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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-09 13:08:37 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-09 13:08:37 +0000
commit971e619d8602fa52b1bfcb3ea65b7ab96be85318 (patch)
tree26feb2498c72b796e07b86349d17f544046de279 /src/nftutils.c
parentInitial commit. (diff)
downloadnftables-971e619d8602fa52b1bfcb3ea65b7ab96be85318.tar.xz
nftables-971e619d8602fa52b1bfcb3ea65b7ab96be85318.zip
Adding upstream version 1.0.9.upstream/1.0.9upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/nftutils.c')
-rw-r--r--src/nftutils.c100
1 files changed, 100 insertions, 0 deletions
diff --git a/src/nftutils.c b/src/nftutils.c
new file mode 100644
index 0000000..ca178aa
--- /dev/null
+++ b/src/nftutils.c
@@ -0,0 +1,100 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include <nft.h>
+
+#include "nftutils.h"
+
+#include <netdb.h>
+
+/* Buffer size used for getprotobynumber_r() and similar. The manual comments
+ * that a buffer of 1024 should be sufficient "for most applications"(??), so
+ * let's double it. It still fits reasonably on the stack, so no need to
+ * choose a smaller one. */
+#define NETDB_BUFSIZE 2048
+
+bool nft_getprotobynumber(int proto, char *out_name, size_t name_len)
+{
+ const struct protoent *result;
+
+#if HAVE_DECL_GETPROTOBYNUMBER_R
+ struct protoent result_buf;
+ char buf[NETDB_BUFSIZE];
+ int r;
+
+ r = getprotobynumber_r(proto,
+ &result_buf,
+ buf,
+ sizeof(buf),
+ (struct protoent **) &result);
+ if (r != 0 || result != &result_buf)
+ result = NULL;
+#else
+ result = getprotobynumber(proto);
+#endif
+
+ if (!result)
+ return false;
+
+ if (strlen(result->p_name) >= name_len)
+ return false;
+ strcpy(out_name, result->p_name);
+ return true;
+}
+
+int nft_getprotobyname(const char *name)
+{
+ const struct protoent *result;
+
+#if HAVE_DECL_GETPROTOBYNAME_R
+ struct protoent result_buf;
+ char buf[NETDB_BUFSIZE];
+ int r;
+
+ r = getprotobyname_r(name,
+ &result_buf,
+ buf,
+ sizeof(buf),
+ (struct protoent **) &result);
+ if (r != 0 || result != &result_buf)
+ result = NULL;
+#else
+ result = getprotobyname(name);
+#endif
+
+ if (!result)
+ return -1;
+
+ if (result->p_proto < 0 || result->p_proto > UINT8_MAX)
+ return -1;
+ return (uint8_t) result->p_proto;
+}
+
+bool nft_getservbyport(int port, const char *proto, char *out_name, size_t name_len)
+{
+ const struct servent *result;
+
+#if HAVE_DECL_GETSERVBYPORT_R
+ struct servent result_buf;
+ char buf[NETDB_BUFSIZE];
+ int r;
+
+ r = getservbyport_r(port,
+ proto,
+ &result_buf,
+ buf,
+ sizeof(buf),
+ (struct servent**) &result);
+ if (r != 0 || result != &result_buf)
+ result = NULL;
+#else
+ result = getservbyport(port, proto);
+#endif
+
+ if (!result)
+ return false;
+
+ if (strlen(result->s_name) >= name_len)
+ return false;
+ strcpy(out_name, result->s_name);
+ return true;
+}