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Diffstat (limited to 'src/VREF/refex-expr')
| -rwxr-xr-x | src/VREF/refex-expr | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/src/VREF/refex-expr b/src/VREF/refex-expr new file mode 100755 index 0000000..b788dd9 --- /dev/null +++ b/src/VREF/refex-expr @@ -0,0 +1,99 @@ +#!/usr/bin/perl +use strict; +use warnings; + +# see bottom of this file for instructons and IMPORTANT WARNINGS! +# ---------------------------------------------------------------------- + +my $rule = $ARGV[7]; +die "\n\nFATAL: GL_REFEX_EXPR_ doesn't exist\n(your admin probably forgot the rc file change needed for this to work)\n\n" + unless exists $ENV{ "GL_REFEX_EXPR_" . $rule }; +my $res = $ENV{ "GL_REFEX_EXPR_" . $rule } || 0; +print "$ARGV[6] ($res)\n" if $res; + +exit 0; + +__END__ + +------------------------------------------------------------------------ +IMPORTANT WARNINGS: + * has not been tested heavily + * SO PLEASE TEST YOUR SPECIFIC USE CASE THOROUGHLY! + * read the NOTES section below + * syntax and semantics are to be considered beta and may change as I find + better use cases +------------------------------------------------------------------------ + +Refex expressions, like VREFs, are best used as additional "deny" rules, to +deny combinations that the normal ruleset cannot detect. + +To enable this, uncomment 'refex-expr' in the ENABLE list in the rc file. + +It allows you to say things like "don't allow users u3 and u4 to change the +Makefile in the master branch" (i.e., they can change any other file in +master, or the Makefile in any other branch, but not that specific combo). + + repo foo + RW+ = u1 u2 # line 1 + + RW+ master = u3 u4 # line 2 + RW+ = u3 u4 # line 3 + RW+ VREF/NAME/Makefile = u3 u4 # line 4 + - master and VREF/NAME/Makefile = u3 u4 # line 5 + +Line 5 is a "refex expression". Here are the rules: + + * for each refex in the expression ("master" and "VREF/NAME/Makefile" in + this example), a count is kept of the number of times the EXACT refex was + matched and allowed in the *normal* rules (here, lines 2 and 4) during + this push. + + * the expression is evaluated based on these counts. 0 is false, and + any non-zero is true (see more examples later). The truth value of the + expression determines whether the refex expression matched. + + You can use any logical or arithmetic expression using refexes as operands + and using these operators: + + not and or xor + - == -lt -gt -eq -le -ge -ne + + Parens are not allowed. Precedence is as you might expect for those + operators. It's actually perl that is evaluating it (you can guess what + the '-lt' etc., get translated to) so if in doubt, check 'man perlop'. + + * the refexes that form the terms of the expression (in this case, lines 2 + and 4) MUST come before the expression itself (i.e., line 5). + + * note the words "EXACT refex was matched" above. + + Let's say you add "u3" to line 1. Then the refex expression in line 5 + would never match for u3. This is because line 1 prevents line 2 from + matching (being more general *and* appearing earlier), so the count for + the "master" refex would be 0. If "master" is 0 (false), then "master and + <anything>" is also false. + + (Same thing is you swap lines 2 and 3; i.e., put the "RW+ = ..." before + the "RW+ master = ..."). + + Put another way, the terms in the refex expression are refexes, not refs. + Merely pushing the master branch does not mean the count for "master" + increases; it has to *match* on a line that has "master" as the refex. + +Here are some more examples: + + * user u2 is allowed to push either 'doc/' or 'src/' but not both + + repo foo + RW+ = u1 u2 u3 + + RW+ VREF/NAME/doc/ = u2 + RW+ VREF/NAME/src/ = u2 + - VREF/NAME/doc/ and VREF/NAME/src/ = u2 + + * user u3 is allowed to push at most 2 files to conf/ + + repo foo + RW+ = u1 u2 u3 + + RW+ VREF/NAME/conf/ = u3 + - VREF/NAME/conf/ -gt 2 = u3 |