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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 12:06:34 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 12:06:34 +0000 |
commit | 5e61585d76ae77fd5e9e96ebabb57afa4d74880d (patch) | |
tree | 2b467823aaeebc7ef8bc9e3cabe8074eaef1666d /src/util/dict_cdb.c | |
parent | Initial commit. (diff) | |
download | postfix-upstream/3.5.24.tar.xz postfix-upstream/3.5.24.zip |
Adding upstream version 3.5.24.upstream/3.5.24upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/util/dict_cdb.c')
-rw-r--r-- | src/util/dict_cdb.c | 446 |
1 files changed, 446 insertions, 0 deletions
diff --git a/src/util/dict_cdb.c b/src/util/dict_cdb.c new file mode 100644 index 0000000..85e49a4 --- /dev/null +++ b/src/util/dict_cdb.c @@ -0,0 +1,446 @@ +/*++ +/* NAME +/* dict_cdb 3 +/* SUMMARY +/* dictionary manager interface to CDB files +/* SYNOPSIS +/* #include <dict_cdb.h> +/* +/* DICT *dict_cdb_open(path, open_flags, dict_flags) +/* const char *path; +/* int open_flags; +/* int dict_flags; +/* +/* DESCRIPTION +/* dict_cdb_open() opens the specified CDB database. The result is +/* a pointer to a structure that can be used to access the dictionary +/* using the generic methods documented in dict_open(3). +/* +/* Arguments: +/* .IP path +/* The database pathname, not including the ".cdb" suffix. +/* .IP open_flags +/* Flags passed to open(). Specify O_RDONLY or O_WRONLY|O_CREAT|O_TRUNC. +/* .IP dict_flags +/* Flags used by the dictionary interface. +/* SEE ALSO +/* dict(3) generic dictionary manager +/* DIAGNOSTICS +/* Fatal errors: cannot open file, write error, out of memory. +/* LICENSE +/* .ad +/* .fi +/* The Secure Mailer license must be distributed with this software. +/* AUTHOR(S) +/* Michael Tokarev <mjt@tls.msk.ru> based on dict_db.c by +/* Wietse Venema +/* IBM T.J. Watson Research +/* P.O. Box 704 +/* Yorktown Heights, NY 10598, USA +/*--*/ + +#include "sys_defs.h" + +/* System library. */ + +#include <sys/stat.h> +#include <limits.h> +#include <string.h> +#include <unistd.h> +#include <stdio.h> + +/* Utility library. */ + +#include "msg.h" +#include "mymalloc.h" +#include "vstring.h" +#include "stringops.h" +#include "iostuff.h" +#include "myflock.h" +#include "stringops.h" +#include "dict.h" +#include "dict_cdb.h" +#include "warn_stat.h" + +#ifdef HAS_CDB + +#include <cdb.h> +#ifndef TINYCDB_VERSION +#include <cdb_make.h> +#endif +#ifndef cdb_fileno +#define cdb_fileno(c) ((c)->fd) +#endif + +#ifndef CDB_SUFFIX +#define CDB_SUFFIX ".cdb" +#endif +#ifndef CDB_TMP_SUFFIX +#define CDB_TMP_SUFFIX CDB_SUFFIX ".tmp" +#endif + +/* Application-specific. */ + +typedef struct { + DICT dict; /* generic members */ + struct cdb cdb; /* cdb structure */ +} DICT_CDBQ; /* query interface */ + +typedef struct { + DICT dict; /* generic members */ + struct cdb_make cdbm; /* cdb_make structure */ + char *cdb_path; /* cdb pathname (.cdb) */ + char *tmp_path; /* temporary pathname (.tmp) */ +} DICT_CDBM; /* rebuild interface */ + +/* dict_cdbq_lookup - find database entry, query mode */ + +static const char *dict_cdbq_lookup(DICT *dict, const char *name) +{ + DICT_CDBQ *dict_cdbq = (DICT_CDBQ *) dict; + unsigned vlen; + int status = 0; + static char *buf; + static unsigned len; + const