src/src/transports/queuefile.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) Andrew Colin Kissa <andrew@topdog.za.net> 2016 */
   6 /* Copyright (c) University of Cambridge 2016 */
   7 /* Copyright (c) The Exim Maintainers 1995 - 2018 */
   8 /* See the file NOTICE for conditions of use and distribution. */
   9
  10
  11 #include "../exim.h"
  12 #include "queuefile.h"
  13
  14 /* Options specific to the appendfile transport. They must be in alphabetic
  15 order (note that "_" comes before the lower case letters). Some of them are
  16 stored in the publicly visible instance block - these are flagged with the
  17 opt_public flag. */
  18
  19 optionlist queuefile_transport_options[] = {
  20   { "directory", opt_stringptr,
  21     (void *)offsetof(queuefile_transport_options_block, dirname) },
  22 };
  23
  24
  25 /* Size of the options list. An extern variable has to be used so that its
  26 address can appear in the tables drtables.c. */
  27
  28 int queuefile_transport_options_count =
  29   sizeof(queuefile_transport_options) / sizeof(optionlist);
  30
  31
  32 #ifdef MACRO_PREDEF
  33
  34 /* Dummy values */
  35 queuefile_transport_options_block queuefile_transport_option_defaults = {0};
  36 void queuefile_transport_init(transport_instance *tblock) {}
  37 BOOL queuefile_transport_entry(transport_instance *tblock, address_item *addr) {return FALSE;}
  38
  39 #else   /*!MACRO_PREDEF*/
  40
  41
  42
  43 /* Default private options block for the appendfile transport. */
  44
  45 queuefile_transport_options_block queuefile_transport_option_defaults = {
  46   NULL,           /* dirname */
  47 };
  48
  49 /*************************************************
  50 *          Initialization entry point            *
  51 *************************************************/
  52
  53 void queuefile_transport_init(transport_instance *tblock)
  54 {
  55 queuefile_transport_options_block *ob =
  56   (queuefile_transport_options_block *) tblock->options_block;
  57
  58 if (!ob->dirname)
  59   log_write(0, LOG_PANIC_DIE | LOG_CONFIG,
  60     "directory must be set for the %s transport", tblock->name);
  61 }
  62
  63 /* This function will copy from a file to another
  64
  65 Arguments:
  66   dst        fd to write to (the destination queue file)
  67   src        fd to read from (the spool queue file)
  68
  69 Returns:       TRUE if all went well, FALSE otherwise with errno set
  70 */
  71
  72 static BOOL
  73 copy_spool_file(int dst, int src)
  74 {
  75 int i, j;
  76 uschar buffer[16384];
  77
  78 if (lseek(src, 0, SEEK_SET) != 0)
  79   return FALSE;
  80
  81 do
  82   if ((j = read(src, buffer, sizeof(buffer))) > 0)
  83     for (uschar * s = buffer; (i = write(dst, s, j)) != j; s += i, j -= i)
  84       if (i < 0)
  85         return FALSE;
  86   else if (j < 0)
  87     return FALSE;
  88 while (j > 0);
  89 return TRUE;
  90 }
  91
  92 /* This function performs the actual copying of the header
  93 and data files to the destination directory
  94
  95 Arguments:
  96   tb            the transport block
  97   addr          address_item being processed
  98   dstpath       destination directory name
  99   sdfd          int Source directory fd
 100   ddfd          int Destination directory fd
 101   link_file     BOOL use linkat instead of data copy
 102   srcfd         fd for data file, or -1 for header file
 103
 104 Returns:       TRUE if all went well, FALSE otherwise
 105 */
 106
 107 static BOOL
 108 copy_spool_files(transport_instance * tb, address_item * addr,
 109   const uschar * dstpath, int sdfd, int ddfd, BOOL link_file, int srcfd)
 110 {
 111 BOOL is_hdr_file = srcfd < 0;
 112 const uschar * suffix = srcfd < 0 ? US"H" : US"D";
 113 int dstfd;
 114 const uschar * filename = string_sprintf("%s-%s", message_id, suffix);
 115 const uschar * srcpath = spool_fname(US"input", message_subdir, message_id, suffix);
 116 const uschar * s, * op;
 117
 118 dstpath = string_sprintf("%s/%s-%s", dstpath, message_id, suffix);
 119
 120 if (link_file)
 121   {
 122   DEBUG(D_transport) debug_printf("%s transport, linking %s => %s\n",
 123     tb->name, srcpath, dstpath);
 124
 125   if (linkat(sdfd, CCS filename, ddfd, CCS filename, 0) >= 0)
 126     return TRUE;
 127
 128   op = US"linking";
 129   s = dstpath;
 130   }
 131 else                                    /* use data copy */
 132   {
 133   DEBUG(D_transport) debug_printf("%s transport, copying %s => %s\n",
 134     tb->name, srcpath, dstpath);
 135
 136   if (  (s = dstpath,
 137          (dstfd = openat(ddfd, CCS filename, O_RDWR|O_CREAT|O_EXCL, SPOOL_MODE))
