From 6c4fdcf71bfa653f58deda97b6d7e3c3cdd8f98c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jerry=20Lundstr=C3=B6m?= <lundstrom.jerry@gmail.com>
Date: Wed, 7 Aug 2019 13:11:40 +0200
Subject: [PATCH] libpcap

- `input.pcap`:
  - Issue #44: Add `create()` and `activate()`
  - Fix module name in usage documentation
---
 src/input/pcap.c   | 38 ++++++++++++++++++++++++++++++++++++++
 src/input/pcap.hh  |  2 ++
 src/input/pcap.lua | 17 ++++++++++++++++-
 3 files changed, 56 insertions(+), 1 deletion(-)

diff --git a/src/input/pcap.c b/src/input/pcap.c
index 80f93cb7..c3e937f2 100644
--- a/src/input/pcap.c
+++ b/src/input/pcap.c
@@ -55,6 +55,44 @@ void input_pcap_destroy(input_pcap_t* self)
     }
 }
 
+int input_pcap_create(input_pcap_t* self, const char* source)
+{
+    char errbuf[PCAP_ERRBUF_SIZE] = { 0 };
+    mlassert_self();
+    lassert(source, "source is nil");
+
+    if (self->pcap) {
+        lfatal("already opened");
+    }
+
+    if (!(self->pcap = pcap_create(source, errbuf))) {
+        lcritical("pcap_create(%s) error: %s", source, errbuf);
+        return -1;
+    }
+
+    self->snaplen    = pcap_snapshot(self->pcap);
+    self->linktype   = pcap_datalink(self->pcap);
+    self->is_swapped = 0;
+
+    self->prod_pkt.snaplen    = self->snaplen;
+    self->prod_pkt.linktype   = self->linktype;
+    self->prod_pkt.is_swapped = self->is_swapped;
+
+    ldebug("pcap v%u.%u snaplen:%lu %s", pcap_major_version(self->pcap), pcap_minor_version(self->pcap), self->snaplen, self->is_swapped ? " swapped" : "");
+
+    return 0;
+}
+
+int input_pcap_activate(input_pcap_t* self)
+{
+    mlassert_self();
+    if (!self->pcap) {
+        lfatal("no PCAP opened");
+    }
+
+    return pcap_activate(self->pcap);
+}
+
 int input_pcap_open_offline(input_pcap_t* self, const char* file)
 {
     char errbuf[PCAP_ERRBUF_SIZE] = { 0 };
diff --git a/src/input/pcap.hh b/src/input/pcap.hh
index da48741d..775ea189 100644
--- a/src/input/pcap.hh
+++ b/src/input/pcap.hh
@@ -47,6 +47,8 @@ core_log_t* input_pcap_log();
 
 void input_pcap_init(input_pcap_t* self);
 void input_pcap_destroy(input_pcap_t* self);
+int input_pcap_create(input_pcap_t* self, const char* source);
+int input_pcap_activate(input_pcap_t* self);
 int input_pcap_open_offline(input_pcap_t* self, const char* file);
 int input_pcap_loop(input_pcap_t* self, int cnt);
 int input_pcap_dispatch(input_pcap_t* self, int cnt);
diff --git a/src/input/pcap.lua b/src/input/pcap.lua
index 9958e98b..d884c0ae 100644
--- a/src/input/pcap.lua
+++ b/src/input/pcap.lua
@@ -18,7 +18,7 @@
 
 -- dnsjit.input.pcap
 -- Read input from an interface or PCAP file using libpcap
---   local input = require("dnsjit.input.pcapthread").new()
+--   local input = require("dnsjit.input.pcap").new()
 --   input:open_offline("file.pcap")
 --   input:receiver(filter_or_output)
 --   input:run()
@@ -64,6 +64,21 @@ function Pcap:produce()
     return C.input_pcap_producer(self.obj), self.obj
 end
 
+-- Open a live packet capture on
+-- .IR source ,
+-- which is an interface name or "any" (Linux) / "all" (BSD).
+-- Must be activated before use.
+function Pcap:create(source)
+    return C.input_pcap_create(self.obj, source)
+end
+
+-- Activate a live packet capture, see
+-- .BR pcap_activate (3pcap)
+-- for more information and possible return values.
+function Pcap:activate()
+    return C.input_pcap_activate(self.obj)
+end
+
 -- Open a PCAP file for processing.
 -- Returns 0 on success.
 function Pcap:open_offline(file)