@@ -167,6 +167,7 @@ struct nft_ctx *nft_ctx_new(uint32_t flags)
ctx->parser_max_errors = 10;
init_list_head(&ctx->cache.list);
ctx->flags = flags;
+ ctx->output.output_fp = stdout;
if (flags == NFT_CTX_DEFAULT)
nft_ctx_netlink_init(ctx);
@@ -190,6 +191,9 @@ FILE *nft_ctx_set_output(struct nft_ctx *ctx, FILE *fp)
{
FILE *old = ctx->output.output_fp;
+ if (!fp || ferror(fp))
+ return NULL;
+
ctx->output.output_fp = fp;
return old;
@@ -333,9 +337,6 @@ int nft_print(struct output_ctx *octx, const char *fmt, ...)
int ret;
va_list arg;
- if (!octx->output_fp)
- return -1;
-
va_start(arg, fmt);
ret = vfprintf(octx->output_fp, fmt, arg);
va_end(arg);
@@ -349,9 +350,6 @@ int nft_gmp_print(struct output_ctx *octx, const char *fmt, ...)
int ret;
va_list arg;
- if (!octx->output_fp)
- return -1;
-
va_start(arg, fmt);
ret = gmp_vfprintf(octx->output_fp, fmt, arg);
va_end(arg);
@@ -173,7 +173,6 @@ int main(int argc, char * const *argv)
int i, val, rc;
nft = nft_ctx_new(NFT_CTX_DEFAULT);
- nft_ctx_set_output(nft, stdout);
while (1) {
val = getopt_long(argc, argv, OPTSTRING, options, NULL);
@@ -1153,9 +1153,6 @@ static int do_command_export(struct netlink_ctx *ctx, struct cmd *cmd)
struct nftnl_ruleset *rs;
FILE *fp = ctx->octx->output_fp;
- if (!fp)
- return 0;
-
do {
rs = netlink_dump_ruleset(ctx, &cmd->handle, &cmd->location);
if (rs == NULL && errno != EINTR)
@@ -1163,8 +1160,7 @@ static int do_command_export(struct netlink_ctx *ctx, struct cmd *cmd)
} while (rs == NULL);
nftnl_ruleset_fprintf(fp, rs, cmd->export->format, 0);
- fprintf(fp, "\n");
- fflush(fp);
+ nft_print(ctx->octx, "\n");
nftnl_ruleset_free(rs);
return 0;
Initialize output_fp to 'stdout' upon context creation and check output stream validity in nft_ctx_set_output(). This allows to drop checks in nft_{gmp_,}print() and do_command_export(). While doing so for the latter, simplify it a bit by using nft_print() which takes care of flushing the output stream. If applications desire to drop all output, they are supposed to open /dev/null and assign that. Signed-off-by: Phil Sutter <phil@nwl.cc> --- src/libnftables.c | 10 ++++------ src/main.c | 1 - src/rule.c | 6 +----- 3 files changed, 5 insertions(+), 12 deletions(-)