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Diffstat (limited to 'src/lookups/dbmdb.c')
-rw-r--r-- | src/lookups/dbmdb.c | 291 |
1 files changed, 291 insertions, 0 deletions
diff --git a/src/lookups/dbmdb.c b/src/lookups/dbmdb.c new file mode 100644 index 0000000..98ce74f --- /dev/null +++ b/src/lookups/dbmdb.c @@ -0,0 +1,291 @@ +/************************************************* +* Exim - an Internet mail transport agent * +*************************************************/ + +/* Copyright (c) University of Cambridge 1995 - 2018 */ +/* Copyright (c) The Exim Maintainers 2020 */ +/* See the file NOTICE for conditions of use and distribution. */ + +#include "../exim.h" +#include "lf_functions.h" + + +/************************************************* +* Open entry point * +*************************************************/ + +/* See local README for interface description */ + +static void * +dbmdb_open(const uschar * filename, uschar ** errmsg) +{ +uschar * dirname = string_copy(filename); +uschar * s; +EXIM_DB *yield = NULL; + +if ((s = Ustrrchr(dirname, '/'))) *s = '\0'; +EXIM_DBOPEN(filename, dirname, O_RDONLY, 0, &yield); +if (!yield) + { + int save_errno = errno; + *errmsg = string_open_failed(errno, "%s as a %s file", filename, EXIM_DBTYPE); + errno = save_errno; + } +return yield; +} + + + +/************************************************* +* Check entry point * +*************************************************/ + +/* This needs to know more about the underlying files than is good for it! +We need to know what the real file names are in order to check the owners and +modes. If USE_DB is set, we know it is Berkeley DB, which uses an unmodified +file name. If USE_TDB or USE_GDBM is set, we know it is tdb or gdbm, which do +the same. Otherwise, for safety, we have to check for x.db or x.dir and x.pag. +*/ + +static BOOL +dbmdb_check(void *handle, const uschar *filename, int modemask, uid_t *owners, + gid_t *owngroups, uschar **errmsg) +{ +int rc; +handle = handle; /* Keep picky compilers happy */ + +#if defined(USE_DB) || defined(USE_TDB) || defined(USE_GDBM) +rc = lf_check_file(-1, filename, S_IFREG, modemask, owners, owngroups, + "dbm", errmsg); +#else + { + uschar filebuffer[256]; + (void)sprintf(CS filebuffer, "%.250s.db", filename); + rc = lf_check_file(-1, filebuffer, S_IFREG, modemask, owners, owngroups, + "dbm", errmsg); + if (rc < 0) /* stat() failed */ + { + (void)sprintf(CS filebuffer, "%.250s.dir", filename); + rc = lf_check_file(-1, filebuffer, S_IFREG, modemask, owners, owngroups, + "dbm", errmsg); + if (rc == 0) /* x.dir was OK */ + { + (void)sprintf(CS filebuffer, "%.250s.pag", filename); + rc = lf_check_file(-1, filebuffer, S_IFREG, modemask, owners, owngroups, + "dbm", errmsg); + } + } + } +#endif + +return rc == 0; +} + + + +/************************************************* +* Find entry point * +*************************************************/ + +/* See local README for interface description. This function adds 1 to +the keylength in order to include the terminating zero. */ + +static int +dbmdb_find(void * handle, const uschar * filename, const uschar * keystring, + int length, uschar ** result, uschar ** errmsg, uint * do_cache, + const uschar * opts) +{ +EXIM_DB *d = (EXIM_DB *)handle; +EXIM_DATUM key, data; + +filename = filename; /* Keep picky compilers happy */ +errmsg = errmsg; +do_cache = do_cache; + +EXIM_DATUM_INIT(key); /* Some DBM libraries require datums to */ +EXIM_DATUM_INIT(data); /* be cleared before use. */ +EXIM_DATUM_DATA(key) = CS keystring; +EXIM_DATUM_SIZE(key) = length + 1; + +if (EXIM_DBGET(d, key, data)) + { + *result = string_copyn(US EXIM_DATUM_DATA(data), EXIM_DATUM_SIZE(data)); + EXIM_DATUM_FREE(data); /* Some DBM libraries need a free() call */ + return OK; + } +return FAIL; +} + + + +/************************************************* +* Find entry point - no zero on key * +*************************************************/ + +/* See local README for interface description */ + +static int +dbmnz_find(void * handle, const uschar * filename, const uschar * keystring, + int length, uschar ** result, uschar ** errmsg, uint * do_cache, + const uschar * opts) +{ +return dbmdb_find(handle, filename, keystring, length-1, result, errmsg, + do_cache, opts); +} + + + +/************************************************* +* Find entry point - zero-joined list key * +*************************************************/ + +/* + * The parameter passed as a key is a list in normal Exim list