ovn: Add address set support.

Update the OVN expression parser to support address sets. Previously, you could have a set of IP or MAC addresses in this form: {addr1, addr2, ..., addrN} This patch adds support for a bit of indirection where we can define a set of addresses and refer to them by name. $name This '$name' can be used in the expresssions like {addr1, addr2, $name, ... } {$name} $name A future patch will expose the ability to define address sets for use. Signed-off-by: Russell Bryant <[email protected]> Co-authored-by: Babu Shanmugam <[email protected]> Signed-off-by: Babu Shanmugam <[email protected]> [[email protected] made numerous small changes] Signed-off-by: Ben Pfaff <[email protected]>
grizax · Jul 3, 2016 · 2c5cbb1 · 2c5cbb1
1 parent eff49a5
commit 2c5cbb1
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Showing 8 changed files with 255 additions and 24 deletions.
diff --git a/ovn/controller/lflow.c b/ovn/controller/lflow.c
@@ -306,7 +306,7 @@ add_logical_flows(struct controller_ctx *ctx, const struct lport_index *lports,
         struct hmap matches;
         struct expr *expr;
 
-        expr = expr_parse_string(lflow->match, &symtab, &error);
+        expr = expr_parse_string(lflow->match, &symtab, NULL, &error);
         if (!error) {
             if (prereqs) {
                 expr = expr_combine(EXPR_T_AND, expr, prereqs);

diff --git a/ovn/lib/actions.c b/ovn/lib/actions.c
@@ -208,7 +208,7 @@ add_prerequisite(struct action_context *ctx, const char *prerequisite)
     struct expr *expr;
     char *error;
 
-    expr = expr_parse_string(prerequisite, ctx->ap->symtab, &error);
+    expr = expr_parse_string(prerequisite, ctx->ap->symtab, NULL, &error);
     ovs_assert(!error);
     ctx->prereqs = expr_combine(EXPR_T_AND, ctx->prereqs, expr);
 }

diff --git a/ovn/lib/expr.c b/ovn/lib/expr.c
@@ -409,6 +409,7 @@ expr_print(const struct expr *e)
 struct expr_context {
     struct lexer *lexer;        /* Lexer for pulling more tokens. */
     const struct shash *symtab; /* Symbol table. */
+    const struct shash *macros; /* Table of macros. */
     char *error;                /* Error, if any, otherwise NULL. */
     bool not;                   /* True inside odd number of NOT operators. */
 };
@@ -728,6 +729,33 @@ assign_constant_set_type(struct expr_context *ctx,
     }
 }
 
+static bool
+parse_macros(struct expr_context *ctx, struct expr_constant_set *cs,
+             size_t *allocated_values)
+{
+    struct expr_constant_set *addr_set
+        = shash_find_data(ctx->macros, ctx->lexer->token.s);
+    if (!addr_set) {
+        expr_syntax_error(ctx, "expecting address set name.");
+        return false;
+    }
+
+    if (!assign_constant_set_type(ctx, cs, EXPR_C_INTEGER)) {
+        return false;
+    }
+
+    size_t n_values = cs->n_values + addr_set->n_values;
+    if (n_values >= *allocated_values) {
+        cs->values = xrealloc(cs->values, n_values * sizeof *cs->values);
+        *allocated_values = n_values;
+    }
+    for (size_t i = 0; i < addr_set->n_values; i++) {
+        cs->values[cs->n_values++] = addr_set->values[i];
+    }
+
+    return true;
+}
+
 static bool
 parse_constant(struct expr_context *ctx, struct expr_constant_set *cs,
                size_t *allocated_values)
@@ -759,6 +787,12 @@ parse_constant(struct expr_context *ctx, struct expr_constant_set *cs,
         }
         lexer_get(ctx->lexer);
         return true;
+    } else if (ctx->lexer->token.type == LEX_T_MACRO) {
+        if (!parse_macros(ctx, cs, allocated_values)) {
+            return false;
+        }
+        lexer_get(ctx->lexer);
+        return true;
     } else {
         expr_syntax_error(ctx, "expecting constant.");
         return false;
@@ -808,6 +842,69 @@ expr_constant_set_destroy(struct expr_constant_set *cs)
     }
 }
 