char *result = 0; + + dict->error = 0; + + /* CDB is constant, so do not try to acquire a lock. */ + + /* + * Optionally fold the key. + */ + if (dict->flags & DICT_FLAG_FOLD_FIX) { + if (dict->fold_buf == 0) + dict->fold_buf = vstring_alloc(10); + vstring_strcpy(dict->fold_buf, name); + name = lowercase(vstring_str(dict->fold_buf)); + } + + /* + * See if this CDB file was written with one null byte appended to key + * and value. + */ + if (dict->flags & DICT_FLAG_TRY1NULL) { + status = cdb_find(&dict_cdbq->cdb, name, strlen(name) + 1); + if (status > 0) + dict->flags &= ~DICT_FLAG_TRY0NULL; + } + + /* + * See if this CDB file was written with no null byte appended to key and + * value. + */ + if (status == 0 && (dict->flags & DICT_FLAG_TRY0NULL)) { + status = cdb_find(&dict_cdbq->cdb, name, strlen(name)); + if (status > 0) + dict->flags &= ~DICT_FLAG_TRY1NULL; + } + if (status < 0) + msg_fatal("error reading %s: %m", dict->name); + + if (status) { + vlen = cdb_datalen(&dict_cdbq->cdb); + if (len < vlen) { + if (buf == 0) + buf = mymalloc(vlen + 1); + else + buf = myrealloc(buf, vlen + 1); + len = vlen; + } + if (cdb_read(&dict_cdbq->cdb, buf, vlen, + cdb_datapos(&dict_cdbq->cdb)) < 0) + msg_fatal("error reading %s: %m", dict->name); + buf[vlen] = '\0'; + result = buf; + } + /* No locking so not release the lock. */ + + return (result); +} + +/* dict_cdbq_close - close data base, query mode */ + +static void dict_cdbq_close(DICT *dict) +{ + DICT_CDBQ *dict_cdbq = (DICT_CDBQ *) dict; + + cdb_free(&dict_cdbq->cdb); + close(dict->stat_fd); + if (dict->fold_buf) + vstring_free(dict->fold_buf); + dict_free(dict); +} + +/* dict_cdbq_open - open data base, query mode */ + +static DICT *dict_cdbq_open(const char *path, int dict_flags) +{ + DICT_CDBQ *dict_cdbq; + struct stat st; + char *cdb_path; + int fd; + + /* + * Let the optimizer worry about eliminating redundant code. + */ +#define DICT_CDBQ_OPEN_RETURN(d) do { \ + DICT *__d = (d); \ + myfree(cdb_path); \ + return (__d); \ + } while (0) + + cdb_path = concatenate(path, CDB_SUFFIX, (char *) 0); + + if ((fd = open(cdb_path, O_RDONLY)) < 0) + DICT_CDBQ_OPEN_RETURN(dict_surrogate(DICT_TYPE_CDB, path, + O_RDONLY, dict_flags, + "open database %s: %m", cdb_path)); + + dict_cdbq = (DICT_CDBQ *) dict_alloc(DICT_TYPE_CDB, + cdb_path, sizeof(*dict_cdbq)); +#if defined(TINYCDB_VERSION) + if (cdb_init(&(dict_cdbq->cdb), fd) != 0) + msg_fatal("dict_cdbq_open: unable to init %s: %m", cdb_path); +#else + cdb_init(&(dict_cdbq->cdb), fd); +#endif + dict_cdbq->dict.lookup = dict_cdbq_lookup; + dict_cdbq->dict.close = dict_cdbq_close; + dict_cdbq->dict.stat_fd = fd; + if (fstat(fd, &st) < 0) + msg_fatal("dict_dbq_open: fstat: %m"); + dict_cdbq->dict.mtime = st.st_mtime; + dict_cdbq->dict.owner.uid = st.st_uid; + dict_cdbq->dict.owner.status = (st.st_uid != 0); + close_on_exec(fd, CLOSE_ON_EXEC); + + /* + * Warn if the source file is newer than the indexed file, except when + * the source file changed only seconds ago. + */ + if (stat(path, &st) == 0 + && st.st_mtime > dict_cdbq->dict.mtime + && st.st_mtime < time((time_t *) 0) - 100) + msg_warn("database %s is older than source file %s", cdb_path, path); + + /* + * If undecided about appending a null byte to key and value, choose to + * try both in query mode. + */ + if ((dict_flags & (DICT_FLAG_TRY1NULL | DICT_FLAG_TRY0NULL)) == 0) + dict_flags |= DICT_FLAG_TRY0NULL | DICT_FLAG_TRY1NULL; + dict_cdbq->dict.flags = dict_flags | DICT_FLAG_FIXED; + if (dict_flags & DICT_FLAG_FOLD_FIX) + dict_cdbq->dict.fold_buf = vstring_alloc(10); + + DICT_CDBQ_OPEN_RETURN(DICT_DEBUG (&dict_cdbq->dict)); +} + +/* dict_cdbm_update - add database entry, create mode */ + +static int dict_cdbm_update(DICT *dict, const char *name, const char *value) +{ + DICT_CDBM *dict_cdbm = (DICT_CDBM *) dict; + unsigned ksize, vsize; + int r; + + dict->error = 0; + + /* + * Optionally fold the key. + */ + if (dict->flags & DICT_FLAG_FOLD_FIX) { + if (dict->fold_buf == 0) + dict->fold_buf = vstring_alloc(10); + vstring_strcpy(dict->fold_buf, name); + name = lowercase(vstring_str(dict->fold_buf)); + } + ksize = strlen(name); + vsize = strlen(value); + + /* + * Optionally append a null byte to key and value. + */ + if (dict->flags & DICT_FLAG_TRY1NULL) { + ksize++; + vsize++; + } + + /* + * Do the add operation. No locking is done. + */ +#ifdef TINYCDB_VERSION +#ifndef CDB_PUT_ADD +#error please upgrate tinycdb to at least 0.5 version +#endif + if (dict->flags & DICT_FLAG_DUP_IGNORE) + r = CDB_PUT_ADD; + else if (dict->flags & DICT_FLAG_DUP_REPLACE) + r = CDB_PUT_REPLACE; + else + r = CDB_PUT_INSERT; + r = cdb_make_put(&dict_cdbm->cdbm, name, ksize, value, vsize, r); + if (r < 0) + msg_fatal("error writing %s: %m", dict_cdbm->tmp_path); + else if (r > 0) { + if (dict->flags & (DICT_FLAG_DUP_IGNORE | DICT_FLAG_DUP_REPLACE)) + /* void */ ; + else if (dict->flags & DICT_FLAG_DUP_WARN) + msg_warn("%s: duplicate entry: \"%s\"", + dict_cdbm->dict.name, name); + else + msg_fatal("%s: duplicate entry: \"%s\"", + dict_cdbm->dict.name, name); + } + return (r); +#else + if (cdb_make_add(&dict_cdbm->cdbm, name, ksize, value, vsize) < 0) + msg_fatal("error writing %s: %m", dict_cdbm->tmp_path); + return (0); +#endif +} + +/* dict_cdbm_close - close data base and rename file.tmp to file.cdb */ + +static void dict_cdbm_close(DICT *dict) +{ + DICT_CDBM *dict_cdbm = (DICT_CDBM *) dict; + int fd = cdb_fileno(&dict_cdbm->cdbm); + + /* + * Note: if FCNTL locking is used, closing any file descriptor on a + * locked file cancels all locks that the process may have on that file. + * CDB is FCNTL locking safe, because it uses the same file descriptor + * for database I/O and locking. + */ + if (cdb_make_finish(&dict_cdbm->cdbm) < 0) + msg_fatal("finish database %s: %m", dict_cdbm->tmp_path); + if (rename(dict_cdbm->tmp_path, dict_cdbm->cdb_path) < 0) + msg_fatal("rename database from %s to %s: %m", + dict_cdbm->tmp_path, dict_cdbm->cdb_path); + if (close(fd) < 0) /* releases a lock */ + msg_fatal("close database %s: %m", dict_cdbm->cdb_path); + myfree(dict_cdbm->cdb_path); + myfree(dict_cdbm->tmp_path); + if (dict->fold_buf) + vstring_free(dict->fold_buf); + dict_free(dict); +} + +/* dict_cdbm_open - create database as file.tmp */ + +static DICT *dict_cdbm_open(const char *path, int dict_flags) +{ + DICT_CDBM *dict_cdbm; + char *cdb_path; + char *tmp_path; + int fd; + struct stat st0, st1; + + /* + * Let the optimizer worry about eliminating redundant code. + */ +#define DICT_CDBM_OPEN_RETURN(d) do { \ + DICT *__d = (d); \ + if (cdb_path) \ + myfree(cdb_path); \ + if (tmp_path) \ + myfree(tmp_path); \ + return (__d); \ + } while (0) + + cdb_path = concatenate(path, CDB_SUFFIX, (char *) 0); + tmp_path = concatenate(path, CDB_TMP_SUFFIX, (char *) 0); + + /* + * Repeat until we have opened *and* locked *existing* file. Since the + * new (tmp) file will be renamed to be .cdb file, locking here is + * somewhat funny to work around possible race conditions. Note that we + * can't open a file with O_TRUNC as we can't know if another process + * isn't creating it at the same time. + */ + for (;;) { + if ((fd = open(tmp_path, O_RDWR | O_CREAT, 0644)) < 0) + DICT_CDBM_OPEN_RETURN(dict_surrogate(DICT_TYPE_CDB, path, + O_RDWR, dict_flags, + "open database %s: %m", + tmp_path)); + if (fstat(fd, &st0) < 0) + msg_fatal("fstat(%s): %m", tmp_path); + + /* + * Get an exclusive lock - we're going to change the database so we + * can't have any spectators. + */ + if (myflock(fd, INTERNAL_LOCK, MYFLOCK_OP_EXCLUSIVE) < 0) + msg_fatal("lock %s: %m", tmp_path); + + if (stat(tmp_path, &st1) < 0) + msg_fatal("stat(%s): %m", tmp_path); + + /* + * Compare file's state before and after lock: should be the same, + * and nlinks should be >0, or else we opened non-existing file... + */ + if (st0.st_ino == st1.st_ino && st0.st_dev == st1.st_dev + && st0.st_rdev == st1.st_rdev && st0.st_nlink == st1.st_nlink + && st0.st_nlink > 0) + break; /* successefully opened */ + + close(fd); + + } + +#ifndef NO_FTRUNCATE + if (st0.st_size) + ftruncate(fd, 0); +#endif + + dict_cdbm = (DICT_CDBM *) dict_alloc(DICT_TYPE_CDB, path, + sizeof(*dict_cdbm)); + if (cdb_make_start(&dict_cdbm->cdbm, fd) < 0) + msg_fatal("initialize database %s: %m", tmp_path); + dict_cdbm->dict.close = dict_cdbm_close; + dict_cdbm->dict.update = dict_cdbm_update; + dict_cdbm->cdb_path = cdb_path; + dict_cdbm->tmp_path = tmp_path; + cdb_path = tmp_path = 0; /* DICT_CDBM_OPEN_RETURN() */ + dict_cdbm->dict.owner.uid = st1.st_uid; + dict_cdbm->dict.owner.status = (st1.st_uid != 0); + close_on_exec(fd, CLOSE_ON_EXEC); + + /* + * If undecided about appending a null byte to key and value, choose a + * default to not append a null byte when creating a cdb. + */ + if ((dict_flags & (DICT_FLAG_TRY1NULL | DICT_FLAG_TRY0NULL)) == 0) + dict_flags |= DICT_FLAG_TRY0NULL; + else if ((dict_flags & DICT_FLAG_TRY1NULL) + && (dict_flags & DICT_FLAG_TRY0NULL)) + dict_flags &= ~DICT_FLAG_TRY0NULL; + dict_cdbm->dict.flags = dict_flags | DICT_FLAG_FIXED; + if (dict_flags & DICT_FLAG_FOLD_FIX) + dict_cdbm->dict.fold_buf = vstring_alloc(10); + + DICT_CDBM_OPEN_RETURN(DICT_DEBUG (&dict_cdbm->dict)); +} + +/* dict_cdb_open - open data base for query mode or create mode */ + +DICT *dict_cdb_open(const char *path, int open_flags, int dict_flags) +{ + switch (open_flags & (O_RDONLY | O_RDWR | O_WRONLY | O_CREAT | O_TRUNC)) { + case O_RDONLY: /* query mode */ + return dict_cdbq_open(path, dict_flags); + case O_WRONLY | O_CREAT | O_TRUNC: /* create mode */ + case O_RDWR | O_CREAT | O_TRUNC: /* sloppiness */ + return dict_cdbm_open(path, dict_flags); + default: + msg_fatal("dict_cdb_open: inappropriate open flags for cdb database" + " - specify O_RDONLY or O_WRONLY|O_CREAT|O_TRUNC"); + } +} + +#endif /* HAS_CDB */ |