Add a "typed_var" abstraction to implement lvalue access in C.

Right now, this has been done at a high level by confparse.c, but it
makes more sense to lower it.

This API is radically un-typesafe as it stands; we'll be wrapping it
in a safer API as we do #30914 and lower the struct manipulation
code as well.

Closes ticket 30864.

1 files changed, 28 insertions, 321 deletions

diff --git a/src/app/config/confparse.c b/src/app/config/confparse.c
index 296e7c2a39..bc2ab24e4f 100644
--- a/src/app/config/confparse.c
+++ b/src/app/config/confparse.c
@@ -30,6 +30,8 @@
 #include "lib/container/bitarray.h"
 #include "lib/encoding/confline.h"
 
+#include "lib/confmgt/typedvar.h"
+
 static void config_reset(const config_format_t *fmt, void *options,
                          const config_var_t *var, int use_defaults);
 
@@ -160,7 +162,6 @@ static int
 config_assign_value(const config_format_t *fmt, void *options,
                     config_line_t *c, char **msg)
 {
-  int i, ok;
   const config_var_t *var;
   void *lvalue;
 
@@ -168,144 +169,14 @@ config_assign_value(const config_format_t *fmt, void *options,
 
   var = config_find_option(fmt, c->key);
   tor_assert(var);
+  tor_assert(!strcmp(c->key, var->name));
 
   lvalue = STRUCT_VAR_P(options, var->var_offset);
 
-  switch (var->type) {
-
-  case CONFIG_TYPE_INT:
-  case CONFIG_TYPE_POSINT:
-    i = (int)tor_parse_long(c->value, 10,
-                            var->type==CONFIG_TYPE_INT ? INT_MIN : 0,
-                            INT_MAX,
-                            &ok, NULL);
-    if (!ok) {
-      tor_asprintf(msg,
-          "Int keyword '%s %s' is malformed or out of bounds.",
-          c->key, c->value);
-      return -1;
-    }
-    *(int *)lvalue = i;
-    break;
-
-  case CONFIG_TYPE_UINT64: {
-    uint64_t u64 = tor_parse_uint64(c->value, 10,
-                                    0, UINT64_MAX, &ok, NULL);
-    if (!ok) {
-      tor_asprintf(msg,
-          "uint64 keyword '%s %s' is malformed or out of bounds.",
-          c->key, c->value);
-      return -1;
-    }
-    *(uint64_t *)lvalue = u64;
-    break;
-  }
+  if (var->type == CONFIG_TYPE_ROUTERSET) {
+    // XXXX make the backend extensible so that we don't have to
+    // XXXX handle ROUTERSET specially.
 
