This patch introduces SO_TXTIME. User space enables this option in order to pass a desired future transmit time in a CMSG when calling sendmsg(2). The argument to this socket option is a 8-bytes long struct provided by the uapi header net_tstamp.h defined as: struct sock_txtime { clockid_t clockid; u32 flags; }; Note that new fields were added to struct sock by filling a 2-bytes hole found in the struct. For that reason, neither the struct size or number of cachelines were altered.
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| @@ -107,4 +107,7 @@ · 106 unmodified lines | |||
| 107 | 107 | ||
| 108 | #define SO_ZEROCOPY 60 | 108 | #define SO_ZEROCOPY 60 |
| 109 | 109 | ||
| 110 | #define SO_TXTIME 61 | ||
| 111 | #define SCM_TXTIME SO_TXTIME | ||
| 112 | |||
| 110 | #endif /* __ASM_GENERIC_SOCKET_H */ | 113 | #endif /* __ASM_GENERIC_SOCKET_H */ |
| @@ -141,4 +141,19 @@ struct scm_ts_pktinfo { · 140 unmodified lines | |||
| 141 | __u32 reserved[2]; | 141 | __u32 reserved[2]; |
| 142 | }; | 142 | }; |
| 143 | 143 | ||
| 144 | /* | ||
| 145 | * SO_TXTIME gets a struct sock_txtime with flags being an integer bit | ||
| 146 | * field comprised of these values. | ||
| 147 | */ | ||
| 148 | enum txtime_flags { | ||
| 149 | SOF_TXTIME_DEADLINE_MODE = (1 << 0), | ||
| 150 | |||
| 151 | SOF_TXTIME_FLAGS_MASK = (SOF_TXTIME_DEADLINE_MODE) | ||
| 152 | }; | ||
| 153 | |||
| 154 | struct sock_txtime { | ||
| 155 | clockid_t clockid; /* reference clockid */ | ||
| 156 | u32 flags; /* flags defined by enum txtime_flags */ | ||
| 157 | }; | ||
| 158 | |||
| 144 | #endif /* _NET_TIMESTAMPING_H */ | 159 | #endif /* _NET_TIMESTAMPING_H */ |