From: Josh Triplett Date: Wed, 2 Jun 2021 01:38:41 +0000 (-0700) Subject: net: ipconfig: Don't override command-line hostnames or domains X-Git-Tag: v4.4.274~47 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=61ec5a0e7a1809c128d268971ef0151b7168793c;p=thirdparty%2Fkernel%2Fstable.git net: ipconfig: Don't override command-line hostnames or domains [ Upstream commit b508d5fb69c2211a1b860fc058aafbefc3b3c3cd ] If the user specifies a hostname or domain name as part of the ip= command-line option, preserve it and don't overwrite it with one supplied by DHCP/BOOTP. For instance, ip=::::myhostname::dhcp will use "myhostname" rather than ignoring and overwriting it. Fix the comment on ic_bootp_string that suggests it only copies a string "if not already set"; it doesn't have any such logic. Signed-off-by: Josh Triplett Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- diff --git a/net/ipv4/ipconfig.c b/net/ipv4/ipconfig.c index 60f564db25a3d..173777aa5add8 100644 --- a/net/ipv4/ipconfig.c +++ b/net/ipv4/ipconfig.c @@ -890,7 +890,7 @@ static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_d /* - * Copy BOOTP-supplied string if not already set. + * Copy BOOTP-supplied string */ static int __init ic_bootp_string(char *dest, char *src, int len, int max) { @@ -941,12 +941,15 @@ static void __init ic_do_bootp_ext(u8 *ext) } break; case 12: /* Host name */ - ic_bootp_string(utsname()->nodename, ext+1, *ext, - __NEW_UTS_LEN); - ic_host_name_set = 1; + if (!ic_host_name_set) { + ic_bootp_string(utsname()->nodename, ext+1, *ext, + __NEW_UTS_LEN); + ic_host_name_set = 1; + } break; case 15: /* Domain name (DNS) */ - ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain)); + if (!ic_domain[0]) + ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain)); break; case 17: /* Root path */ if (!root_server_path[0])