[iptables PATCH v3 2/7] xtables-restore: Introduce struct nft_xt_restore_state

[Phil Sutter <phil@nwl.cc>]

This data structure holds parser state information. A follow-up patch
will extract line parsing code into a separate function which will need
a place to persistently store this info in between calls.

While being at it, make 'in_table' variable boolean and drop some extra
braces in conditionals checking its value.

Signed-off-by: Phil Sutter <phil@nwl.cc>
---
 iptables/xtables-restore.c | 66 ++++++++++++++++++++------------------
 1 file changed, 35 insertions(+), 31 deletions(-)

diff --git a/iptables/xtables-restore.c b/iptables/xtables-restore.c
index 341579bd8d1c3..a9cb4ea55ab8f 100644
--- a/iptables/xtables-restore.c
+++ b/iptables/xtables-restore.c
@@ -68,14 +68,18 @@ static const struct nft_xt_restore_cb restore_cb = {
 	.chain_restore  = nft_chain_restore,
 };
 
+struct nft_xt_restore_state {
+	const struct builtin_table *curtable;
+	struct argv_store av_store;
+	bool in_table;
+};
+
 void xtables_restore_parse(struct nft_handle *h,
 			   const struct nft_xt_restore_parse *p)
 {
-	const struct builtin_table *curtable = NULL;
 	const struct nft_xt_restore_cb *cb = p->cb;
-	struct argv_store av_store = {};
+	struct nft_xt_restore_state state = {};
 	char buffer[10240];
-	int in_table = 0;
 
 	line = 0;
 
@@ -97,7 +101,7 @@ void xtables_restore_parse(struct nft_handle *h,
 			if (verbose)
 				fputs(buffer, stdout);
 			continue;
-		} else if ((strcmp(buffer, "COMMIT\n") == 0) && (in_table)) {
+		} else if ((strcmp(buffer, "COMMIT\n") == 0) && state.in_table) {
 			if (!p->testing) {
 				/* Commit per table, although we support
 				 * global commit at once, stick by now to
@@ -111,9 +115,9 @@ void xtables_restore_parse(struct nft_handle *h,
 				if (cb->abort)
 					ret = cb->abort(h);
 			}
-			in_table = 0;
+			state.in_table = false;
 
-		} else if ((buffer[0] == '*') && (!in_table || !p->commit)) {
+		} else if ((buffer[0] == '*') && (!state.in_table || !p->commit)) {
 			/* New table */
 			char *table;
 
@@ -124,8 +128,8 @@ void xtables_restore_parse(struct nft_handle *h,
 					"%s: line %u table name invalid\n",
 					xt_params->program_name, line);
 
-			curtable = nft_table_builtin_find(h, table);
-			if (!curtable)
+			state.curtable = nft_table_builtin_find(h, table);
+			if (!state.curtable)
 				xtables_error(PARAMETER_PROBLEM,
 					"%s: line %u table name '%s' invalid\n",
 					xt_params->program_name, line, table);
@@ -141,12 +145,12 @@ void xtables_restore_parse(struct nft_handle *h,
 			}
 
 			ret = 1;
-			in_table = 1;
+			state.in_table = true;
 
 			if (cb->table_new)
 				cb->table_new(h, table);
 
-		} else if ((buffer[0] == ':') && (in_table)) {
+		} else if ((buffer[0] == ':') && state.in_table) {
 			/* New chain. */
 			char *policy, *chain = NULL;
 			struct xt_counters count = {};
@@ -171,7 +175,7 @@ void xtables_restore_parse(struct nft_handle *h,
 					   "%s: line %u policy invalid\n",
 					   xt_params->program_name, line);
 
-			if (nft_chain_builtin_find(curtable, chain)) {
+			if (nft_chain_builtin_find(state.curtable, chain)) {
 				if (counters) {
 					char *ctrs;
 					ctrs = strtok(NULL, " \t\n");
@@ -183,7 +187,7 @@ void xtables_restore_parse(struct nft_handle *h,
 
