From 8bca213b081ab4e2610d74b3e46306338b2a6809 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Tue, 28 Nov 2023 23:41:50 -0800 Subject: [PROPOSED] * localtime.c: Add size commentary. --- localtime.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/localtime.c b/localtime.c index 319fd4ee..1aee054f 100644 --- a/localtime.c +++ b/localtime.c @@ -112,6 +112,11 @@ enum { CHARS_EXTRA = max(sizeof UNSPEC, 2) - 1 }; # define TZNAME_MAXIMUM 255 #endif +/* A representation of the contents of a TZif file. Ideally this + would have no size limits; the following sizes should suffice for + practical use. This struct should not be too large, as instances + are put on the stack and stacks are relatively small on some platforms. + See tzfile.h for more about the sizes. */ struct state { int leapcnt; int timecnt; @@ -369,7 +374,8 @@ union input_buffer { /* The first part of the buffer, interpreted as a header. */ struct tzhead tzhead; - /* The entire buffer. */ + /* The entire buffer. Ideally this would have no size limits; + the following should suffice for practical use. */ char buf[2 * sizeof(struct tzhead) + 2 * sizeof(struct state) + 4 * TZ_MAX_TIMES]; }; @@ -388,7 +394,12 @@ union local_storage { struct state st; } u; - /* The file name to be opened. */ + /* The name of the file to be opened. Ideally this would have no + size limits, to support arbitrarily long Zone names. + Limiting Zone names to 1024 bytes should suffice for practical use. + However, there is no need for this to be smaller than struct + file_analysis as that struct is allocated anyway, as the other + union member. */ char fullname[max(sizeof(struct file_analysis), sizeof tzdirslash + 1024)]; }; -- 2.40.1