diff options
Diffstat (limited to 'src/fluent-bit/plugins/in_tail/tail_scan_glob.c')
| -rw-r--r-- | src/fluent-bit/plugins/in_tail/tail_scan_glob.c | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/src/fluent-bit/plugins/in_tail/tail_scan_glob.c b/src/fluent-bit/plugins/in_tail/tail_scan_glob.c new file mode 100644 index 000000000..b330b7c3b --- /dev/null +++ b/src/fluent-bit/plugins/in_tail/tail_scan_glob.c @@ -0,0 +1,278 @@ +/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ + +/* Fluent Bit + * ========== + * Copyright (C) 2015-2022 The Fluent Bit Authors + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include <sys/types.h> +#include <sys/stat.h> +#include <glob.h> +#include <fnmatch.h> + +#include <fluent-bit/flb_compat.h> +#include <fluent-bit/flb_input_plugin.h> +#include <fluent-bit/flb_utils.h> + +#include "tail.h" +#include "tail_file.h" +#include "tail_signal.h" +#include "tail_scan.h" +#include "tail_config.h" + +/* Define missing GLOB_TILDE if not exists */ +#ifndef GLOB_TILDE +#define GLOB_TILDE 1<<2 /* use GNU Libc value */ +#define UNSUP_TILDE 1 + +/* we need these extra headers for path resolution */ +#include <limits.h> +#include <sys/types.h> +#include <pwd.h> + +static char *expand_tilde(const char *path) +{ + int len; + char user[256]; + char *p = NULL; + char *dir = NULL; + char *tmp = NULL; + struct passwd *uinfo = NULL; + + if (path[0] == '~') { + p = strchr(path, '/'); + + if (p) { + /* check case '~/' */ + if ((p - path) == 1) { + dir = getenv("HOME"); + if (!dir) { + return path; + } + } + else { + /* + * it refers to a different user: ~user/abc, first step grab + * the user name. + */ + len = (p - path) - 1; + memcpy(user, path + 1, len); + user[len] = '\0'; + + /* use getpwnam() to resolve user information */ + uinfo = getpwnam(user); + if (!uinfo) { + return path; + } + + dir = uinfo->pw_dir; + } + } + else { + dir = getenv("HOME"); + if (!dir) { + return path; + } + } + + if (p) { + tmp = flb_malloc(PATH_MAX); + if (!tmp) { + flb_errno(); + return NULL; + } + snprintf(tmp, PATH_MAX - 1, "%s%s", dir, p); + } + else { + dir = getenv("HOME"); + if (!dir) { + return path; + } + + tmp = flb_strdup(dir); + if (!tmp) { + return path; + } + } + + return tmp; + } + + return path; +} +#endif + +static int tail_is_excluded(char *path, struct flb_tail_config *ctx) +{ + struct mk_list *head; + struct flb_slist_entry *pattern; + + if (!ctx->exclude_list) { + return FLB_FALSE; + } + + mk_list_foreach(head, ctx->exclude_list) { + pattern = mk_list_entry(head, struct flb_slist_entry, _head); + if (fnmatch(pattern->str, path, 0) == 0) { + return FLB_TRUE; + } + } + + return FLB_FALSE; +} + +static inline int do_glob(const char *pattern, int flags, + void *not_used, glob_t *pglob) +{ + int ret; + int new_flags; + char *tmp = NULL; + int tmp_needs_free = FLB_FALSE; + (void) not_used; + + /* Save current values */ + new_flags = flags; + + if (flags & GLOB_TILDE) { +#ifdef UNSUP_TILDE + /* + * Some libc libraries like Musl do not support GLOB_TILDE for tilde + * expansion. A workaround is to use wordexp(3) but looking at it + * implementation in Musl it looks quite expensive: + * + * http://git.musl-libc.org/cgit/musl/tree/src/misc/wordexp.c + * + * the workaround is to do our own tilde expansion in a temporary buffer. + */ + + /* Look for a tilde */ + tmp = expand_tilde(pattern); + if (tmp != pattern) { + /* the path was expanded */ + pattern = tmp; + tmp_needs_free = FLB_TRUE; + } + + /* remove unused flag */ + new_flags &= ~GLOB_TILDE; +#endif + } + + /* invoke glob with new parameters */ + ret = glob(pattern, new_flags, NULL, pglob); + + /* remove temporary buffer, if allocated by expand_tilde above. + * Note that this buffer is only used for libc implementations + * that do not support the GLOB_TILDE flag, like musl. */ + if ((tmp != NULL) && (tmp_needs_free == FLB_TRUE)) { + flb_free(tmp); + } + + return ret; +} + +/* Scan a path, register the entries and return how many */ +static int tail_scan_path(const char *path, struct flb_tail_config *ctx) +{ + int i; + int ret; + int count = 0; + glob_t globbuf; + time_t now; + int64_t mtime; + struct stat st; + + flb_plg_debug(ctx->ins, "scanning path %s", path); + + /* Safe reset for globfree() */ + globbuf.gl_pathv = NULL; + + /* Scan the given path */ + ret = do_glob(path, GLOB_TILDE | GLOB_ERR, NULL, &globbuf); + if (ret != 0) { + switch (ret) { + case GLOB_NOSPACE: + flb_plg_error(ctx->ins, "no memory space available"); + return -1; + case GLOB_ABORTED: + flb_plg_error(ctx->ins, "read error, check permissions: %s", path); + return -1; + case GLOB_NOMATCH: + ret = stat(path, &st); + if (ret == -1) { + flb_plg_debug(ctx->ins, "cannot read info from: %s", path); + } + else { + ret = access(path, R_OK); + if (ret == -1 && errno == EACCES) { + flb_plg_error(ctx->ins, "NO read access for path: %s", path); + } + else { + flb_plg_debug(ctx->ins, "NO matches for path: %s", path); + } + } + return 0; + } + } + + + /* For every entry found, generate an output list */ + now = time(NULL); + for (i = 0; i < globbuf.gl_pathc; i++) { + ret = stat(globbuf.gl_pathv[i], &st); + if (ret == 0 && S_ISREG(st.st_mode)) { + /* Check if this file is blacklisted */ + if (tail_is_excluded(globbuf.gl_pathv[i], ctx) == FLB_TRUE) { + flb_plg_debug(ctx->ins, "excluded=%s", globbuf.gl_pathv[i]); + continue; + } + + if (ctx->ignore_older > 0) { + mtime = flb_tail_stat_mtime(&st); + if (mtime > 0) { + if ((now - ctx->ignore_older) > mtime) { + flb_plg_debug(ctx->ins, "excluded=%s (ignore_older)", + globbuf.gl_pathv[i]); + continue; + } + } + } + + /* Append file to list */ + ret = flb_tail_file_append(globbuf.gl_pathv[i], &st, + FLB_TAIL_STATIC, ctx); + if (ret == 0) { + flb_plg_debug(ctx->ins, "scan_glob add(): %s, inode %li", + globbuf.gl_pathv[i], st.st_ino); + count++; + } + else { + flb_plg_debug(ctx->ins, "scan_blog add(): dismissed: %s, inode %li", + globbuf.gl_pathv[i], st.st_ino); + } + } + else { + flb_plg_debug(ctx->ins, "skip (invalid) entry=%s", + globbuf.gl_pathv[i]); + } + } + + if (count > 0) { + tail_signal_manager(ctx); + } + + globfree(&globbuf); + return count; +} |