diff --git a/doc/lxc.container.conf.sgml.in b/doc/lxc.container.conf.sgml.in
index 21d9cfcc1..8c14d1507 100644
--- a/doc/lxc.container.conf.sgml.in
+++ b/doc/lxc.container.conf.sgml.in
@@ -1389,6 +1389,34 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+
+ Sysctl
+
+ Configure kernel parameters for the container.
+
+
+
+
+
+
+
+
+ Specify the kernel parameters to be set. The parameters available
+ are those listed under /proc/sys/.
+ Note that not all sysctls are namespaced.Changing Non-namespaced
+ sysctls will cause the system-wide setting to be modified.
+
+ sysctl
+ 8
+ .
+ If used with no value, lxc will clear the parameters specified up
+ to this point.
+
+
+
+
+
+
Apparmor profile
diff --git a/src/lxc/conf.c b/src/lxc/conf.c
index aaed68297..c59f28706 100644
--- a/src/lxc/conf.c
+++ b/src/lxc/conf.c
@@ -2366,6 +2366,38 @@ int setup_resource_limits(struct lxc_list *limits, pid_t pid) {
return 0;
}
+int setup_sysctl_parameters(struct lxc_list *sysctls)
+{
+ struct lxc_list *it;
+ struct lxc_sysctl *elem;
+ char *tmp = NULL;
+ char filename[MAXPATHLEN] = {0};
+ int ret = 0;
+
+ lxc_list_for_each(it, sysctls) {
+ elem = it->elem;
+ tmp = lxc_string_replace(".", "/", elem->key);
+ if (!tmp) {
+ ERROR("Failed to replace key %s", elem->key);
+ return -1;
+ }
+
+ ret = snprintf(filename, sizeof(filename), "/proc/sys/%s", tmp);
+ free(tmp);
+ if (ret < 0 || (size_t)ret >= sizeof(filename)) {
+ ERROR("Error setting up sysctl parameters path");
+ return -1;
+ }
+
+ ret = lxc_write_to_file(filename, elem->value, strlen(elem->value), false);
+ if (ret < 0) {
+ ERROR("Failed to setup sysctl parameters %s to %s", elem->key, elem->value);
+ return -1;
+ }
+ }
+ return 0;
+}
+
static char *default_rootfs_mount = LXCROOTFSMOUNT;
struct lxc_conf *lxc_conf_init(void)
@@ -2416,6 +2448,7 @@ struct lxc_conf *lxc_conf_init(void)
lxc_list_init(&new->aliens);
lxc_list_init(&new->environment);
lxc_list_init(&new->limits);
+ lxc_list_init(&new->sysctls);
for (i = 0; i < NUM_LXC_HOOKS; i++)
lxc_list_init(&new->hooks[i]);
lxc_list_init(&new->groups);
@@ -3164,6 +3197,15 @@ int lxc_setup(struct lxc_handler *handler)
return -1;
}
+ /* set sysctl value to a path under /proc/sys as determined from the key.
+ * For e.g. net.ipv4.ip_forward translated to /proc/sys/net/ipv4/ip_forward.
+ */
+ if (!lxc_list_empty(&lxc_conf->sysctls)) {
+ ret = setup_sysctl_parameters(&lxc_conf->sysctls);
+ if (ret < 0)
+ return -1;
+ }
+
if (!lxc_list_empty(&lxc_conf->keepcaps)) {
if (!lxc_list_empty(&lxc_conf->caps)) {
ERROR("Container requests lxc.cap.drop and lxc.cap.keep: either use lxc.cap.drop or lxc.cap.keep, not both.");
@@ -3315,6 +3357,32 @@ int lxc_clear_limits(struct lxc_conf *c, const char *key)
return 0;
}
+int lxc_clear_sysctls(struct lxc_conf *c, const char *key)
+{
+ struct lxc_list *it, *next;
+ bool all = false;
+ const char *k = NULL;
+
+ if (strcmp(key, "lxc.sysctl") == 0)
+ all = true;
+ else if (strncmp(key, "lxc.sysctl.", sizeof("lxc.sysctl.") - 1) == 0)
+ k = key + sizeof("lxc.sysctl.") - 1;
+ else
+ return -1;
+
+ lxc_list_for_each_safe(it, &c->sysctls, next) {
+ struct lxc_sysctl *elem = it->elem;
+ if (!all && strcmp(elem->key, k) != 0)
+ continue;
+ lxc_list_del(it);
+ free(elem->key);
+ free(elem->value);
+ free(elem);
+ free(it);
+ }
+ return 0;
+}
+
int lxc_clear_groups(struct lxc_conf *c)
{
struct lxc_list *it,*next;
@@ -3454,6 +3522,7 @@ void lxc_conf_free(struct lxc_conf *conf)
lxc_clear_aliens(conf);
lxc_clear_environment(conf);
lxc_clear_limits(conf, "lxc.prlimit");
+ lxc_clear_sysctls(conf, "lxc.sysctl");
free(conf->cgroup_meta.dir);
free(conf->cgroup_meta.controllers);
free(conf);
diff --git a/src/lxc/conf.h b/src/lxc/conf.h
index 479f38d7e..e60a6151f 100644
--- a/src/lxc/conf.h
+++ b/src/lxc/conf.h
@@ -95,6 +95,16 @@ enum idtype {
ID_TYPE_GID
};
+/*
+ * Defines a structure to configure kernel parameters at runtime.
