[PATCH v2 2/4] seccomp: Configurable separator for the actions_logged string

Tyler Hicks
2018-05-02T15:53:18Z

The function that converts a bitmask of seccomp actions that are
allowed to be logged is currently only used for constructing the display
string for the kernel.seccomp.actions_logged sysctl. That string wants a
space character to be used for the separator between actions.

A future patch will make use of the same function for building a string
that will be sent to the audit subsystem for tracking modifications to
the kernel.seccomp.actions_logged sysctl. That string will need to use a
comma as a separator. This patch allows the separator character to be
configurable to meet both needs.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
---
kernel/seccomp.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index f4afe67..b36ac1e 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -1135,10 +1135,11 @@ static const struct seccomp_log_name seccomp_log_names[] = {
};

static bool seccomp_names_from_actions_logged(char *names, size_t size,
- u32 actions_logged)
+ u32 actions_logged,
+ const char *sep)
{
const struct seccomp_log_name *cur;
- bool append_space = false;
+ bool append_sep = false;

for (cur = seccomp_log_names; cur->name && size; cur++) {
ssize_t ret;
@@ -1146,15 +1147,15 @@ static bool seccomp_names_from_actions_logged(char *names, size_t size,
if (!(actions_logged & cur->log))
continue;

- if (append_space) {
- ret = strscpy(names, " ", size);
+ if (append_sep) {
+ ret = strscpy(names, sep, size);
if (ret < 0)
return false;

names += ret;
size -= ret;
} else
- append_space = true;
+ append_sep = true;

ret = strscpy(names, cur->name, size);
if (ret < 0)
@@ -1208,7 +1209,7 @@ static int read_actions_logged(struct ctl_table *ro_table, void __user *buffer,
memset(names, 0, sizeof(names));

if (!seccomp_names_from_actions_logged(names, sizeof(names),
- seccomp_actions_logged))
+ seccomp_actions_logged, " "))
return -EINVAL;

table = *ro_table;
--
2.7.4