From: Josh Triplett josh@joshtriplett.org
stable inclusion from linux-4.19.196 commit 51c0007f4c6b88f22c2a5bfb099d7654f0db973c
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[ 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 josh@joshtriplett.org Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- net/ipv4/ipconfig.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/net/ipv4/ipconfig.c b/net/ipv4/ipconfig.c index 88212615bf4ce..58719b9635d90 100644 --- a/net/ipv4/ipconfig.c +++ b/net/ipv4/ipconfig.c @@ -866,7 +866,7 @@ 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) { @@ -915,12 +915,15 @@ 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])