From c89764c0633670ef28166c70d03bc593f4a1179f Mon Sep 17 00:00:00 2001 From: Aaro Koskinen Date: Fri, 8 Feb 2019 16:30:24 +0100 Subject: [PATCH] sysctl: fix compatibility with procps sysctl Busybox sysctl is incompatible with procps when '.' appears in directory name, mostly happens with VLANs. busybox syntax (since 2008): net.ipv4.conf.eth0.100.mc_forwarding procps syntax (since 2002): net.ipv4.conf.eth0/100.mc_forwarding (supported by both: net/ipv4/conf/eth0.100/mc_forwarding) Use procps syntax for output; for input, allow both. function old new delta sysctl_dots_to_slashes 86 143 +57 sysctl_act_on_setting 443 453 +10 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 2/0 up/down: 67/0) Total: 67 bytes Signed-off-by: Aaro Koskinen Signed-off-by: Denys Vlasenko --- procps/sysctl.c | 28 ++++++++++++++++++++++++++-- 1 file changed, 26 insertions(+), 2 deletions(-) diff --git a/procps/sysctl.c b/procps/sysctl.c index 5303460f9..6d77185ca 100644 --- a/procps/sysctl.c +++ b/procps/sysctl.c @@ -56,9 +56,32 @@ enum { static void sysctl_dots_to_slashes(char *name) { - char *cptr, *last_good, *end; + char *cptr, *last_good, *end, *slash; char end_ch; + end = strchrnul(name, '='); + + slash = strchrnul(name, '/'); + if (slash < end + && strchrnul(name, '.') < slash + ) { + /* There are both dots and slashes, and 1st dot is + * before 1st slash. + * (IOW: not raw, unmangled a/b/c.d format) + * + * procps supports this syntax for names with dots: + * net.ipv4.conf.eth0/100.mc_forwarding + * (dots and slashes are simply swapped) + */ + while (end != name) { + end--; + if (*end == '.') *end = '/'; + else if (*end == '/') *end = '.'; + } + return; + } + /* else: use our old behavior: */ + /* Convert minimum number of '.' to '/' so that * we end up with existing file's name. * @@ -77,7 +100,6 @@ static void sysctl_dots_to_slashes(char *name) * * To set up testing: modprobe 8021q; vconfig add eth0 100 */ - end = strchrnul(name, '='); end_ch = *end; *end = '.'; /* trick the loop into trying full name too */ @@ -114,6 +136,8 @@ static int sysctl_act_on_setting(char *setting) while (*cptr) { if (*cptr == '/') *cptr = '.'; + else if (*cptr == '.') + *cptr = '/'; cptr++; }