+/* Adds a macro named 'name' to 'macros', replacing any existing macro with the
+ * given name. */
+void
+expr_macros_add(struct shash *macros, const char *name,
+                const char *const *values, size_t n_values)
+{
+    /* Replace any existing entry for this name. */
+    expr_macros_remove(macros, name);
+
+    struct expr_constant_set *cs = xzalloc(sizeof *cs);
+    cs->type = EXPR_C_INTEGER;
+    cs->in_curlies = true;
+    cs->n_values = 0;
+    cs->values = xmalloc(n_values * sizeof *cs->values);
+    for (size_t i = 0; i < n_values; i++) {
+        /* Use the lexer to convert each macro into the proper
+         * integer format. */
+        struct lexer lex;
+        lexer_init(&lex, values[i]);
+        lexer_get(&lex);
+        if (lex.token.type != LEX_T_INTEGER
+            && lex.token.type != LEX_T_MASKED_INTEGER) {
+            VLOG_WARN("Invalid address set entry: '%s', token type: %d",
+                      values[i], lex.token.type);
+        } else {
+            union expr_constant *c = &cs->values[cs->n_values++];
+            c->value = lex.token.value;
+            c->format = lex.token.format;
+            c->masked = lex.token.type == LEX_T_MASKED_INTEGER;
+            if (c->masked) {
+                c->mask = lex.token.mask;
+            }
+        }
+        lexer_destroy(&lex);
+    }
+
+    shash_add(macros, name, cs);
+}
+
+void
+expr_macros_remove(struct shash *macros, const char *name)
+{
+    struct expr_constant_set *cs = shash_find_and_delete(macros, name);
+    if (cs) {
+        expr_constant_set_destroy(cs);
+        free(cs);
+    }
+}
+
+/* Destroy all contents of 'macros'. */
+void
+expr_macros_destroy(struct shash *macros)
+{
+    struct shash_node *node, *next;
+
+    SHASH_FOR_EACH_SAFE (node, next, macros) {
+        struct expr_constant_set *cs = node->data;
+
+        shash_delete(macros, node);
+        expr_constant_set_destroy(cs);
+    }
+}
+
 static struct expr *
 expr_parse_primary(struct expr_context *ctx, bool *atomic)
 {
@@ -980,9 +1077,12 @@ expr_parse__(struct expr_context *ctx)
  * The caller must eventually free the returned expression (with
  * expr_destroy()) or error (with free()). */
 struct expr *
-expr_parse(struct lexer *lexer, const struct shash *symtab, char **errorp)
+expr_parse(struct lexer *lexer, const struct shash *symtab,
+           const struct shash *macros, char **errorp)
 {
-    struct expr_context ctx = { .lexer = lexer, .symtab = symtab };
+    struct expr_context ctx = { .lexer = lexer,
+                                .symtab = symtab,
+                                .macros = macros };
     struct expr *e = expr_parse__(&ctx);
     *errorp = ctx.error;
     ovs_assert((ctx.error != NULL) != (e != NULL));
@@ -991,14 +1091,15 @@ expr_parse(struct lexer *lexer, const struct shash *symtab, char **errorp)
 
 /* Like expr_parse(), but the expression is taken from 's'. */
 struct expr *
-expr_parse_string(const char *s, const struct shash *symtab, char **errorp)
+expr_parse_string(const char *s, const struct shash *symtab,
+                  const struct shash *macros, char **errorp)
 {
     struct lexer lexer;
     struct expr *expr;
 
     lexer_init(&lexer, s);
     lexer_get(&lexer);
-    expr = expr_parse(&lexer, symtab, errorp);
+    expr = expr_parse(&lexer, symtab, macros, errorp);
     if (!*errorp && lexer.token.type != LEX_T_END) {
         *errorp = xstrdup("Extra tokens at end of input.");
         expr_destroy(expr);
@@ -1149,7 +1250,7 @@ expr_get_level(const struct expr *expr)
 static enum expr_level
 expr_parse_level(const char *s, const struct shash *symtab, char **errorp)
 {
-    struct expr *expr = expr_parse_string(s, symtab, errorp);
+    struct expr *expr = expr_parse_string(s, symtab, NULL, errorp);
     enum expr_level level = expr ? expr_get_level(expr) : EXPR_L_NOMINAL;
     expr_destroy(expr);
     return level;
@@ -1292,7 +1393,7 @@ parse_and_annotate(const char *s, const struct shash *symtab,
     char *error;
     struct expr *expr;
 
-    expr = expr_parse_string(s, symtab, &error);
+    expr = expr_parse_string(s, symtab, NULL, &error);
     if (expr) {
         expr = expr_annotate__(expr, symtab, nesting, &error);
     }

diff --git a/ovn/lib/expr.h b/ovn/lib/expr.h
@@ -352,8 +352,10 @@ expr_from_node(const struct ovs_list *node)
 void expr_format(const struct expr *, struct ds *);
 void expr_print(const struct expr *);
 struct expr *expr_parse(struct lexer *, const struct shash *symtab,
+                        const struct shash *macros,
                         char **errorp);
 struct expr *expr_parse_string(const char *, const struct shash *symtab,
+                               const struct shash *macros,
                                char **errorp);
 
 struct expr *expr_clone(struct expr *);
@@ -453,4 +455,20 @@ char *expr_parse_constant_set(struct lexer *, const struct shash *symtab,
     OVS_WARN_UNUSED_RESULT;
 void expr_constant_set_destroy(struct expr_constant_set *cs);
 
