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  * Common definitions.
  22  */
  23
  24 /* Large file support */
  25 #define _FILE_OFFSET_BITS   64
  26 #define _LARGEFILE_SOURCE
  27 #define _LARGEFILE64_SOURCE
  28
  29 #include <sys/types.h>
  30 #include <netinet/in.h>
  31
  32 /* Attributes help to catch silly mistakes, but they are not always available */
  33 #ifndef __GNUC__
  34 #  define __attribute__(x)
  35 #endif
  36
  37 /* Constants */
  38 #define DEFAULT_PORT 2211
  39 #define LINE_SIZE    4096  /* Same value as PATH_MAX */
  40
  41 /* Recognized commands */
  42 enum command
  43 {
  44         FTP_NONE = 0,
  45         FTP_ABOR, FTP_ACCT, FTP_ALLO, FTP_APPE, FTP_CDUP, FTP_CWD,  FTP_DELE,
  46         FTP_FEAT, FTP_HELP, FTP_LIST, FTP_MDTM, FTP_MKD,  FTP_MODE, FTP_NLST,
  47         FTP_NOOP, FTP_OPTS, FTP_PASS, FTP_PASV, FTP_PORT, FTP_PWD,  FTP_QUIT,
  48         FTP_REIN, FTP_REST, FTP_RETR, FTP_RMD,  FTP_RNFR, FTP_RNTO, FTP_SITE,
  49         FTP_SIZE, FTP_SMNT, FTP_STAT, FTP_STOR, FTP_STOU, FTP_STRU, FTP_SYST,
  50         FTP_TYPE, FTP_USER
  51 };
  52
  53 /* Data channel modes */
  54 enum data_mode
  55 {
  56         DEFAULT_MODE,  /* RFC default, unimplemented/unsupported */
  57         ACTIVE_MODE,   /* Active mode enabled with PORT requests */
  58         PASSIVE_MODE   /* Passive mode enabled with PASV requests */
  59 };
  60
  61 /* Session (client) state */
  62 struct _SessionScope
  63 {
  64         /* Sockets */
  65         int  control_sk;    /* Control channel */
  66         int  data_sk;       /* Data channel */
  67         int  passive_sk;    /* Server socket for passive mode */
  68
  69         /* Buffer offsets and fill counters */
  70         int  input_offset;  /* Input buffer data offset */
  71         int  input_len;     /* Bytes in input buffer */
  72         int  cwd_len;       /* Length of current working directory */
  73
  74         /* Misc state information */
  75         enum data_mode  mode;         /* Current data channel mode */
  76         off_t           file_offset;  /* Last REST offset accepted */
  77         char           *arg;          /* Pointer to comand line argument */
  78
  79         /* Session addresses */
  80         struct sockaddr_in  port_destination;  /* Parsed PORT argument */
  81         struct sockaddr_in  local_address;     /* Control local IP */
  82         struct sockaddr_in  client_address;    /* Control peer IP */
  83
  84         /* Buffers */
  85         char  input[LINE_SIZE];  /* Incoming command buffer */
  86         char  aux[LINE_SIZE];    /* Auxiliary buffer */
  87         char  cwd[LINE_SIZE];    /* Current Working Directory */
  88 };
  89
  90 extern struct _SessionScope  SS;  /* SS --> Session State */
  91
  92
  93 /*
  94  * Logging functions.  These functions are implemented in log.c
  95  */
  96 #ifdef DEBUG
  97 #  define assert(cond)  if (!(cond)) warning("Assertion '" #cond "' failed")
  98    void debug (const char *, ...) __attribute__((format(printf,1,2)));
  99 #else
 100 #  define assert(cond)
 101    static inline void debug (const char *msg, ...) {}
 102 #endif
 103
 104 /*
 105  * These functions will be replaced by variadic macros when compilers other than
 106  * GCC can be tested.
 107  */
 108 void notice  (const char *, ...) __attribute__((format(printf,1,2)));
 109 void warning (const char *, ...) __attribute__((format(printf,1,2)));
 110 void error   (const char *, ...) __attribute__((format(printf,1,2)));
 111 void fatal   (const char *, ...) __attribute__((format(printf,1,2), noreturn));
 112
 113
 114 /*
 115  * Reply functions, used to send data over the control and data channels
 116  * respectively.  Implemented in reply.c.
 117  */
 118 void reply      (const char *, int);
 119 int  data_reply (const char *, int);
 120
 121
 122 /*
 123  * Other functions.  Each function declared here is implemented in a separate
 124  * file, with the same name as the function.  Functions sorted alphabetically.
 125  */
 126 void         change_dir          (void);
 127 void         command_loop        (void)  __attribute__((noreturn));
 128 void         enable_passive      (void);
 129 int          expand_arg          (void);
 130 void         file_stats          (int);
 131 void         init_session        (int);
 132 void         list_dir            (int);
 133 enum command next_command        (void);
 134 int          open_data_channel   (void);
 135 int          open_file           (off_t *);
 136 void         parse_port_argument (void);
 137 void         send_file           (void);
 138
 139
 140 /*
 141  * Utility macro to call reply() with a constant string.  At compile time, the
 142  * length of these strings is known.
 143  */
 144 #define reply_c(str)  reply(str, sizeof(str) - 1)
 145