+ * @key : the kernel parameters will be configured without the "lxc.sysctl" prefix
+ * @value : the value to set
+ */
+struct lxc_sysctl {
+ char *key;
+ char *value;
+};
+
/*
* id_map is an id map entry. Form in confile is:
* lxc.idmap = u 0 9800 100
@@ -370,6 +380,9 @@ struct lxc_conf {
/* A list of clients registered to be informed about a container state. */
struct lxc_list state_clients;
+
+ /* sysctls */
+ struct lxc_list sysctls;
};
int write_id_mapping(enum idtype idtype, pid_t pid, const char *buf,
@@ -428,5 +441,7 @@ extern unsigned long add_required_remount_flags(const char *s, const char *d,
extern int run_script(const char *name, const char *section, const char *script,
...);
extern int in_caplist(int cap, struct lxc_list *caps);
+extern int setup_sysctl_parameters(struct lxc_list *sysctls);
+extern int lxc_clear_sysctls(struct lxc_conf *c, const char *key);
#endif /* __LXC_CONF_H */
diff --git a/src/lxc/confile.c b/src/lxc/confile.c
index b4e3d1a1c..dba13d5ef 100644
--- a/src/lxc/confile.c
+++ b/src/lxc/confile.c
@@ -141,6 +141,7 @@ lxc_config_define(start);
lxc_config_define(tty_max);
lxc_config_define(tty_dir);
lxc_config_define(uts_name);
+lxc_config_define(sysctl);
static struct lxc_config_t config[] = {
/* REMOVE in LXC 3.0 */
@@ -241,6 +242,7 @@ static struct lxc_config_t config[] = {
{ "lxc.tty.dir", false, set_config_tty_dir, get_config_tty_dir, clr_config_tty_dir, },
{ "lxc.tty.max", false, set_config_tty_max, get_config_tty_max, clr_config_tty_max, },
{ "lxc.uts.name", false, set_config_uts_name, get_config_uts_name, clr_config_uts_name, },
+ { "lxc.sysctl", false, set_config_sysctl, get_config_sysctl, clr_config_sysctl, },
/* [START]: REMOVE IN LXC 3.0 */
{ "lxc.pts", true, set_config_pty_max, get_config_pty_max, clr_config_pty_max, },
@@ -1456,8 +1458,7 @@ static int set_config_prlimit(const char *key, const char *value,
}
/* find existing list element */
- lxc_list_for_each(iter, &lxc_conf->limits)
- {
+ lxc_list_for_each(iter, &lxc_conf->limits) {
limelem = iter->elem;
if (!strcmp(key, limelem->resource)) {
limelem->limit = limit;
@@ -1468,25 +1469,25 @@ static int set_config_prlimit(const char *key, const char *value,
/* allocate list element */
limlist = malloc(sizeof(*limlist));
if (!limlist)
- goto out;
+ goto on_error;
limelem = malloc(sizeof(*limelem));
if (!limelem)
- goto out;
+ goto on_error;
memset(limelem, 0, sizeof(*limelem));
limelem->resource = strdup(key);
if (!limelem->resource)
- goto out;
+ goto on_error;
limelem->limit = limit;
- limlist->elem = limelem;
+ lxc_list_add_elem(limlist, limelem);;
lxc_list_add_tail(&lxc_conf->limits, limlist);
return 0;
-out:
+on_error:
free(limlist);
if (limelem) {
free(limelem->resource);
@@ -1495,6 +1496,71 @@ out:
return -1;
}
+static int set_config_sysctl(const char *key, const char *value,
+ struct lxc_conf *lxc_conf, void *data)
+{
+ struct lxc_list *iter;
+ struct lxc_list *sysctl_list = NULL;
+ struct lxc_sysctl *sysctl_elem = NULL;
+ char *replace_value = NULL;
+
+ if (lxc_config_value_empty(value))
+ return lxc_clear_sysctls(lxc_conf, key);
+
+ if (strncmp(key, "lxc.sysctl.", sizeof("lxc.sysctl.") - 1) != 0)
+ return -1;
+
+ key += sizeof("lxc.sysctl.") - 1;
+
+ /* find existing list element */
