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 2017 */
   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 uschar * s;
  78
  79 if (lseek(src, 0, SEEK_SET) != 0)
  80   return FALSE;
  81
  82 do
  83   if ((j = read(src, buffer, sizeof(buffer))) > 0)
  84     for (s = buffer; (i = write(dst, s, j)) != j; s += i, j -= i)
  85       if (i < 0)
  86         return FALSE;
  87   else if (j < 0)
  88     return FALSE;
  89 while (j > 0);
  90 return TRUE;
  91 }
  92
  93 /* This function performs the actual copying of the header
  94 and data files to the destination directory
  95
  96 Arguments:
  97   tb            the transport block
  98   addr          address_item being processed
  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   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 * dstpath = string_sprintf("%s/%s-%s",
 117   ((queuefile_transport_options_block *) tb->options_block)->dirname,
 118   message_id, suffix);
 119 const uschar * s;
 120 const uschar * op;
 121
 122 if (link_file)
 123   {
 124   DEBUG(D_transport) debug_printf("%s transport, linking %s => %s\n",
 125     tb->name, srcpath, dstpath);
 126
 127   if (linkat(sdfd, CCS filename, ddfd, CCS filename, 0) >= 0)
 128     return TRUE;
 129
 130   op = US"linking";
 131   s = dstpath;
 132   }
 133 else                                    /* use data copy */
 134   {
 135   DEBUG(D_transport) debug_printf("%s transport, copying %s => %s\n",
 136     tb->name, srcpath, dstpath);
 137
 138   if (  (s = dstpath,
 139          (dstfd = openat(ddfd, CCS filename, O_RDWR|O_CREAT|O_EXCL, SPOOL_MODE))
 140          < 0
 141         )
 142      ||    is_hdr_file
 143         && (s = srcpath, (srcfd = openat(sdfd, CCS filename, O_RDONLY)) < 0)
 144      )
 145     op = US"opening";
 146
 147   else
 148     if (s = dstpath, fchmod(dstfd, SPOOL_MODE) != 0)
 149       op = US"setting perms on";
 150     else
 151       if (!copy_spool_file(dstfd, srcfd))
 152         op = US"creating";
 153       else
 154         return TRUE;
 155   }
 156
 157 addr->basic_errno = errno;
 158 addr->message = string_sprintf("%s transport %s file: %s failed with error: %s",
 159   tb->name, op, s, strerror(errno));
 160 addr->transport_return = DEFER;
 161 return FALSE;
 162 }
 163
 164 /*************************************************
 165 *              Main entry point                  *
 166 *************************************************/
 167
 168 /* This transport always returns FALSE, indicating that the status in
 169 the first address is the status for all addresses in a batch. */
 170
 171 BOOL
 172 queuefile_transport_entry(transport_instance * tblock, address_item * addr)
 173 {
 174 queuefile_transport_options_block * ob =
 175   (queuefile_transport_options_block *) tblock->options_block;
 176 BOOL can_link;
 177 uschar * sourcedir = spool_dname(US"input", message_subdir);
 178 uschar * s;
 179 struct stat dstatbuf, sstatbuf;
 180 int ddfd = -1, sdfd = -1;
 181
 182 DEBUG(D_transport)
 183   debug_printf("%s transport entered\n", tblock->name);
 184
 185 #ifndef O_DIRECTORY
 186 # define O_DIRECTORY 0
 187 #endif
 188 #ifndef O_NOFOLLOW
 189 # define O_NOFOLLOW 0
 190 #endif
 191
 192 if (ob->dirname[0] != '/')
 193   {
 194   addr->transport_return = PANIC;
 195   addr->message = string_sprintf("%s transport directory: "
 196     "%s is not absolute", tblock->name, ob->dirname);
 197   return FALSE;
 198   }
 199
 200 /* Open the source and destination directories and check if they are
 201 on the same filesystem, so we can hard-link files rather than copying. */
 202
 203 if (  (s = ob->dirname,
 204        (ddfd = Uopen(s, O_RDONLY | O_DIRECTORY | O_NOFOLLOW, 0)) < 0)
 205    || (s = sourcedir,
 206        (sdfd = Uopen(sourcedir, O_RDONLY | O_DIRECTORY | O_NOFOLLOW, 0)) < 0)
 207    )
 208   {
 209   addr->transport_return = PANIC;
 210   addr->basic_errno = errno;
 211   addr->message = string_sprintf("%s transport accessing directory: %s "
 212     "failed with error: %s", tblock->name, s, strerror(errno));
 213   if (ddfd >= 0) (void) close(ddfd);
 214   return FALSE;
 215   }
 216
 217 if (  (s = ob->dirname, fstat(ddfd, &dstatbuf) < 0)
 218    || (s = sourcedir,   fstat(sdfd, &sstatbuf) < 0)
 219    )
 220   {
 221   addr->transport_return = PANIC;
 222   addr->basic_errno = errno;
 223   addr->message = string_sprintf("%s transport fstat on directory fd: "
 224     "%s failed with error: %s", tblock->name, s, strerror(errno));
 225   goto RETURN;
 226   }
 227 can_link = (dstatbuf.st_dev == sstatbuf.st_dev);
 228
 229 if (dont_deliver)
 230   {
 231   DEBUG(D_transport)
 232     debug_printf("*** delivery by %s transport bypassed by -N option\n",
 233       tblock->name);
 234   addr->transport_return = OK;
 235   goto RETURN;
 236   }
 237
 238 /* Link or copy the header and data spool files */
 239
 240 DEBUG(D_transport)
 241   debug_printf("%s transport, copying header file\n", tblock->name);
 242
 243 if (!copy_spool_files(tblock, addr, sdfd, ddfd, can_link, -1))
 244   goto RETURN;
 245
 246 DEBUG(D_transport)
 247   debug_printf("%s transport, copying data file\n", tblock->name);
 248
 249 if (!copy_spool_files(tblock, addr, sdfd, ddfd, can_link, deliver_datafile))
 250   {
 251   DEBUG(D_transport)
 252     debug_printf("%s transport, copying data file failed, "
 253       "unlinking the header file\n", tblock->name);
 254   Uunlink(string_sprintf("%s/%s-H", ob->dirname, message_id));
 255   goto RETURN;
 256   }
 257
 258 DEBUG(D_transport)
 259   debug_printf("%s transport succeeded\n", tblock->name);
 260
 261 addr->transport_return = OK;
 262
 263 RETURN:
 264 if (ddfd >= 0) (void) close(ddfd);
 265 if (sdfd >= 0) (void) close(sdfd);
 266
 267 /* A return of FALSE means that if there was an error, a common error was
 268 put in the first address of a batch. */
 269 return FALSE;
 270 }
 271
 272 #endif /*!MACRO_PREDEF*/