diff options
author | Phil Sutter <phil@nwl.cc> | 2017-11-20 16:54:04 +0100 |
---|---|---|
committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2017-11-22 13:18:34 +0100 |
commit | 1be5e6f808e3908ecd13ab68b3fea0739794f02d (patch) | |
tree | 1ea3cc4470d41229a04662536746fd6b95773753 /src | |
parent | f7828416525122914ccb2fa3b5bf2230fbce9c7d (diff) |
libnftables: Ensure output_fp is never NULL
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>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'src')
-rw-r--r-- | src/libnftables.c | 10 | ||||
-rw-r--r-- | src/main.c | 1 | ||||
-rw-r--r-- | src/rule.c | 6 |
3 files changed, 5 insertions, 12 deletions
diff --git a/src/libnftables.c b/src/libnftables.c index e8fa6742..c86d8947 100644 --- a/src/libnftables.c +++ b/src/libnftables.c @@ -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; |