif
  56
  57 /*
  58  * Constants.
  59  */
  60 #define DEFAULT_PORT 2211
  61 #define LINE_SIZE    4096  /* Same value as PATH_MAX */
  62
  63 /*
  64  * Recognized commands.
  65  */
  66 enum command
  67 {
  68         FTP_NONE = 0,
  69         FTP_ABOR, FTP_ACCT, FTP_ALLO, FTP_APPE, FTP_CDUP, FTP_CWD,  FTP_DELE,
  70         FTP_FEAT, FTP_HELP, FTP_LIST, FTP_MDTM, FTP_MKD,  FTP_MODE, FTP_NLST,
  71         FTP_NOOP, FTP_OPTS, FTP_PASS, FTP_PASV, FTP_PORT, FTP_PWD,  FTP_QUIT,
  72         FTP_REIN, FTP_REST, FTP_RETR, FTP_RMD,  FTP_RNFR, FTP_RNTO, FTP_SITE,
  73         FTP_SIZE, FTP_SMNT, FTP_STAT, FTP_STOR, FTP_STOU, FTP_STRU, FTP_SYST,
  74         FTP_TYPE, FTP_USER
  75 };
  76
  77 /*
  78  * Data channel modes.
  79  */
  80 enum data_mode
  81 {
  82         DEFAULT_MODE,  /* RFC default, unimplemented/unsupported */
  83         ACTIVE_MODE,   /* Active mode enabled with PORT requests */
  84         PASSIVE_MODE   /* Passive mode enabled with PASV requests */
  85 };
  86
  87 /*
  88  * Session (client) state.
  89  */
  90 struct _SessionScope
  91 {
  92         /* Sockets */
  93         int  control_sk;    /* Control channel */
  94         int  data_sk;       /* Data channel */
  95         int  passive_sk;    /* Server socket for passive mode */
  96
  97         /* Buffer offsets and fill counters */
  98         int  input_offset;  /* Input buffer data offset */
  99         int  input_len;     /* Bytes in input buffer */
 100         int  cwd_len;       /* Length of current working directory */
 101
 102         /* Misc state information */
 103         int             pid;          /* Cached Process ID */
 104         enum data_mode  mode;         /* Current data channel mode */
 105         off_t           file_offset;  /* Last REST offset accepted */
 106         char           *arg;          /* Pointer to comand line argument */
 107
 108         /* Session addresses */
 109         struct sockaddr_in  port_destination;  /* Parsed PORT argument */
 110         struct sockaddr_in  local_address;     /* Control local IP */
 111         struct sockaddr_in  client_address;    /* Control peer IP */
 112
 113         /* Buffers */
 114         char  input[LINE_SIZE];  /* Incoming command buffer */
 115         char  aux[LINE_SIZE];    /* Auxiliary buffer */
 116         char  cwd[LINE_SIZE];    /* Current Working Directory */
 117 };
 118
 119 extern struct _SessionScope  SS;  /* SS --> Session State */
 120
 121
 122 /*
 123  * Logging functions.  These functions are implemented in log.c
 124  */
 125 #ifdef DEBUG
 126 #  define assert(cond)  if (!(cond)) warning("Assertion '" #cond "' failed")
 127    void debug (const char *, ...) __attribute__((format(printf,1,2)));
 128 #else
 129 #  define assert(cond)
 130    static inline void debug (const char *msg, ...) {}
 131 #endif
 132
 133 /*
 134  * These functions will be replaced by variadic macros when compilers other than
 135  * GCC can be tested.
 136  */
 137 void notice  (const char *, ...) __attribute__((format(printf,1,2)));
 138 void warning (const char *, ...) __attribute__((format(printf,1,2)));
 139 void error   (const char *, ...) __attribute__((format(printf,1,2)));
 140 void fatal   (const char *, ...) __attribute__((format(printf,1,2), noreturn));
 141
 142
 143 /*
 144  * Reply functions, used to send data over the control and data channels
 145  * respectively.  Implemented in reply.c.
 146  */
 147 void reply      (const char *, int);
 148 int  data_reply (const char *, int);
 149
 150
 151 /*
 152  * Other functions.  Each function declared here is implemented in a separate
 153  * file, with the same name as the function.  Functions sorted alphabetically.
 154  */
 155 void         change_dir          (void);
 156 void         command_loop        (void)  __attribute__((noreturn));
 157 void         enable_passive      (void);
 158 int          expand_arg          (void);
 159 void         file_stats          (int);
 160 void         init_session        (int);
 161 void         list_dir            (int);
 162 enum command next_command        (void);
 163 int          open_data_channel   (void);
 164 int          open_file           (off_t *);
 165 void         parse_port_argument (void);
 166 void         send_file           (void);
 167
 168
 169 /*
 170  * Utility macro to call reply() with a constant string.  At compile time, the
 171  * length of these strings is known.
 172  */
 173 #define reply_c(str)  reply(str, sizeof(str) - 1)
 174