From 860d2764dd7ce683c0cfeec1ed60dee0c1f2b443 Mon Sep 17 00:00:00 2001 From: Stefano Brivio Date: Fri, 8 Mar 2024 00:12:19 +0100 Subject: [PATCH] conf: Don't warn if nameservers were found, but won't be advertised Starting from commit 3a2afde87dd1 ("conf, udp: Drop mostly duplicated dns_send arrays, rename related fields"), we won't add to c->ip4.dns and c->ip6.dns nameservers that can't be used by the guest or container, and we won't advertise them. However, the fact that we don't advertise any nameserver doesn't mean that we didn't find any, and we should warn only if we couldn't find any. This is particularly relevant in case both --dns-forward and --no-map-gw are passed, and a single loopback address is listed in /etc/resolv.conf: we'll forward queries directed to the address specified by --dns-forward to the loopback address we found, we won't advertise that address, so we shouldn't warn: this is a perfectly legitimate usage. Reported-by: Paul Holzinger Link: https://github.com/containers/podman/issues/19213 Fixes: 3a2afde87dd1 ("conf, udp: Drop mostly duplicated dns_send arrays, rename related fields") Signed-off-by: Stefano Brivio Tested-by: Paul Holzinger --- conf.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/conf.c b/conf.c index 4a783b8..c50c039 100644 --- a/conf.c +++ b/conf.c @@ -399,6 +399,7 @@ static void get_dns(struct ctx *c) int dns4_set, dns6_set, dnss_set, dns_set, fd; struct fqdn *s = c->dns_search; struct lineread resolvconf; + unsigned int added = 0; char *line, *end; const char *p; int line_len; @@ -427,13 +428,17 @@ static void get_dns(struct ctx *c) if (!dns4_set && dns4 - &c->ip4.dns[0] < ARRAY_SIZE(c->ip4.dns) - 1 - && inet_pton(AF_INET, p + 1, &dns4_tmp)) + && inet_pton(AF_INET, p + 1, &dns4_tmp)) { add_dns4(c, &dns4_tmp, &dns4); + added++; + } if (!dns6_set && dns6 - &c->ip6.dns[0] < ARRAY_SIZE(c->ip6.dns) - 1 - && inet_pton(AF_INET6, p + 1, &dns6_tmp)) + && inet_pton(AF_INET6, p + 1, &dns6_tmp)) { add_dns6(c, &dns6_tmp, &dns6); + added++; + } } else if (!dnss_set && strstr(line, "search ") == line && s == c->dns_search) { end = strpbrk(line, "\n"); @@ -459,7 +464,7 @@ static void get_dns(struct ctx *c) close(fd); out: - if (!dns_set && dns4 == c->ip4.dns && dns6 == c->ip6.dns) + if (!dns_set && !added) warn("Couldn't get any nameserver address"); }