+ lxc_list_for_each(iter, &lxc_conf->sysctls) {
+ sysctl_elem = iter->elem;
+ if (strcmp(key, sysctl_elem->key) == 0) {
+ replace_value = strdup(value);
+ if (!replace_value)
+ return -1;
+ free(sysctl_elem->value);
+ sysctl_elem->value = replace_value;
+ return 0;
+ }
+ }
+
+ /* allocate list element */
+ sysctl_list = malloc(sizeof(*sysctl_list));
+ if (!sysctl_list)
+ goto on_error;
+
+ sysctl_elem = malloc(sizeof(*sysctl_elem));
+ if (!sysctl_elem)
+ goto on_error;
+ memset(sysctl_elem, 0, sizeof(*sysctl_elem));
+
+ sysctl_elem->key = strdup(key);
+ if (!sysctl_elem->key)
+ goto on_error;
+
+ sysctl_elem->value = strdup(value);
+ if (!sysctl_elem->value)
+ goto on_error;
+
+ lxc_list_add_elem(sysctl_list, sysctl_elem);
+
+ lxc_list_add_tail(&lxc_conf->sysctls, sysctl_list);
+
+ return 0;
+
+on_error:
+ free(sysctl_list);
+ if (sysctl_elem) {
+ free(sysctl_elem->key);
+ free(sysctl_elem->value);
+ free(sysctl_elem);
+ }
+ return -1;
+
+
+}
+
static int set_config_idmaps(const char *key, const char *value,
struct lxc_conf *lxc_conf, void *data)
{
@@ -3310,6 +3376,43 @@ static int get_config_prlimit(const char *key, char *retv, int inlen,
return fulllen;
}
+/* If you ask for a specific value, i.e. lxc.sysctl.net.ipv4.ip_forward, then just the value
+ * will be printed. If you ask for 'lxc.sysctl', then all sysctl entries will be
+ * printed, in 'lxc.sysctl.key = value' format.
+ */
+static int get_config_sysctl(const char *key, char *retv, int inlen,
+ struct lxc_conf *c, void *data)
+{
+ int len;
+ struct lxc_list *it;
+ int fulllen = 0;
+ bool get_all = false;
+
+ if (!retv)
+ inlen = 0;
+ else
+ memset(retv, 0, inlen);
+
+ if (strcmp(key, "lxc.sysctl") == 0)
+ get_all = true;
+ else if (strncmp(key, "lxc.sysctl.", sizeof("lxc.sysctl.") - 1) == 0)
+ key += sizeof("lxc.sysctl.") - 1;
+ else
+ return -1;
+
+ lxc_list_for_each(it, &c->sysctls) {
+ struct lxc_sysctl *elem = it->elem;
+ if (get_all) {
+ strprint(retv, inlen, "lxc.sysctl.%s = %s\n",
+ elem->key, elem->value);
+ } else if (strcmp(elem->key, key) == 0) {
+ strprint(retv, inlen, "%s", elem->value);
+ }
+ }
+
+ return fulllen;
+}
+
static int get_config_noop(const char *key, char *retv, int inlen,
struct lxc_conf *c, void *data)
{
@@ -3687,6 +3790,12 @@ static inline int clr_config_prlimit(const char *key, struct lxc_conf *c,
return lxc_clear_limits(c, key);
}
+static inline int clr_config_sysctl(const char *key, struct lxc_conf *c,
+ void *data)
+{
+ return lxc_clear_sysctls(c, key);
+}
+
static inline int clr_config_includefiles(const char *key, struct lxc_conf *c,
void *data)
{
diff --git a/src/tests/get_item.c b/src/tests/get_item.c
index e0fd7b603..7a15c1c89 100644
--- a/src/tests/get_item.c
+++ b/src/tests/get_item.c
@@ -34,8 +34,9 @@
int main(int argc, char *argv[])
{
- int ret = EXIT_FAILURE;
+ int ret;
struct lxc_container *c;
+ int fret = EXIT_FAILURE;
char v1[2], v2[256], v3[2048];
if ((c = lxc_container_new("testxyz", NULL)) == NULL) {
@@ -243,6 +244,71 @@ int main(int argc, char *argv[])
}
printf("lxc.limit returned %d %s\n", ret, v3);
+#define SYSCTL_SOMAXCONN "lxc.sysctl.net.core.somaxconn = 256\n"
+#define ALL_SYSCTLS "lxc.sysctl.net.ipv4.ip_forward = 1\n" SYSCTL_SOMAXCONN
+
+ ret = c->get_config_item(c, "lxc.sysctl", v3, 2047);
