ovn-controller: Add 'put_dhcp_opts' action in ovn-controller

This patch adds a new OVN action 'put_dhcp_opts' to support native
DHCP in OVN.

ovn-controller parses this action and adds a NXT_PACKET_IN2
OF flow with 'pause' flag set and the DHCP options stored in
'userdata' field.

When the valid DHCP packet is received by ovn-controller, it frames a
new DHCP reply packet with the DHCP options present in the
'userdata' field and resumes the packet and stores 1 in the 1-bit subfield.
If the packet is invalid, it resumes the packet without any modifying and
stores 0 in the 1-bit subfield.

Eg. reg0[0] = put_dhcp_opts(offerip = 10.0.0.4, router = 10.0.0.1,
                  netmask = 255.255.255.0, lease_time = 3600,....)

A new 'DHCP_Options' table is added in SB DB which stores
the supported DHCP options with DHCP code and type. ovn-northd is
expected to popule this table.

The next patch will add logical flows with this action.

Signed-off-by: Numan Siddique <nusiddiq@redhat.com>
Co-authored-by: Ben Pfaff <blp@ovn.org>
Signed-off-by: Ben Pfaff <blp@ovn.org>

1 files changed, 10 insertions, 35 deletions

diff --git a/ovn/lib/expr.c b/ovn/lib/expr.c
index 31b94d81c..91bff075d 100644
--- a/ovn/lib/expr.c
+++ b/ovn/lib/expr.c
@@ -405,39 +405,6 @@ expr_print(const struct expr *e)
 
 /* Parsing. */
 
-/* Type of a "union expr_constant" or "struct expr_constant_set". */
-enum expr_constant_type {
-    EXPR_C_INTEGER,
-    EXPR_C_STRING
-};
-
-/* A string or integer constant (one must know which from context). */
-union expr_constant {
-    /* Integer constant.
-     *
-     * The width of a constant isn't always clear, e.g. if you write "1",
-     * there's no way to tell whether you mean for that to be a 1-bit constant
-     * or a 128-bit constant or somewhere in between. */
-    struct {
-        union mf_subvalue value;
-        union mf_subvalue mask; /* Only initialized if 'masked'. */
-        bool masked;
-
-        enum lex_format format; /* From the constant's lex_token. */
-    };
-
-    /* Null-terminated string constant. */
-    char *string;
-};
-
-/* A collection of "union expr_constant"s of the same type. */
-struct expr_constant_set {
-    union expr_constant *values;  /* Constants. */
-    size_t n_values;              /* Number of constants. */
-    enum expr_constant_type type; /* Type of the constants. */
-    bool in_curlies;              /* Whether the constants were in {}. */
-};
-
 /* Context maintained during expr_parse(). */
 struct expr_context {
     struct lexer *lexer;        /* Lexer for pulling more tokens. */
@@ -448,7 +415,6 @@ struct expr_context {
 
 struct expr *expr_parse__(struct expr_context *);
 static void expr_not(struct expr *);
-static void expr_constant_set_destroy(struct expr_constant_set *);
 static bool parse_field(struct expr_context *, struct expr_field *);
 
 static bool
@@ -829,7 +795,7 @@ parse_constant_set(struct expr_context *ctx, struct expr_constant_set *cs)
     return ok;
 }
 
-static void
+void
 expr_constant_set_destroy(struct expr_constant_set *cs)
 {
     if (cs) {
@@ -2931,3 +2897,12 @@ exit:
     }
     return ctx.error;
 }
+
+char * OVS_WARN_UNUSED_RESULT
+expr_parse_constant_set(struct lexer *lexer, const struct shash *symtab,
+                        struct expr_constant_set *cs)
+{
+    struct expr_context ctx = { .lexer = lexer, .symtab = symtab };
+    parse_constant_set(&ctx, cs);
+    return ctx.error;
+}