 				}
 				if (cb->chain_set &&
-				    cb->chain_set(h, curtable->name,
+				    cb->chain_set(h, state.curtable->name,
 					          chain, policy, &count) < 0) {
 					xtables_error(OTHER_PROBLEM,
 						      "Can't set policy `%s'"
@@ -193,14 +197,14 @@ void xtables_restore_parse(struct nft_handle *h,
 				}
 				DEBUGP("Setting policy of chain %s to %s\n",
 				       chain, policy);
-			} else if (cb->chain_restore(h, chain, curtable->name) < 0 &&
+			} else if (cb->chain_restore(h, chain, state.curtable->name) < 0 &&
 				   errno != EEXIST) {
 				xtables_error(PARAMETER_PROBLEM,
 					      "cannot create chain "
 					      "'%s' (%s)\n", chain,
 					      strerror(errno));
 			} else if (h->family == NFPROTO_BRIDGE &&
-				   !ebt_set_user_chain_policy(h, curtable->name,
+				   !ebt_set_user_chain_policy(h, state.curtable->name,
 							      chain, policy)) {
 				xtables_error(OTHER_PROBLEM,
 					      "Can't set policy `%s'"
@@ -209,30 +213,30 @@ void xtables_restore_parse(struct nft_handle *h,
 					      strerror(errno));
 			}
 			ret = 1;
-		} else if (in_table) {
+		} else if (state.in_table) {
 			char *pcnt = NULL;
 			char *bcnt = NULL;
 			char *parsestart = buffer;
 
-			add_argv(&av_store, xt_params->program_name, 0);
-			add_argv(&av_store, "-t", 0);
-			add_argv(&av_store, curtable->name, 0);
+			add_argv(&state.av_store, xt_params->program_name, 0);
+			add_argv(&state.av_store, "-t", 0);
+			add_argv(&state.av_store, state.curtable->name, 0);
 
 			tokenize_rule_counters(&parsestart, &pcnt, &bcnt, line);
 			if (counters && pcnt && bcnt) {
-				add_argv(&av_store, "--set-counters", 0);
-				add_argv(&av_store, pcnt, 0);
-				add_argv(&av_store, bcnt, 0);
+				add_argv(&state.av_store, "--set-counters", 0);
+				add_argv(&state.av_store, pcnt, 0);
+				add_argv(&state.av_store, bcnt, 0);
 			}
 
-			add_param_to_argv(&av_store, parsestart, line);
+			add_param_to_argv(&state.av_store, parsestart, line);
 
 			DEBUGP("calling do_command4(%u, argv, &%s, handle):\n",
-			       av_store.argc, curtable->name);
-			debug_print_argv(&av_store);
+			       state.av_store.argc, state.curtable->name);
+			debug_print_argv(&state.av_store);
 
-			ret = cb->do_command(h, av_store.argc, av_store.argv,
-					    &av_store.argv[2], true);
+			ret = cb->do_command(h, state.av_store.argc, state.av_store.argv,
+					    &state.av_store.argv[2], true);
 			if (ret < 0) {
 				if (cb->abort)
 					ret = cb->abort(h);
@@ -246,11 +250,11 @@ void xtables_restore_parse(struct nft_handle *h,
 				exit(1);
 			}
 
-			free_argv(&av_store);
+			free_argv(&state.av_store);
 			fflush(stdout);
 		}
-		if (p->tablename && curtable &&
-		    (strcmp(p->tablename, curtable->name) != 0))
+		if (p->tablename && state.curtable &&
+		    (strcmp(p->tablename, state.curtable->name) != 0))
 			continue;
 		if (!ret) {
 			fprintf(stderr, "%s: line %u failed\n",
@@ -258,11 +262,11 @@ void xtables_restore_parse(struct nft_handle *h,
 			exit(1);
 		}
 	}
-	if (in_table && p->commit) {
+	if (state.in_table && p->commit) {
 		fprintf(stderr, "%s: COMMIT expected at line %u\n",
 				xt_params->program_name, line + 1);
 		exit(1);
-	} else if (in_table && cb->commit && !cb->commit(h)) {
+	} else if (state.in_table && cb->commit && !cb->commit(h)) {
 		xtables_error(OTHER_PROBLEM, "%s: final implicit COMMIT failed",
 			      xt_params->program_name);
 	}
-- 
2.23.0