+ if (ret != 0) {
+ fprintf(stderr, "%d: get_config_item(sysctl) returned %d\n", __LINE__, ret);
+ goto out;
+ }
+
+ if (!c->set_config_item(c, "lxc.sysctl.net.ipv4.ip_forward", "1")) {
+ fprintf(stderr, "%d: failed to set lxc.sysctl.net.ipv4.ip_forward\n", __LINE__);
+ goto out;
+ }
+ ret = c->get_config_item(c, "lxc.sysctl.net.ipv4.ip_forward", v2, 255);
+ if (ret < 0) {
+ fprintf(stderr, "%d: get_config_item(lxc.sysctl.net.ipv4.ip_forward) returned %d\n", __LINE__, ret);
+ goto out;
+ }
+ if (strcmp(v2, "1")) {
+ fprintf(stderr, "%d: lxc.sysctl.net.ipv4.ip_forward returned wrong value: %d %s not 1\n", __LINE__, ret, v2);
+ goto out;
+ }
+ printf("lxc.sysctl.net.ipv4.ip_forward returned %d %s\n", ret, v2);
+
+ if (!c->set_config_item(c, "lxc.sysctl.net.core.somaxconn", "256")) {
+ fprintf(stderr, "%d: failed to set lxc.sysctl.net.core.somaxconn\n", __LINE__);
+ goto out;
+ }
+ ret = c->get_config_item(c, "lxc.sysctl.net.core.somaxconn", v2, 255);
+ if (ret < 0) {
+ fprintf(stderr, "%d: get_config_item(lxc.sysctl.net.core.somaxconn) returned %d\n", __LINE__, ret);
+ goto out;
+ }
+ if (strcmp(v2, "256")) {
+ fprintf(stderr, "%d: lxc.sysctl.net.core.somaxconn returned wrong value: %d %s not 256\n", __LINE__, ret, v2);
+ goto out;
+ }
+ printf("lxc.sysctl.net.core.somaxconn returned %d %s\n", ret, v2);
+
+ ret = c->get_config_item(c, "lxc.sysctl", v3, 2047);
+ if (ret != sizeof(ALL_SYSCTLS)-1) {
+ fprintf(stderr, "%d: get_config_item(sysctl) returned %d\n", __LINE__, ret);
+ goto out;
+ }
+ if (strcmp(v3, ALL_SYSCTLS)) {
+ fprintf(stderr, "%d: lxc.sysctl returned wrong value: %d %s not %d %s\n", __LINE__, ret, v3, (int)sizeof(ALL_SYSCTLS) - 1, ALL_SYSCTLS);
+ goto out;
+ }
+ printf("lxc.sysctl returned %d %s\n", ret, v3);
+
+ if (!c->clear_config_item(c, "lxc.sysctl.net.ipv4.ip_forward")) {
+ fprintf(stderr, "%d: failed clearing lxc.sysctl.net.ipv4.ip_forward\n", __LINE__);
+ goto out;
+ }
+ ret = c->get_config_item(c, "lxc.sysctl", v3, 2047);
+ if (ret != sizeof(SYSCTL_SOMAXCONN) - 1) {
+ fprintf(stderr, "%d: get_config_item(sysctl) returned %d\n", __LINE__, ret);
+ goto out;
+ }
+ if (strcmp(v3, SYSCTL_SOMAXCONN)) {
+ fprintf(stderr, "%d: lxc.sysctl returned wrong value: %d %s not %d %s\n", __LINE__, ret, v3, (int)sizeof(SYSCTL_SOMAXCONN) - 1, SYSCTL_SOMAXCONN);
+ goto out;
+ }
+ printf("lxc.sysctl returned %d %s\n", ret, v3);
+
if (!c->set_config_item(c, "lxc.aa_profile", "unconfined")) {
fprintf(stderr, "%d: failed to set aa_profile\n", __LINE__);
goto out;
@@ -424,9 +490,9 @@ int main(int argc, char *argv[])
}
printf("All get_item tests passed\n");
- ret = EXIT_SUCCESS;
+ fret = EXIT_SUCCESS;
out:
c->destroy(c);
lxc_container_put(c);
- exit(ret);
+ exit(fret);
}
diff --git a/src/tests/parse_config_file.c b/src/tests/parse_config_file.c
index c679acc28..556d6d034 100644
--- a/src/tests/parse_config_file.c
+++ b/src/tests/parse_config_file.c
@@ -922,6 +922,13 @@ int main(int argc, char *argv[])
goto non_test_error;
}
+ /* lxc.sysctl */
+ if (set_get_compare_clear_save_load(c, "lxc.sysctl.net.core.somaxconn", "256", tmpf,
+ true) < 0) {
+ lxc_error("%s\n", "lxc.sysctl.net.core.somaxconn");
+ goto non_test_error;
+ }
+
/* REMOVE IN LXC 3.0
legacy lxc.limit.* key
*/