 138          < 0
 139         )
 140      ||    is_hdr_file
 141         && (s = srcpath, (srcfd = openat(sdfd, CCS filename, O_RDONLY)) < 0)
 142      )
 143     op = US"opening";
 144
 145   else
 146     if (s = dstpath, fchmod(dstfd, SPOOL_MODE) != 0)
 147       op = US"setting perms on";
 148     else
 149       if (!copy_spool_file(dstfd, srcfd))
 150         op = US"creating";
 151       else
 152         return TRUE;
 153   }
 154
 155 addr->basic_errno = errno;
 156 addr->message = string_sprintf("%s transport %s file: %s failed with error: %s",
 157   tb->name, op, s, strerror(errno));
 158 addr->transport_return = DEFER;
 159 return FALSE;
 160 }
 161
 162 /*************************************************
 163 *              Main entry point                  *
 164 *************************************************/
 165
 166 /* This transport always returns FALSE, indicating that the status in
 167 the first address is the status for all addresses in a batch. */
 168
 169 BOOL
 170 queuefile_transport_entry(transport_instance * tblock, address_item * addr)
 171 {
 172 queuefile_transport_options_block * ob =
 173   (queuefile_transport_options_block *) tblock->options_block;
 174 BOOL can_link;
 175 uschar * sourcedir = spool_dname(US"input", message_subdir);
 176 uschar * s, * dstdir;
 177 struct stat dstatbuf, sstatbuf;
 178 int ddfd = -1, sdfd = -1;
 179
 180 DEBUG(D_transport)
 181   debug_printf("%s transport entered\n", tblock->name);
 182
 183 #ifndef O_DIRECTORY
 184 # define O_DIRECTORY 0
 185 #endif
 186 #ifndef O_NOFOLLOW
 187 # define O_NOFOLLOW 0
 188 #endif
 189
 190 if (!(dstdir = expand_string(ob->dirname)))
 191   {
 192   addr->message = string_sprintf("%s transport: failed to expand dirname option",
 193     tblock->name);
 194   addr->transport_return = DEFER;
 195   return FALSE;
 196   }
 197 if (*dstdir != '/')
 198   {
 199   addr->transport_return = PANIC;
 200   addr->message = string_sprintf("%s transport directory: "
 201     "%s is not absolute", tblock->name, dstdir);
 202   return FALSE;
 203   }
 204
 205 /* Open the source and destination directories and check if they are
 206 on the same filesystem, so we can hard-link files rather than copying. */
 207
 208 if (  (s = dstdir,
 209        (ddfd = Uopen(s, O_RDONLY | O_DIRECTORY | O_NOFOLLOW, 0)) < 0)
 210    || (s = sourcedir,
 211        (sdfd = Uopen(sourcedir, O_RDONLY | O_DIRECTORY | O_NOFOLLOW, 0)) < 0)
 212    )
 213   {
 214   addr->transport_return = PANIC;
 215   addr->basic_errno = errno;
 216   addr->message = string_sprintf("%s transport accessing directory: %s "
 217     "failed with error: %s", tblock->name, s, strerror(errno));
 218   if (ddfd >= 0) (void) close(ddfd);
 219   return FALSE;
 220   }
 221
 222 if (  (s = dstdir,    fstat(ddfd, &dstatbuf) < 0)
 223    || (s = sourcedir, fstat(sdfd, &sstatbuf) < 0)
 224    )
 225   {
 226   addr->transport_return = PANIC;
 227   addr->basic_errno = errno;
 228   addr->message = string_sprintf("%s transport fstat on directory fd: "
 229     "%s failed with error: %s", tblock->name, s, strerror(errno));
 230   goto RETURN;
 231   }
 232 can_link = (dstatbuf.st_dev == sstatbuf.st_dev);
 233
 234 if (f.dont_deliver)
 235   {
 236   DEBUG(D_transport)
 237     debug_printf("*** delivery by %s transport bypassed by -N option\n",
 238       tblock->name);
 239   addr->transport_return = OK;
 240   goto RETURN;
 241   }
 242
 243 /* Link or copy the header and data spool files */
 244
 245 DEBUG(D_transport)
 246   debug_printf("%s transport, copying header file\n", tblock->name);
 247
 248 if (!copy_spool_files(tblock, addr, dstdir, sdfd, ddfd, can_link, -1))
 249   goto RETURN;
 250
 251 DEBUG(D_transport)
 252   debug_printf("%s transport, copying data file\n", tblock->name);
 253
 254 if (!copy_spool_files(tblock, addr, dstdir, sdfd, ddfd, can_link,
 255         deliver_datafile))
 256   {
 257   DEBUG(D_transport)
 258     debug_printf("%s transport, copying data file failed, "
 259       "unlinking the header file\n", tblock->name);
 260   Uunlink(string_sprintf("%s/%s-H", dstdir, message_id));
 261   goto RETURN;
 262   }
 263
 264 DEBUG(D_transport)
 265   debug_printf("%s transport succeeded\n", tblock->name);
 266
 267 addr->transport_return = OK;
 268
 269 RETURN:
 270 if (ddfd >= 0) (void) close(ddfd);
 271 if (sdfd >= 0) (void) close(sdfd);
 272
 273 /* A return of FALSE means that if there was an error, a common error was
 274 put in the first address of a batch. */
 275 return FALSE;
 276 }
 277
 278 #endif /*!MACRO_PREDEF*/