syntax. + * The elements of that list are joined together on NUL, with no trailing + * NUL, to form the key. + */ + +static int +dbmjz_find(void * handle, const uschar * filename, const uschar * keystring, + int length, uschar ** result, uschar ** errmsg, uint * do_cache, + const uschar * opts) +{ +uschar *key_item, *key_buffer, *key_p; +const uschar *key_elems = keystring; +int buflen, bufleft, key_item_len, sep = 0; + +/* To a first approximation, the size of the lookup key needs to be about, +or less than, the length of the delimited list passed in + 1. */ + +buflen = length + 3; +key_buffer = store_get(buflen, is_tainted(keystring)); + +key_buffer[0] = '\0'; + +key_p = key_buffer; +bufleft = buflen; + +/* In all cases of an empty list item, we can set 1 and advance by 1 and then +pick up the trailing NUL from the previous list item, EXCEPT when at the +beginning of the output string, in which case we need to supply that NUL +ourselves. */ +while ((key_item = string_nextinlist(&key_elems, &sep, key_p, bufleft)) != NULL) + { + key_item_len = Ustrlen(key_item) + 1; + if (key_item_len == 1) + { + key_p[0] = '\0'; + if (key_p == key_buffer) + { + key_p[1] = '\0'; + key_item_len += 1; + } + } + + bufleft -= key_item_len; + if (bufleft <= 0) + { + /* The string_nextinlist() will stop at buffer size, but we should always + have at least 1 character extra, so some assumption has failed. */ + *errmsg = string_copy(US"Ran out of buffer space for joining elements"); + return DEFER; + } + key_p += key_item_len; + } + +if (key_p == key_buffer) + { + *errmsg = string_copy(US"empty list key"); + return FAIL; + } + +/* We do not pass in the final NULL; if needed, the list should include an +empty element to put one in. Boundary: key length 1, is a NULL */ +key_item_len = key_p - key_buffer - 1; + +DEBUG(D_lookup) debug_printf_indent("NUL-joined key length: %d\n", key_item_len); + +/* beware that dbmdb_find() adds 1 to length to get back terminating NUL, so +because we've calculated the real length, we need to subtract one more here */ + +return dbmdb_find(handle, filename, key_buffer, key_item_len - 1, + result, errmsg, do_cache, opts); +} + + + +/************************************************* +* Close entry point * +*************************************************/ + +/* See local README for interface description */ + +void +static dbmdb_close(void *handle) +{ +EXIM_DBCLOSE((EXIM_DB *)handle); +} + + + +/************************************************* +* Version reporting entry point * +*************************************************/ + +/* See local README for interface description. */ + +#include "../version.h" + +void +dbm_version_report(FILE *f) +{ +#ifdef DYNLOOKUP +fprintf(f, "Library version: DBM: Exim version %s\n", EXIM_VERSION_STR); +#endif +} + + +lookup_info dbm_lookup_info = { + .name = US"dbm", /* lookup name */ + .type = lookup_absfile, /* uses absolute file name */ + .open = dbmdb_open, /* open function */ + .check = dbmdb_check, /* check function */ + .find = dbmdb_find, /* find function */ + .close = dbmdb_close, /* close function */ + .tidy = NULL, /* no tidy function */ + .quote = NULL, /* no quoting function */ + .version_report = dbm_version_report /* version reporting */ +}; + +lookup_info dbmz_lookup_info = { + .name = US"dbmnz", /* lookup name */ + .type = lookup_absfile, /* uses absolute file name */ + .open = dbmdb_open, /* sic */ /* open function */ + .check = dbmdb_check, /* sic */ /* check function */ + .find = dbmnz_find, /* find function */ + .close = dbmdb_close, /* sic */ /* close function */ + .tidy = NULL, /* no tidy function */ + .quote = NULL, /* no quoting function */ + .version_report = NULL /* no version reporting (redundant) */ +}; + +lookup_info dbmjz_lookup_info = { + .name = US"dbmjz", /* lookup name */ + .type = lookup_absfile, /* uses absolute file name */ + .open = dbmdb_open, /* sic */ /* open function */ + .check = dbmdb_check, /* sic */ /* check function */ + .find = dbmjz_find, /* find function */ + .close = dbmdb_close, /* sic */ /* close function */ + .tidy = NULL, /* no tidy function */ + .quote = NULL, /* no quoting function */ + .version_report = NULL /* no version reporting (redundant) */ +}; + +#ifdef DYNLOOKUP +#define dbmdb_lookup_module_info _lookup_module_info +#endif + +static lookup_info *_lookup_list[] = { &dbm_lookup_info, &dbmz_lookup_info, &dbmjz_lookup_info }; +lookup_module_info dbmdb_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 3 }; + +/* End of lookups/dbmdb.c */ |