diff options
Diffstat (limited to 'src/transports/queuefile.c')
| -rw-r--r-- | src/transports/queuefile.c | 286 |
1 files changed, 286 insertions, 0 deletions
diff --git a/src/transports/queuefile.c b/src/transports/queuefile.c new file mode 100644 index 0000000..74131cc --- /dev/null +++ b/src/transports/queuefile.c @@ -0,0 +1,286 @@ +/************************************************* +* Exim - an Internet mail transport agent * +*************************************************/ + +/* Copyright (c) Andrew Colin Kissa <andrew@topdog.za.net> 2016 */ +/* Copyright (c) University of Cambridge 2016 */ +/* Copyright (c) The Exim Maintainers 1995 - 2021 */ +/* See the file NOTICE for conditions of use and distribution. */ + + + +#include "../exim.h" + +#ifdef EXPERIMENTAL_QUEUEFILE /* whole file */ +#include "queuefile.h" + +#ifndef EXIM_HAVE_OPENAT +# error queuefile transport reqires openat() support +#endif + +/* Options specific to the appendfile transport. They must be in alphabetic +order (note that "_" comes before the lower case letters). Some of them are +stored in the publicly visible instance block - these are flagged with the +opt_public flag. */ + +optionlist queuefile_transport_options[] = { + { "directory", opt_stringptr, + OPT_OFF(queuefile_transport_options_block, dirname) }, +}; + + +/* Size of the options list. An extern variable has to be used so that its +address can appear in the tables drtables.c. */ + +int queuefile_transport_options_count = + sizeof(queuefile_transport_options) / sizeof(optionlist); + + +#ifdef MACRO_PREDEF + +/* Dummy values */ +queuefile_transport_options_block queuefile_transport_option_defaults = {0}; +void queuefile_transport_init(transport_instance *tblock) {} +BOOL queuefile_transport_entry(transport_instance *tblock, address_item *addr) {return FALSE;} + +#else /*!MACRO_PREDEF*/ + + + +/* Default private options block for the appendfile transport. */ + +queuefile_transport_options_block queuefile_transport_option_defaults = { + NULL, /* dirname */ +}; + +/************************************************* +* Initialization entry point * +*************************************************/ + +void queuefile_transport_init(transport_instance *tblock) +{ +queuefile_transport_options_block *ob = + (queuefile_transport_options_block *) tblock->options_block; + +if (!ob->dirname) + log_write(0, LOG_PANIC_DIE | LOG_CONFIG, + "directory must be set for the %s transport", tblock->name); +} + +/* This function will copy from a file to another + +Arguments: + dst fd to write to (the destination queue file) + src fd to read from (the spool queue file) + +Returns: TRUE if all went well, FALSE otherwise with errno set +*/ + +static BOOL +copy_spool_file(int dst, int src) +{ +int i, j; +uschar buffer[16384]; + +if (lseek(src, 0, SEEK_SET) != 0) + return FALSE; + +do + if ((j = read(src, buffer, sizeof(buffer))) > 0) + for (uschar * s = buffer; (i = write(dst, s, j)) != j; s += i, j -= i) + if (i < 0) + return FALSE; + else if (j < 0) + return FALSE; +while (j > 0); +return TRUE; +} + +/* This function performs the actual copying of the header +and data files to the destination directory + +Arguments: + tb the transport block + addr address_item being processed + dstpath destination directory name + sdfd int Source directory fd + ddfd int Destination directory fd + link_file BOOL use linkat instead of data copy + srcfd fd for data file, or -1 for header file + +Returns: TRUE if all went well, FALSE otherwise +*/ + +static BOOL +copy_spool_files(transport_instance * tb, address_item * addr, + const uschar * dstpath, int sdfd, int ddfd, BOOL link_file, int srcfd) +{ +BOOL is_hdr_file = srcfd < 0; +const uschar * suffix = srcfd < 0 ? US"H" : US"D"; +int dstfd; +const uschar * filename = string_sprintf("%s-%s", message_id, suffix); +const uschar * srcpath = spool_fname(US"input", message_subdir, message_id, suffix); +const uschar * s, * op; + +dstpath = string_sprintf("%s/%s-%s", dstpath, message_id, suffix); + +if (link_file) + { + DEBUG(D_transport) debug_printf("%s transport, linking %s => %s\n", + tb->name, srcpath, dstpath); + + if (linkat(sdfd, CCS filename, ddfd, CCS