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