From fe3b1a2d21fb35ac212066dd74b7cc4b6bfbccc9 Mon Sep 17 00:00:00 2001 From: Sean Anderson Date: Tue, 27 Oct 2020 19:55:26 -0400 Subject: [PATCH] log: Add filter flag to deny on match Without this flag, log filters can only explicitly accept messages. Allowing denial makes it easier to filter certain subsystems. Unlike allow-ing filters, deny-ing filters are added to the beginning of the filter list. This should do the Right Thing most of the time, but it's less-universal than allowing filters to be inserted anywhere. If this becomes a problem, then perhaps log_filter_add* should take a filter number to insert before/after. Signed-off-by: Sean Anderson Reviewed-by: Simon Glass --- common/log.c | 12 ++++++++++-- include/log.h | 11 ++++++++++- 2 files changed, 20 insertions(+), 3 deletions(-) diff --git a/common/log.c b/common/log.c index b7b144fa5d..c1b6b6105f 100644 --- a/common/log.c +++ b/common/log.c @@ -170,7 +170,11 @@ static bool log_passes_filters(struct log_device *ldev, struct log_rec *rec) if (filt->file_list && !log_has_file(filt->file_list, rec->file)) continue; - return true; + + if (filt->flags & LOGFF_DENY) + return false; + else + return true; } return false; @@ -284,7 +288,11 @@ int log_add_filter_flags(const char *drv_name, enum log_category_t cat_list[], } } filt->filter_num = ldev->next_filter_num++; - list_add_tail(&filt->sibling_node, &ldev->filter_head); + /* Add deny filters to the beginning of the list */ + if (flags & LOGFF_DENY) + list_add(&filt->sibling_node, &ldev->filter_head); + else + list_add_tail(&filt->sibling_node, &ldev->filter_head); return filt->filter_num; diff --git a/include/log.h b/include/log.h index ee94f14ff0..05833f24bc 100644 --- a/include/log.h +++ b/include/log.h @@ -361,13 +361,22 @@ enum { LOGF_MAX_CATEGORIES = 5, /* maximum categories per filter */ }; +/** + * enum log_filter_flags - Flags which modify a filter + */ enum log_filter_flags { - LOGFF_HAS_CAT = 1 << 0, /* Filter has a category list */ + /** @LOGFF_HAS_CAT: Filter has a category list */ + LOGFF_HAS_CAT = 1 << 0, + /** @LOGFF_DENY: Filter denies matching messages */ + LOGFF_DENY = 1 << 1, }; /** * struct log_filter - criterial to filter out log messages * + * If a message matches all criteria, then it is allowed. If LOGFF_DENY is set, + * then it is denied instead. + * * @filter_num: Sequence number of this filter. This is returned when adding a * new filter, and must be provided when removing a previously added * filter. -- 2.39.5