[PATCH] nss: Compare hostname case insensitive

There are some tools that convert hostname to lowercase before resolving it (e.g. ssh). In a way it makes sense because DNS is case insensitive and in case of ssh the lowercase version is then used to find matching record in its config file. However, our NSS module performs case sensitive comparison, which makes it useless with ssh. Just consider a machine named FooBar. Therefore, switch to case insensitive string comparison. Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1777873 Signed-off-by: Michal Privoznik <mprivozn@redhat.com> --- build-aux/syntax-check.mk | 2 +- tests/nsstest.c | 1 + tools/nss/libvirt_nss_leases.c | 2 +- tools/nss/libvirt_nss_macs.c | 2 +- 4 files changed, 4 insertions(+), 3 deletions(-) diff --git a/build-aux/syntax-check.mk b/build-aux/syntax-check.mk index 73f8a21c1b..f9f60c934c 100644 --- a/build-aux/syntax-check.mk +++ b/build-aux/syntax-check.mk @@ -1337,7 +1337,7 @@ sc_prohibit_enum_impl_with_vir_prefix_in_virsh: ## Exceptions ## ## ---------- ## -exclude_file_name_regexp--sc_avoid_strcase = ^tools/vsh\.h$$ +exclude_file_name_regexp--sc_avoid_strcase = ^tools/(vsh\.h|nss/libvirt_nss_(leases|macs)\.c)$$ exclude_file_name_regexp--sc_avoid_write = ^src/libvirt-stream\.c$$ diff --git a/tests/nsstest.c b/tests/nsstest.c index 2c2e57769b..a03f230452 100644 --- a/tests/nsstest.c +++ b/tests/nsstest.c @@ -173,6 +173,7 @@ mymain(void) # if !defined(LIBVIRT_NSS_GUEST) DO_TEST("fedora", AF_INET, "192.168.122.197", "192.168.122.198", "192.168.122.199", "192.168.122.3"); DO_TEST("gentoo", AF_INET, "192.168.122.254"); + DO_TEST("Gentoo", AF_INET, "192.168.122.254"); DO_TEST("gentoo", AF_INET6, "2001:1234:dead:beef::2"); DO_TEST("gentoo", AF_UNSPEC, "192.168.122.254"); DO_TEST("non-existent", AF_UNSPEC, NULL); diff --git a/tools/nss/libvirt_nss_leases.c b/tools/nss/libvirt_nss_leases.c index 536fcf8608..770dae8625 100644 --- a/tools/nss/libvirt_nss_leases.c +++ b/tools/nss/libvirt_nss_leases.c @@ -272,7 +272,7 @@ findLeasesParserEndMap(void *ctx) } } else { DEBUG("Check name '%s' vs '%s'", parser->name, NULLSTR(parser->entry.hostname)); - if (parser->entry.hostname && !strcmp(parser->name, parser->entry.hostname)) + if (parser->entry.hostname && !strcasecmp(parser->name, parser->entry.hostname)) found = true; } DEBUG("Found %d", found); diff --git a/tools/nss/libvirt_nss_macs.c b/tools/nss/libvirt_nss_macs.c index d4b165eef6..f45d149793 100644 --- a/tools/nss/libvirt_nss_macs.c +++ b/tools/nss/libvirt_nss_macs.c @@ -142,7 +142,7 @@ findMACsParserEndMap(void *ctx) if (parser->state != FIND_MACS_STATE_ENTRY) return 0; - if (!strcmp(parser->entry.name, parser->name)) { + if (!strcasecmp(parser->entry.name, parser->name)) { char **macs = realloc(*parser->macs, sizeof(char *) * ((*parser->nmacs) + parser->entry.nmacs)); if (!macs) -- 2.35.1

On Fri, May 27, 2022 at 11:06:46AM +0200, Michal Privoznik wrote:
There are some tools that convert hostname to lowercase before resolving it (e.g. ssh). In a way it makes sense because DNS is case insensitive and in case of ssh the lowercase version is then used to find matching record in its config file. However, our NSS module performs case sensitive comparison, which makes it useless with ssh. Just consider a machine named FooBar.
Therefore, switch to case insensitive string comparison.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1777873 Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>

On a Friday in 2022, Michal Privoznik wrote:
There are some tools that convert hostname to lowercase before resolving it (e.g. ssh). In a way it makes sense because DNS is case insensitive and in case of ssh the lowercase version is then used to find matching record in its config file. However, our NSS module performs case sensitive comparison, which makes it useless with ssh. Just consider a machine named FooBar.
Therefore, switch to case insensitive string comparison.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1777873 Signed-off-by: Michal Privoznik <mprivozn@redhat.com> --- build-aux/syntax-check.mk | 2 +- tests/nsstest.c | 1 + tools/nss/libvirt_nss_leases.c | 2 +- tools/nss/libvirt_nss_macs.c | 2 +- 4 files changed, 4 insertions(+), 3 deletions(-)
Reviewed-by: Ján Tomko <jtomko@redhat.com> Jano
participants (3)
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Ján Tomko
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Martin Kletzander
-
Michal Privoznik