-  case CONFIG_TYPE_CSV_INTERVAL: {
-    /* We used to have entire smartlists here.  But now that all of our
-     * download schedules use exponential backoff, only the first part
-     * matters. */
-    const char *comma = strchr(c->value, ',');
-    const char *val = c->value;
-    char *tmp = NULL;
-    if (comma) {
-      tmp = tor_strndup(c->value, comma - c->value);
-      val = tmp;
-    }
-
-    i = config_parse_interval(val, &ok);
-    if (!ok) {
-      tor_asprintf(msg,
-          "Interval '%s %s' is malformed or out of bounds.",
-          c->key, c->value);
-      tor_free(tmp);
-      return -1;
-    }
-    *(int *)lvalue = i;
-    tor_free(tmp);
-    break;
-  }
-
-  case CONFIG_TYPE_INTERVAL: {
-    i = config_parse_interval(c->value, &ok);
-    if (!ok) {
-      tor_asprintf(msg,
-          "Interval '%s %s' is malformed or out of bounds.",
-          c->key, c->value);
-      return -1;
-    }
-    *(int *)lvalue = i;
-    break;
-  }
-
-  case CONFIG_TYPE_MSEC_INTERVAL: {
-    i = config_parse_msec_interval(c->value, &ok);
-    if (!ok) {
-      tor_asprintf(msg,
-          "Msec interval '%s %s' is malformed or out of bounds.",
-          c->key, c->value);
-      return -1;
-    }
-    *(int *)lvalue = i;
-    break;
-  }
-
-  case CONFIG_TYPE_MEMUNIT: {
-    uint64_t u64 = config_parse_memunit(c->value, &ok);
-    if (!ok) {
-      tor_asprintf(msg,
-          "Value '%s %s' is malformed or out of bounds.",
-          c->key, c->value);
-      return -1;
-    }
-    *(uint64_t *)lvalue = u64;
-    break;
-  }
-
-  case CONFIG_TYPE_BOOL:
-    i = (int)tor_parse_long(c->value, 10, 0, 1, &ok, NULL);
-    if (!ok) {
-      tor_asprintf(msg,
-          "Boolean '%s %s' expects 0 or 1.",
-          c->key, c->value);
-      return -1;
-    }
-    *(int *)lvalue = i;
-    break;
-
-  case CONFIG_TYPE_AUTOBOOL:
-    if (!strcasecmp(c->value, "auto"))
-      *(int *)lvalue = -1;
-    else if (!strcmp(c->value, "0"))
-      *(int *)lvalue = 0;
-    else if (!strcmp(c->value, "1"))
-      *(int *)lvalue = 1;
-    else {
-      tor_asprintf(msg, "Boolean '%s %s' expects 0, 1, or 'auto'.",
-                   c->key, c->value);
-      return -1;
-    }
-    break;
-
-  case CONFIG_TYPE_STRING:
-  case CONFIG_TYPE_FILENAME:
-    tor_free(*(char **)lvalue);
-    *(char **)lvalue = tor_strdup(c->value);
-    break;
-
-  case CONFIG_TYPE_DOUBLE:
-    *(double *)lvalue = atof(c->value);
-    break;
-
-  case CONFIG_TYPE_ISOTIME:
-    if (parse_iso_time(c->value, (time_t *)lvalue)) {
-      tor_asprintf(msg,
-          "Invalid time '%s' for keyword '%s'", c->value, c->key);
-      return -1;
-    }
-    break;
-
-  case CONFIG_TYPE_ROUTERSET:
     if (*(routerset_t**)lvalue) {
       routerset_free(*(routerset_t**)lvalue);
     }
@@ -315,50 +186,10 @@ config_assign_value(const config_format_t *fmt, void *options,
                    c->value, c->key);
       return -1;
     }
-    break;
-
-  case CONFIG_TYPE_CSV:
-    if (*(smartlist_t**)lvalue) {
-      SMARTLIST_FOREACH(*(smartlist_t**)lvalue, char *, cp, tor_free(cp));
-      smartlist_clear(*(smartlist_t**)lvalue);
-    } else {
-      *(smartlist_t**)lvalue = smartlist_new();
-    }
-
-    smartlist_split_string(*(smartlist_t**)lvalue, c->value, ",",
-                           SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 0);
-    break;
-
-  case CONFIG_TYPE_LINELIST:
-  case CONFIG_TYPE_LINELIST_S:
-    {
-      config_line_t *lastval = *(config_line_t**)lvalue;
-      if (lastval && lastval->fragile) {
-        if (c->command != CONFIG_LINE_APPEND) {
-          config_free_lines(lastval);
-          *(config_line_t**)lvalue = NULL;
-        } else {
-          lastval->fragile = 0;
-        }
-      }
-
-      config_line_append((config_line_t**)lvalue, c->key, c->value);
-    }
-    break;
-  case CONFIG_TYPE_OBSOLETE:
-    log_warn(LD_CONFIG, "Skipping obsolete configuration option '%s'", c->key);
-    break;
-  case CONFIG_TYPE_LINELIST_V:
-    tor_asprintf(msg,
-        "You may not provide a value for virtual option '%s'", c->key);
-    return -1;
-    // LCOV_EXCL_START
-  default:
-    tor_assert_unreached();
-    break;
-    // LCOV_EXCL_STOP
+    return 0;
   }
-  return 0;
+
+  return typed_var_kvassign(lvalue, c, msg, var->type);
 }
 
 /** Mark every linelist in <b>options</b> "fragile", so that fresh assignments
@@ -544,100 +375,15 @@ config_get_assigned_option(const config_format_t *fmt, const void *options,
   }
   value = STRUCT_VAR_P(options, var->var_offset);
 
