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Add "settimestamp" and "gettimestamp" messages, providing the the ability

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to embed a timestamp (struct timeval) in outgoing packets.  The message
specifies the offset at which the timestamp should be inserted.

NG_SOURCE(4) gives an example usage that queues an ICMP packet.  Using that
example, the following command will insert a timestamp in the ICMP's data
payload:

  ngctl msg src0: settimestamp '{ offset=0x2a flags=1 }'

Sponsored by:	Sandvine Incorporated
This commit is contained in:
Ed Maste 2007-03-01 23:16:17 +00:00
parent b6f6e672f7
commit 5f87dd698c
2 changed files with 139 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

127
sys/netgraph/ng_source.c
View File

@ -77,6 +77,8 @@ __FBSDID("$FreeBSD$");
#define NG_SOURCE_INTR_TICKS 1
#define NG_SOURCE_DRIVER_IFQ_MAXLEN (4*1024)
#define mtod_off(m,off,t) ((t)(mtod((m),caddr_t)+(off)))
/* Per node info */
struct privdata {
node_p node;
@ -88,6 +90,7 @@ struct privdata {
struct callout intr_ch;
uint64_t packets; /* packets to send */
uint32_t queueOctets;
struct ng_source_embed_info embed_timestamp;
};
typedef struct privdata *sc_p;
@ -110,6 +113,10 @@ static int ng_source_start (sc_p, uint64_t);
static void ng_source_stop (sc_p);
static int ng_source_send (sc_p, int, int *);
static int ng_source_store_output_ifp(sc_p, char *);
static void ng_source_packet_mod(sc_p, struct mbuf *,
int, int, caddr_t, int);
static int ng_source_dup_mod(sc_p, struct mbuf *,
struct mbuf **);
/* Parse type for timeval */
static const struct ng_parse_struct_field ng_source_timeval_type_fields[] = {
@ -130,6 +137,14 @@ static const struct ng_parse_type ng_source_stats_type = {
&ng_source_stats_type_fields
};
/* Parse type for struct ng_source_embed_info */
static const struct ng_parse_struct_field ng_source_embed_type_fields[] =
NG_SOURCE_EMBED_TYPE_INFO;
static const struct ng_parse_type ng_source_embed_type = {
&ng_parse_struct_type,
&ng_source_embed_type_fields
};
/* List of commands and how to convert arguments to/from ASCII */
static const struct ng_cmdlist ng_source_cmds[] = {
{
@ -188,6 +203,20 @@ static const struct ng_cmdlist ng_source_cmds[] = {
&ng_parse_uint32_type,
NULL
},
{
NGM_SOURCE_COOKIE,
NGM_SOURCE_SET_TIMESTAMP,
"settimestamp",
&ng_source_embed_type,
NULL
},
{
NGM_SOURCE_COOKIE,
NGM_SOURCE_GET_TIMESTAMP,
"gettimestamp",
NULL,
&ng_source_embed_type
},
{ 0 }
};
@ -372,6 +401,29 @@ ng_source_rcvmsg(node_p node, item_p item, hook_p lasthook)
sc->stats.maxPps = pps;
break;
}
case NGM_SOURCE_SET_TIMESTAMP:
{
struct ng_source_embed_info *embed;
embed = (struct ng_source_embed_info *)msg->data;
bcopy(embed, &sc->embed_timestamp, sizeof(*embed));
break;
}
case NGM_SOURCE_GET_TIMESTAMP:
{
struct ng_source_embed_info *embed;
NG_MKRESPONSE(resp, msg, sizeof(*embed), M_DONTWAIT);
if (resp == NULL) {
error = ENOMEM;
goto done;
}
embed = (struct ng_source_embed_info *)resp->data;
bcopy(&sc->embed_timestamp, embed, sizeof(*embed));
break;
}
default:
@ -662,11 +714,13 @@ ng_source_send(sc_p sc, int tosend, int *sent_p)
if (m == NULL)
break;
/* Duplicate the packet. */
m2 = m_copypacket(m, M_DONTWAIT);
if (m2 == NULL) {
_IF_PREPEND(&sc->snd_queue, m);
error = ENOBUFS;
/* Duplicate and modify the packet. */
error = ng_source_dup_mod(sc, m, &m2);
if (error) {
if (error == ENOBUFS)
_IF_PREPEND(&sc->snd_queue, m);
else
_IF_ENQUEUE(&sc->snd_queue, m);
break;
}
@ -685,3 +739,66 @@ ng_source_send(sc_p sc, int tosend, int *sent_p)
*sent_p = sent;
return (error);
}
/*
* Modify packet in 'm' by changing 'len' bytes starting at 'offset'
* to data in 'cp'.
*
* The packet data in 'm' must be in a contiguous buffer in a single mbuf.
*/
static void
ng_source_packet_mod(sc_p sc, struct mbuf *m, int offset, int len, caddr_t cp,
int flags)
{
if (len == 0)
return;
/* Can't modify beyond end of packet. */
/* TODO: Pad packet for this case. */
if (offset + len > m->m_len)
return;
bcopy(cp, mtod_off(m, offset, caddr_t), len);
}
static int
ng_source_dup_mod(sc_p sc, struct mbuf *m0, struct mbuf **m_ptr)
{
struct mbuf *m;
struct ng_source_embed_info *ts;
int modify;
int error = 0;
/* Are we going to modify packets? */
modify = sc->embed_timestamp.flags & NGM_SOURCE_EMBED_ENABLE;
/* Duplicate the packet. */
if (modify)
m = m_dup(m0, M_DONTWAIT);
else
m = m_copypacket(m0, M_DONTWAIT);
if (m == NULL) {
error = ENOBUFS;
goto done;
}
*m_ptr = m;
if (!modify)
goto done;
/* Modify the copied packet for sending. */
KASSERT(M_WRITABLE(m), ("%s: packet not writable", __func__));
ts = &sc->embed_timestamp;
if (ts->flags & NGM_SOURCE_EMBED_ENABLE) {
struct timeval now;
getmicrotime(&now);
now.tv_sec = htonl(now.tv_sec);
now.tv_usec = htonl(now.tv_usec);
ng_source_packet_mod(sc, m, ts->offset, sizeof (now),
(caddr_t)&now, ts->flags);
}
done:
return(error);
}

17
sys/netgraph/ng_source.h
View File

@ -78,6 +78,21 @@ extern const struct ng_parse_type ng_source_timeval_type;
{ NULL } \
}
/* Packet embedding info for NGM_SOURCE_GET/SET_TIMESTAMP */
struct ng_source_embed_info {
uint16_t offset; /* offset from ethernet header */
uint8_t flags;
uint8_t spare;
};
#define NGM_SOURCE_EMBED_ENABLE 0x01 /* enable embedding */
/* Keep this in sync with the above structure definition. */
#define NG_SOURCE_EMBED_TYPE_INFO { \
{ "offset", &ng_parse_hint16_type }, \
{ "flags", &ng_parse_hint8_type }, \
{ NULL } \
}
/* Netgraph commands */
enum {
NGM_SOURCE_GET_STATS = 1, /* get stats */
@ -88,6 +103,8 @@ enum {
NGM_SOURCE_CLR_DATA, /* clear the queued data */
NGM_SOURCE_SETIFACE, /* configure downstream iface */
NGM_SOURCE_SETPPS, /* rate-limiting packets per second */
NGM_SOURCE_SET_TIMESTAMP, /* embed xmit timestamp */
NGM_SOURCE_GET_TIMESTAMP,
};
#endif /* _NETGRAPH_NG_SOURCE_H_ */