allow sysctl config from env

config.c

@@ -79,6 +79,8 @@ typedef enum {
 #define UPDATE_TIME POLICY | TRAIL
 #define RUN_TIME UPDATE_TIME | META | CMD
 
+#define LEVEL_SYSCTL PV_ENTRY | UPDATE_TIME
+
 // default list
 #define CACHE_DEVMETADIR_DEF "/storage/cache/devmeta"
 #define CACHE_USRMETADIR_DEF "/storage/cache/meta"
@@ -696,30 +698,15 @@ static char *_get_value_policy(struct dl_list *config_list)
  return strdup(item);
 }
 
-static int _apply_config_sysctl(const char *key, const char *value,
- void *opaque)
+static int _set_config_sysctl_by_key(const char *key, const char *value)
 {
- const char *start = key + strlen("sysctl");
- char *path =
- calloc(strlen("/proc/sys") + strlen(start) + 1, sizeof(char));
-
+ char *path = pv_config_parser_sysctl_key(key);
  if (!path)
- return -1;
-
- sprintf(path, "%s", "/proc/sys");
-
- const char *next = start;
- char *p = path + strlen("/proc/sys");
-
- for (int i = 0; i < (int)strlen(start); ++i)
- p[i] = next[i] == '.' ? '/' : next[i];
+ return 0;
 
- errno = 0;
  int fd = open(path, O_WRONLY | O_SYNC);
  if (fd < 0) {
- pv_log(ERROR, "open failed for sysctl node %s with '%s'", path,
- strerror(errno));
-
+ pv_log(WARN, "cannot open '%s': %s", path, strerror(errno));
  free(path);
  return -1;
  }
@@ -728,7 +715,7 @@ static int _apply_config_sysctl(const char *key, const char *value,
  close(fd);
  free(path);
 
- return 0;
+ return 1;
 }
 
 static int pv_config_load_policy(const char *policy,
@@ -872,8 +859,13 @@ static struct pv_config_entry *_search_config_entry_by_alias(const char *alias)
 
 static int _set_config_by_key(const char *key, const char *value, void *opaque)
 {
- struct pv_config_entry *entry;
+ level_t *level = (level_t *)opaque;
+ if (*level & LEVEL_SYSCTL) {
+ if (_set_config_sysctl_by_key(key, value))
+ return 0;
+ }
 
+ struct pv_config_entry *entry;
  entry = _search_config_entry_by_key(key);
  if (!entry) {
  entry = _search_config_entry_by_alias(key);
@@ -885,7 +877,6 @@ static int _set_config_by_key(const char *key, const char *value, void *opaque)
  if (!entry)
  return 0;
 
- level_t *level = (level_t *)opaque;
  if (_set_config_by_entry(entry, value, *level)) {
  pv_log(WARN, "cannot set key '%s' in config", key);
  return 0;
@@ -898,8 +889,6 @@ static void _iterate_config_items(struct dl_list *items, level_t level)
 {
  level_t l = level;
  config_iterate_items(items, _set_config_by_key, (void *)&l);
- config_iterate_items_prefix(items, _apply_config_sysctl, "sysctl.",
- NULL);
 }
 
 static int pv_config_load_file(char *path)
@@ -1248,8 +1237,8 @@ int pv_config_init(char *path)
  }
 
  // default core_pattern, overridable by config
- _apply_config_sysctl("sysctl.kernel.core_pattern",
-  "|/lib/pv/pvcrash --skip", NULL);
+ _set_config_sysctl_by_key("PV_SYSCTL_KERNEL_CORE_PATTERN",
+  "|/lib/pv/pvcrash --skip");
 
  if (!path)
  path = PV_PANTAVISOR_CONFIG_PATH;

config_parser.c

@@ -25,12 +25,14 @@
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
+#include <ctype.h>
 
 #include <sys/types.h>
 #include <sys/stat.h>
 
 #include "config_parser.h"
 #include "utils/str.h"
+#include "utils/fs.h"
 
 #define MODULE_NAME "config_parser"
 #define pv_log(level, msg, ...) vlog(MODULE_NAME, level, msg, ##__VA_ARGS__)
@@ -283,3 +285,70 @@ void config_clear_items(struct dl_list *list)
  free(curr);
  }
 }
+
+static char *_parse_legacy_sysctl_key(const char *key)
+{
+ const char *start = key + strlen("sysctl");
+ char *path =
+ calloc(strlen("/proc/sys") + strlen(start) + 1, sizeof(char));
+ if (!path)
+ return NULL;
+
+ sprintf(path, "%s", "/proc/sys");
+
+ char *p = path + strlen("/proc/sys");
+
+ for (int i = 0; i < (int)strlen(start); ++i)
+ p[i] = start[i] == '.' ? '/' : start[i];
+
+ return path;
+}
+
+static char *_parse_sysctl_key(const char *key)
+{
+ const char *base = "/proc/sys/";
+ size_t baselen = strlen(base);
+
+ const char *k = key + strlen("PV_SYSCTL_");
+
+ char *path = calloc(baselen + strlen(k) + 1, sizeof(char));
+ if (!path)
+ return NULL;
+
+ sprintf(path, "%s%s", base, k);
+
+ char *p = path + baselen;
+ while (*p) {
+ if (*p == '_') {
+ // temporary \0 to evaluate if it is a dir
+ *p = '\0';
+ if (pv_fs_path_is_directory(path))
+ *p = '/';
+ else
+ *p = '_';
+ } else
+ *p = tolower(*p);
+ p++;
+ }
+
+ return path;
+}
+
+char *pv_config_parser_sysctl_key(const char *key)
+{
+ size_t keylen = strlen(key);
+
+ const char *lprefix = "sysctl";
+ size_t lprefixlen = strlen(lprefix);
+ if ((keylen > lprefixlen) &&
+ pv_str_startswith(lprefix, lprefixlen, key))
+ return _parse_legacy_sysctl_key(key);
+
+ const char *prefix = "PV_SYSCTL_";
+ size_t prefixlen = strlen(prefix);
+ if ((keylen > prefixlen) &&
+ pv_str_startswith_case(prefix, prefixlen, key))
+ return _parse_sysctl_key(key);
+
+ return NULL;
+}

config_parser.h

@@ -33,12 +33,12 @@ void config_iterate_items(struct dl_list *list,
  int (*action)(const char *key, const char *value,
  void *opaque),
  void *opaque);
-
 void config_iterate_items_prefix(struct dl_list *list,
  int (*action)(const char *key,
  const char *value, void *opaque),
  char *prefix, void *opaque);
-
 void config_clear_items(struct dl_list *list);
 
+char *pv_config_parser_sysctl_key(const char *key);
+
 #endif