+
+/* Address sets, aka "macros".
+ *
+ * Instead of referring to a set of value as:
+ *    {addr1, addr2, ..., addrN}
+ * You can register a set of values and refer to them as:
+ *    $name
+ * The macros should all have integer/masked-integer values.
+ * The values that don't qualify are ignored.
+ */
+
+void expr_macros_add(struct shash *macros, const char *name,
+                     const char * const *values, size_t n_values);
+void expr_macros_remove(struct shash *macros, const char *name);
+void expr_macros_destroy(struct shash *macros);
+
 #endif /* ovn/expr.h */
diff --git a/ovn/lib/lex.c b/ovn/lib/lex.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015 Nicira, Inc.
+ * Copyright (c) 2015, 2016 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -227,6 +227,10 @@ lex_token_format(const struct lex_token *token, struct ds *s)
         lex_token_format_masked_integer(token, s);
         break;
 
+    case LEX_T_MACRO:
+        ds_put_format(s, "$%s", token->s);
+        break;
+
     case LEX_T_LPAREN:
         ds_put_cstr(s, "(");
         break;
@@ -514,19 +518,31 @@ lex_is_idn(unsigned char c)
 }
 
 static const char *
-lex_parse_id(const char *p, struct lex_token *token)
+lex_parse_id(const char *p, enum lex_type type, struct lex_token *token)
 {
     const char *start = p;
 
     do {
         p++;
     } while (lex_is_idn(*p));
 
-    token->type = LEX_T_ID;
+    token->type = type;
     lex_token_strcpy(token, start, p - start);
     return p;
 }
 
+static const char *
+lex_parse_macro(const char *p, struct lex_token *token)
+{
+    p++;
+    if (!lex_is_id1(*p)) {
+        lex_error(token, "`$' must be followed by a valid identifier.");
+        return p;
+    }
+
+    return lex_parse_id(p, LEX_T_MACRO, token);
+}
+
 /* Initializes 'token' and parses the first token from the beginning of
  * null-terminated string 'p' into 'token'.  Stores a pointer to the start of
  * the token (after skipping white space and comments, if any) into '*startp'.
@@ -697,6 +713,10 @@ lex_token_parse(struct lex_token *token, const char *p, const char **startp)
         }
         break;
 
+    case '$':
+        p = lex_parse_macro(p, token);
+        break;
+
     case '0': case '1': case '2': case '3': case '4':
     case '5': case '6': case '7': case '8': case '9':
     case ':':
@@ -715,12 +735,12 @@ lex_token_parse(struct lex_token *token, const char *p, const char **startp)
          * digits followed by a colon, but identifiers never do. */
         p = (p[strspn(p, "0123456789abcdefABCDEF")] == ':'
              ? lex_parse_integer(p, token)
-             : lex_parse_id(p, token));
+             : lex_parse_id(p, LEX_T_ID, token));
         break;
 
     default:
         if (lex_is_id1(*p)) {
-            p = lex_parse_id(p, token);
+            p = lex_parse_id(p, LEX_T_ID, token);
         } else {
             if (isprint((unsigned char) *p)) {
                 lex_error(token, "Invalid character `%c' in input.", *p);

diff --git a/ovn/lib/lex.h b/ovn/lib/lex.h
@@ -36,6 +36,7 @@ enum lex_type {
     LEX_T_STRING,               /* "foo" */
     LEX_T_INTEGER,              /* 12345 or 1.2.3.4 or ::1 or 01:02:03:04:05 */
     LEX_T_MASKED_INTEGER,       /* 12345/10 or 1.2.0.0/16 or ::2/127 or... */
+    LEX_T_MACRO,                /* $NAME */
     LEX_T_ERROR,                /* invalid input */
 
     /* Bare tokens. */
@@ -77,20 +78,32 @@ enum lex_format {
 };
 const char *lex_format_to_string(enum lex_format);
 
-/* A token.
- *
- * 's' may point to 'buffer'; otherwise, it points to malloc()ed memory owned
- * by the token. */
+/* A token. */
 struct lex_token {
-    enum lex_type type;         /* One of LEX_*. */
-    char *s;                    /* LEX_T_ID, LEX_T_STRING, LEX_T_ERROR only. */
-    enum lex_format format;     /* LEX_T_INTEGER, LEX_T_MASKED_INTEGER only. */
+    /* One of LEX_*. */
+    enum lex_type type;
+
+    /* Meaningful for LEX_T_ID, LEX_T_STRING, LEX_T_ERROR, LEX_T_MACRO only.
+     * For these token types, 's' may point to 'buffer'; otherwise, it points
+     * to malloc()ed memory owned by the token.
+     *
+     * Must be NULL for other token types.
+     *
+     * For LEX_T_MACRO, 's' does not include the leading $. */
+    char *s;
+
+    /* LEX_T_INTEGER, LEX_T_MASKED_INTEGER only. */
+    enum lex_format format;
+
     union {
+        /* LEX_T_INTEGER, LEX_T_MASKED_INTEGER only. */
         struct {
             union mf_subvalue value; /* LEX_T_INTEGER, LEX_T_MASKED_INTEGER. */
             union mf_subvalue mask;  /* LEX_T_MASKED_INTEGER only. */
         };
-        char buffer[256];            /* Buffer for LEX_T_ID/LEX_T_STRING. */
+
+        /* LEX_T_ID, LEX_T_STRING, LEX_T_ERROR, LEX_T_MACRO only. */
+        char buffer[256];
     };
 };