Re: libpcap: pcap_set_immediate_mode

[Jeremie Courreges-Anglas]

Lawrence Teo  writes:

> This imports pcap_set_immediate_mode() from mainline libpcap, which allows
> a libpcap-based program to process packets as soon as they arrive.
>
> ok?

Looks fine to me, ok jca@

-- 
jca | PGP : 0x1524E7EE / 5135 92C1 AD36 5293 2BDF  DDCC 0DFA 74AE 1524 E7EE

libpcap: pcap_set_immediate_mode

[Lawrence Teo]

This imports pcap_set_immediate_mode() from mainline libpcap, which allows
a libpcap-based program to process packets as soon as they arrive.

ok?

Index: pcap-bpf.c
===
RCS file: /cvs/src/lib/libpcap/pcap-bpf.c,v
retrieving revision 1.34
diff -u -p -r1.34 pcap-bpf.c
--- pcap-bpf.c  8 May 2016 08:20:50 -   1.34
+++ pcap-bpf.c  5 Oct 2016 02:33:50 -
@@ -565,6 +565,16 @@ pcap_activate(pcap_t *p)
}
}
 
+   if (p->opt.immediate) {
+   v = 1;
+   if (ioctl(p->fd, BIOCIMMEDIATE, ) < 0) {
+   snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
+   "BIOCIMMEDIATE: %s", pcap_strerror(errno));
+   status = PCAP_ERROR;
+   goto bad;
+   }
+   }
+
if (p->opt.promisc) {
/* set promiscuous mode, just warn if it fails */
if (ioctl(p->fd, BIOCPROMISC, NULL) < 0) {
@@ -846,6 +856,7 @@ pcap_create(const char *device, char *er
pcap_set_snaplen(p, 65535); /* max packet size */
p->opt.promisc = 0;
p->opt.buffer_size = 0;
+   p->opt.immediate = 0;
return (p);
 }
 
Index: pcap-int.h
===
RCS file: /cvs/src/lib/libpcap/pcap-int.h,v
retrieving revision 1.13
diff -u -p -r1.13 pcap-int.h
--- pcap-int.h  11 Apr 2014 04:08:58 -  1.13
+++ pcap-int.h  5 Oct 2016 02:34:37 -
@@ -48,6 +48,7 @@ struct pcap_opt {
char*source;
int promisc;
int rfmon;
+   int immediate;  /* immediate mode - deliver packets as soon as 
they arrive */
 };
 
 /*
Index: pcap.3
===
RCS file: /cvs/src/lib/libpcap/pcap.3,v
retrieving revision 1.45
diff -u -p -r1.45 pcap.3
--- pcap.3  6 Apr 2016 09:10:28 -   1.45
+++ pcap.3  5 Oct 2016 02:39:24 -
@@ -78,6 +78,7 @@
 .Nm pcap_set_rfmon ,
 .Nm pcap_set_timeout ,
 .Nm pcap_set_buffer_size ,
+.Nm pcap_set_immediate_mode ,
 .Nm pcap_activate ,
 .Nm pcap_statustostr ,
 .Nm pcap_offline_filter
@@ -195,6 +196,8 @@
 .Ft int
 .Fn pcap_set_buffer_size "pcap_t *p" "int buffer_size"
 .Ft int
+.Fn pcap_set_immediate_mode "pcap_t *p" "int immediate"
+.Ft int
 .Fn pcap_activate "pcap_t *p"
 .Ft const char *
 .Fn pcap_statustostr "int errnum"
@@ -613,6 +616,13 @@ sets the buffer size that will be used o
 handle is activated to
 .Fa buffer_size ,
 which is in units of bytes.
+.Pp
+.Fn pcap_set_immediate_mode
+sets whether immediate mode should be set on a capture handle when
+the handle is activated.
+If
+.Fa immediate
+is non-zero, immediate mode will be set, otherwise it will not be set.
 .Pp
 .Fn pcap_activate
 is used to activate a packet capture handle to look at
Index: pcap.c
===
RCS file: /cvs/src/lib/libpcap/pcap.c,v
retrieving revision 1.19
diff -u -p -r1.19 pcap.c
--- pcap.c  6 Apr 2016 08:02:56 -   1.19
+++ pcap.c  5 Oct 2016 02:24:57 -
@@ -223,6 +223,15 @@ pcap_set_timeout(pcap_t *p, int timeout_
 }
 
 int
+pcap_set_immediate_mode(pcap_t *p, int immediate)
+{
+   if (pcap_check_activated(p))
+   return PCAP_ERROR_ACTIVATED;
+   p->opt.immediate = immediate;
+   return 0;
+}
+
+int
 pcap_set_buffer_size(pcap_t *p, int buffer_size)
 {
if (pcap_check_activated(p))
Index: pcap.h
===
RCS file: /cvs/src/lib/libpcap/pcap.h,v
retrieving revision 1.18
diff -u -p -r1.18 pcap.h
--- pcap.h  6 Apr 2016 08:02:56 -   1.18
+++ pcap.h  5 Oct 2016 02:44:34 -
@@ -168,6 +168,7 @@ int pcap_set_promisc(pcap_t *, int);
 intpcap_can_set_rfmon(pcap_t *);
 intpcap_set_rfmon(pcap_t *, int);
 intpcap_set_timeout(pcap_t *, int);
+intpcap_set_immediate_mode(pcap_t *, int);
 intpcap_set_buffer_size(pcap_t *, int);
 intpcap_activate(pcap_t *);
 
Index: shlib_version
===
RCS file: /cvs/src/lib/libpcap/shlib_version,v
retrieving revision 1.15
diff -u -p -r1.15 shlib_version
--- shlib_version   6 Apr 2016 08:02:56 -   1.15
+++ shlib_version   5 Oct 2016 02:41:15 -
@@ -1,2 +1,2 @@
 major=8
-minor=1
+minor=2