glibc/RHEL-18039-1.patch
Florian Weimer 03bf7e6cdf Stub resolver configuration updates (RHEL-18039)
- Support clearing options in /etc/resolv.conf, RES_OPTIONS with a - prefix
- Introduce the strict-error/RES_STRICTERR stub resolver option
2024-07-26 14:00:09 +02:00

80 lines
3.4 KiB
Diff

commit 95f61610f3e481d191b6184432342236fd59186d
Author: Florian Weimer <fweimer@redhat.com>
Date: Wed Jul 24 12:06:47 2024 +0200
resolv: Support clearing option flags with a “-” prefix (bug 14799)
I think using a “-” prefix is less confusing than introducing
double-negation construct (“no-no-tld-query”).
Reviewed-by: DJ Delorie <dj@redhat.com>
diff --git a/resolv/res_init.c b/resolv/res_init.c
index 263263d474721545..243532b3ade338d8 100644
--- a/resolv/res_init.c
+++ b/resolv/res_init.c
@@ -682,27 +682,29 @@ res_setoptions (struct resolv_conf_parser *parser, const char *options)
{
char str[22];
uint8_t len;
- uint8_t clear;
unsigned long int flag;
} options[] = {
#define STRnLEN(str) str, sizeof (str) - 1
- { STRnLEN ("rotate"), 0, RES_ROTATE },
- { STRnLEN ("edns0"), 0, RES_USE_EDNS0 },
- { STRnLEN ("single-request-reopen"), 0, RES_SNGLKUPREOP },
- { STRnLEN ("single-request"), 0, RES_SNGLKUP },
- { STRnLEN ("no_tld_query"), 0, RES_NOTLDQUERY },
- { STRnLEN ("no-tld-query"), 0, RES_NOTLDQUERY },
- { STRnLEN ("no-reload"), 0, RES_NORELOAD },
- { STRnLEN ("use-vc"), 0, RES_USEVC },
- { STRnLEN ("trust-ad"), 0, RES_TRUSTAD },
- { STRnLEN ("no-aaaa"), 0, RES_NOAAAA },
+ { STRnLEN ("rotate"), RES_ROTATE },
+ { STRnLEN ("edns0"), RES_USE_EDNS0 },
+ { STRnLEN ("single-request-reopen"), RES_SNGLKUPREOP },
+ { STRnLEN ("single-request"), RES_SNGLKUP },
+ { STRnLEN ("no_tld_query"), RES_NOTLDQUERY },
+ { STRnLEN ("no-tld-query"), RES_NOTLDQUERY },
+ { STRnLEN ("no-reload"), RES_NORELOAD },
+ { STRnLEN ("use-vc"), RES_USEVC },
+ { STRnLEN ("trust-ad"), RES_TRUSTAD },
+ { STRnLEN ("no-aaaa"), RES_NOAAAA },
};
#define noptions (sizeof (options) / sizeof (options[0]))
+ bool negate_option = *cp == '-';
+ if (negate_option)
+ ++cp;
for (int i = 0; i < noptions; ++i)
if (strncmp (cp, options[i].str, options[i].len) == 0)
{
- if (options[i].clear)
- parser->template.options &= options[i].flag;
+ if (negate_option)
+ parser->template.options &= ~options[i].flag;
else
parser->template.options |= options[i].flag;
break;
diff --git a/resolv/tst-resolv-res_init-skeleton.c b/resolv/tst-resolv-res_init-skeleton.c
index 6bef62cde2cbf8cd..d3a19eb305d41467 100644
--- a/resolv/tst-resolv-res_init-skeleton.c
+++ b/resolv/tst-resolv-res_init-skeleton.c
@@ -679,6 +679,16 @@ struct test_case test_cases[] =
"; nameserver[0]: [192.0.2.1]:53\n",
.res_options = "attempts:5 ndots:3 edns0 ",
},
+ {.name = "RES_OPTIONS can clear flags",
+ .conf = "options ndots:2 use-vc no-aaaa edns0\n"
+ "nameserver 192.0.2.1\n",
+ .expected = "options ndots:3 use-vc\n"
+ "search example.com\n"
+ "; search[0]: example.com\n"
+ "nameserver 192.0.2.1\n"
+ "; nameserver[0]: [192.0.2.1]:53\n",
+ .res_options = "ndots:3 -edns0 -no-aaaa",
+ },
{.name = "many search list entries (bug 19569)",
.conf = "nameserver 192.0.2.1\n"
"search corp.example.com support.example.com"