diff options
| -rw-r--r-- | Documentation/networking/packet_mmap.txt | 18 | ||||
| -rw-r--r-- | include/uapi/linux/if_packet.h | 2 | ||||
| -rw-r--r-- | net/packet/af_packet.c | 12 |
3 files changed, 11 insertions, 21 deletions
diff --git a/Documentation/networking/packet_mmap.txt b/Documentation/networking/packet_mmap.txt index 38112d512f47..a6d7cb91069e 100644 --- a/Documentation/networking/packet_mmap.txt +++ b/Documentation/networking/packet_mmap.txt @@ -1008,14 +1008,9 @@ hardware timestamps to be used. Note: you may need to enable the generation of hardware timestamps with SIOCSHWTSTAMP (see related information from Documentation/networking/timestamping.txt). -PACKET_TIMESTAMP accepts the same integer bit field as -SO_TIMESTAMPING. However, only the SOF_TIMESTAMPING_SYS_HARDWARE -and SOF_TIMESTAMPING_RAW_HARDWARE values are recognized by -PACKET_TIMESTAMP. SOF_TIMESTAMPING_SYS_HARDWARE takes precedence over -SOF_TIMESTAMPING_RAW_HARDWARE if both bits are set. - - int req = 0; - req |= SOF_TIMESTAMPING_SYS_HARDWARE; +PACKET_TIMESTAMP accepts the same integer bit field as SO_TIMESTAMPING: + + int req = SOF_TIMESTAMPING_RAW_HARDWARE; setsockopt(fd, SOL_PACKET, PACKET_TIMESTAMP, (void *) &req, sizeof(req)) For the mmap(2)ed ring buffers, such timestamps are stored in the @@ -1023,14 +1018,13 @@ tpacket{,2,3}_hdr structure's tp_sec and tp_{n,u}sec members. To determine what kind of timestamp has been reported, the tp_status field is binary |'ed with the following possible bits ... - TP_STATUS_TS_SYS_HARDWARE TP_STATUS_TS_RAW_HARDWARE TP_STATUS_TS_SOFTWARE ... that are equivalent to its SOF_TIMESTAMPING_* counterparts. For the -RX_RING, if none of those 3 are set (i.e. PACKET_TIMESTAMP is not set), -then this means that a software fallback was invoked *within* PF_PACKET's -processing code (less precise). +RX_RING, if neither is set (i.e. PACKET_TIMESTAMP is not set), then a +software fallback was invoked *within* PF_PACKET's processing code (less +precise). Getting timestamps for the TX_RING works as follows: i) fill the ring frames, ii) call sendto() e.g. in blocking mode, iii) wait for status of relevant diff --git a/include/uapi/linux/if_packet.h b/include/uapi/linux/if_packet.h index bac27fa05f5b..da2d668b8cf1 100644 --- a/include/uapi/linux/if_packet.h +++ b/include/uapi/linux/if_packet.h @@ -108,7 +108,7 @@ struct tpacket_auxdata { /* Rx and Tx ring - header status */ #define TP_STATUS_TS_SOFTWARE (1 << 29) -#define TP_STATUS_TS_SYS_HARDWARE (1 << 30) +#define TP_STATUS_TS_SYS_HARDWARE (1 << 30) /* deprecated, never set */ #define TP_STATUS_TS_RAW_HARDWARE (1 << 31) /* Rx ring - feature request bits */ diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 614ca91f785a..8d9f8042705a 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -441,14 +441,10 @@ static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts, { struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); - if (shhwtstamps) { - if ((flags & SOF_TIMESTAMPING_SYS_HARDWARE) && - ktime_to_timespec_cond(shhwtstamps->syststamp, ts)) - return TP_STATUS_TS_SYS_HARDWARE; - if ((flags & SOF_TIMESTAMPING_RAW_HARDWARE) && - ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts)) - return TP_STATUS_TS_RAW_HARDWARE; - } + if (shhwtstamps && + (flags & SOF_TIMESTAMPING_RAW_HARDWARE) && + ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts)) + return TP_STATUS_TS_RAW_HARDWARE; if (ktime_to_timespec_cond(skb->tstamp, ts)) return TP_STATUS_TS_SOFTWARE; |