filename, 0) >= 0) + return TRUE; + + op = US"linking"; + s = dstpath; + } +else /* use data copy */ + { + DEBUG(D_transport) debug_printf("%s transport, copying %s => %s\n", + tb->name, srcpath, dstpath); + + if ( (s = dstpath, + (dstfd = exim_openat4(ddfd, CCS filename, O_RDWR|O_CREAT|O_EXCL, SPOOL_MODE)) + < 0 + ) + || is_hdr_file + && (s = srcpath, (srcfd = exim_openat(sdfd, CCS filename, O_RDONLY)) < 0) + ) + op = US"opening"; + + else + if (s = dstpath, fchmod(dstfd, SPOOL_MODE) != 0) + op = US"setting perms on"; + else + if (!copy_spool_file(dstfd, srcfd)) + op = US"creating"; + else + return TRUE; + } + +addr->basic_errno = errno; +addr->message = string_sprintf("%s transport %s file: %s failed with error: %s", + tb->name, op, s, strerror(errno)); +addr->transport_return = DEFER; +return FALSE; +} + +/************************************************* +* Main entry point * +*************************************************/ + +/* This transport always returns FALSE, indicating that the status in +the first address is the status for all addresses in a batch. */ + +BOOL +queuefile_transport_entry(transport_instance * tblock, address_item * addr) +{ +queuefile_transport_options_block * ob = + (queuefile_transport_options_block *) tblock->options_block; +BOOL can_link; +uschar * sourcedir = spool_dname(US"input", message_subdir); +uschar * s, * dstdir; +struct stat dstatbuf, sstatbuf; +int ddfd = -1, sdfd = -1; + +DEBUG(D_transport) + debug_printf("%s transport entered\n", tblock->name); + +#ifndef O_DIRECTORY +# define O_DIRECTORY 0 +#endif +#ifndef O_NOFOLLOW +# define O_NOFOLLOW 0 +#endif + +if (!(dstdir = expand_string(ob->dirname))) + { + addr->message = string_sprintf("%s transport: failed to expand dirname option", + tblock->name); + addr->transport_return = DEFER; + return FALSE; + } +if (*dstdir != '/') + { + addr->transport_return = PANIC; + addr->message = string_sprintf("%s transport directory: " + "%s is not absolute", tblock->name, dstdir); + return FALSE; + } + +/* Open the source and destination directories and check if they are +on the same filesystem, so we can hard-link files rather than copying. */ + +if ( (s = dstdir, + (ddfd = Uopen(s, O_RDONLY | O_DIRECTORY | O_NOFOLLOW, 0)) < 0) + || (s = sourcedir, + (sdfd = Uopen(sourcedir, O_RDONLY | O_DIRECTORY | O_NOFOLLOW, 0)) < 0) + ) + { + addr->transport_return = PANIC; + addr->basic_errno = errno; + addr->message = string_sprintf("%s transport accessing directory: %s " + "failed with error: %s", tblock->name, s, strerror(errno)); + if (ddfd >= 0) (void) close(ddfd); + return FALSE; + } + +if ( (s = dstdir, fstat(ddfd, &dstatbuf) < 0) + || (s = sourcedir, fstat(sdfd, &sstatbuf) < 0) + ) + { + addr->transport_return = PANIC; + addr->basic_errno = errno; + addr->message = string_sprintf("%s transport fstat on directory fd: " + "%s failed with error: %s", tblock->name, s, strerror(errno)); + goto RETURN; + } +can_link = (dstatbuf.st_dev == sstatbuf.st_dev); + +if (f.dont_deliver) + { + DEBUG(D_transport) + debug_printf("*** delivery by %s transport bypassed by -N option\n", + tblock->name); + addr->transport_return = OK; + goto RETURN; + } + +/* Link or copy the header and data spool files */ + +DEBUG(D_transport) + debug_printf("%s transport, copying header file\n", tblock->name); + +if (!copy_spool_files(tblock, addr, dstdir, sdfd, ddfd, can_link, -1)) + goto RETURN; + +DEBUG(D_transport) + debug_printf("%s transport, copying data file\n", tblock->name); + +if (!copy_spool_files(tblock, addr, dstdir, sdfd, ddfd, can_link, + deliver_datafile)) + { + DEBUG(D_transport) + debug_printf("%s transport, copying data file failed, " + "unlinking the header file\n", tblock->name); + Uunlink(string_sprintf("%s/%s-H", dstdir, message_id)); + goto RETURN; + } + +DEBUG(D_transport) + debug_printf("%s transport succeeded\n", tblock->name); + +addr->transport_return = OK; + +RETURN: +if (ddfd >= 0) (void) close(ddfd); +if (sdfd >= 0) (void) close(sdfd); + +/* A return of FALSE means that if there was an error, a common error was +put in the first address of a batch. */ +return FALSE; +} + +#endif /*!MACRO_PREDEF*/ +#endif /*EXPERIMENTAL_QUEUEFILE*/ |