-  result = tor_malloc_zero(sizeof(config_line_t));
-  result->key = tor_strdup(var->name);
-  switch (var->type)
-    {
-    case CONFIG_TYPE_STRING:
-    case CONFIG_TYPE_FILENAME:
-      if (*(char**)value) {
-        result->value = tor_strdup(*(char**)value);
-      } else {
-        tor_free(result->key);
-        tor_free(result);
-        return NULL;
-      }
-      break;
-    case CONFIG_TYPE_ISOTIME:
-      if (*(time_t*)value) {
-        result->value = tor_malloc(ISO_TIME_LEN+1);
-        format_iso_time(result->value, *(time_t*)value);
-      } else {
-        tor_free(result->key);
-        tor_free(result);
-      }
-      escape_val = 0; /* Can't need escape. */
-      break;
-    case CONFIG_TYPE_CSV_INTERVAL:
-    case CONFIG_TYPE_INTERVAL:
-    case CONFIG_TYPE_MSEC_INTERVAL:
-    case CONFIG_TYPE_POSINT:
-    case CONFIG_TYPE_INT:
-      /* This means every or_options_t uint or bool element
-       * needs to be an int. Not, say, a uint16_t or char. */
-      tor_asprintf(&result->value, "%d", *(int*)value);
-      escape_val = 0; /* Can't need escape. */
-      break;
-    case CONFIG_TYPE_UINT64: /* Fall through */
-    case CONFIG_TYPE_MEMUNIT:
-      tor_asprintf(&result->value, "%"PRIu64,
-                   (*(uint64_t*)value));
-      escape_val = 0; /* Can't need escape. */
-      break;
-    case CONFIG_TYPE_DOUBLE:
-      tor_asprintf(&result->value, "%f", *(double*)value);
-      escape_val = 0; /* Can't need escape. */
-      break;
-
-    case CONFIG_TYPE_AUTOBOOL:
-      if (*(int*)value == -1) {
-        result->value = tor_strdup("auto");
-        escape_val = 0;
-        break;
-      }
-      /* fall through */
-    case CONFIG_TYPE_BOOL:
-      result->value = tor_strdup(*(int*)value ? "1" : "0");
-      escape_val = 0; /* Can't need escape. */
-      break;
-    case CONFIG_TYPE_ROUTERSET:
-      result->value = routerset_to_string(*(routerset_t**)value);
-      break;
-    case CONFIG_TYPE_CSV:
-      if (*(smartlist_t**)value)
-        result->value =
-          smartlist_join_strings(*(smartlist_t**)value, ",", 0, NULL);
-      else
-        result->value = tor_strdup("");
-      break;
-    case CONFIG_TYPE_OBSOLETE:
-      log_fn(LOG_INFO, LD_CONFIG,
-             "You asked me for the value of an obsolete config option '%s'.",
-             key);
-      tor_free(result->key);
-      tor_free(result);
-      return NULL;
-    case CONFIG_TYPE_LINELIST_S:
-      tor_free(result->key);
-      tor_free(result);
-      result = config_lines_dup_and_filter(*(const config_line_t **)value,
-                                           key);
-      break;
-    case CONFIG_TYPE_LINELIST:
-    case CONFIG_TYPE_LINELIST_V:
-      tor_free(result->key);
-      tor_free(result);
-      result = config_lines_dup(*(const config_line_t**)value);
-      break;
-      // LCOV_EXCL_START
-    default:
-      tor_free(result->key);
-      tor_free(result);
-      log_warn(LD_BUG,"Unknown type %d for known key '%s'",
-               var->type, key);
-      return NULL;
-      // LCOV_EXCL_STOP
-    }
+  if (var->type == CONFIG_TYPE_ROUTERSET) {
+    // XXXX make the backend extensible so that we don't have to
+    // XXXX handle ROUTERSET specially.
+    result = tor_malloc_zero(sizeof(config_line_t));
+    result->key = tor_strdup(var->name);
+    result->value = routerset_to_string(*(routerset_t**)value);
+  } else {
+    result = typed_var_kvencode(var->name, value, var->type);
+  }
 
   if (escape_val) {
     config_line_t *line;
@@ -765,56 +511,17 @@ config_clear(const config_format_t *fmt, void *options,
 {
   void *lvalue = STRUCT_VAR_P(options, var->var_offset);
   (void)fmt; /* unused */
-  switch (var->type) {
-    case CONFIG_TYPE_STRING:
-    case CONFIG_TYPE_FILENAME:
-      tor_free(*(char**)lvalue);
-      break;
-    case CONFIG_TYPE_DOUBLE:
-      *(double*)lvalue = 0.0;
-      break;
-    case CONFIG_TYPE_ISOTIME:
-      *(time_t*)lvalue = 0;
-      break;
-    case CONFIG_TYPE_CSV_INTERVAL:
-    case CONFIG_TYPE_INTERVAL:
-    case CONFIG_TYPE_MSEC_INTERVAL:
-    case CONFIG_TYPE_POSINT:
-    case CONFIG_TYPE_INT:
-    case CONFIG_TYPE_BOOL:
-      *(int*)lvalue = 0;
-      break;
-    case CONFIG_TYPE_AUTOBOOL:
-      *(int*)lvalue = -1;
-      break;
-    case CONFIG_TYPE_UINT64:
-    case CONFIG_TYPE_MEMUNIT:
-      *(uint64_t*)lvalue = 0;
-      break;
-    case CONFIG_TYPE_ROUTERSET:
-      if (*(routerset_t**)lvalue) {
-        routerset_free(*(routerset_t**)lvalue);
-        *(routerset_t**)lvalue = NULL;
-      }
-      break;
-    case CONFIG_TYPE_CSV:
-      if (*(smartlist_t**)lvalue) {
-        SMARTLIST_FOREACH(*(smartlist_t **)lvalue, char *, cp, tor_free(cp));
-        smartlist_free(*(smartlist_t **)lvalue);
-        *(smartlist_t **)lvalue = NULL;
-      }
-      break;
-    case CONFIG_TYPE_LINELIST:
-    case CONFIG_TYPE_LINELIST_S:
-      config_free_lines(*(config_line_t **)lvalue);
-      *(config_line_t **)lvalue = NULL;
-      break;
-    case CONFIG_TYPE_LINELIST_V:
-      /* handled by linelist_s. */
-      break;
-    case CONFIG_TYPE_OBSOLETE:
-      break;
+  if (var->type == CONFIG_TYPE_ROUTERSET) {
+    // XXXX make the backend extensible so that we don't have to
+    // XXXX handle ROUTERSET specially.
+    if (*(routerset_t**)lvalue) {
+      routerset_free(*(routerset_t**)lvalue);
+      *(routerset_t**)lvalue = NULL;
+    }
+    return;
   }
+
+  typed_var_free(lvalue, var->type);
 }
 
 /** Clear the option indexed by <b>var</b> in <b>options</b>. Then if