diff options
Diffstat (limited to 'Documentation/networking')
| -rw-r--r-- | Documentation/networking/dctcp.txt | 43 | ||||
| -rw-r--r-- | Documentation/networking/filter.txt | 271 | ||||
| -rw-r--r-- | Documentation/networking/ip-sysctl.txt | 40 | ||||
| -rw-r--r-- | Documentation/networking/pktgen.txt | 3 | ||||
| -rw-r--r-- | Documentation/networking/timestamping.txt | 368 | ||||
| -rw-r--r-- | Documentation/networking/timestamping/Makefile | 8 | ||||
| -rw-r--r-- | Documentation/networking/timestamping/txtimestamp.c | 469 |
7 files changed, 1110 insertions, 92 deletions
diff --git a/Documentation/networking/dctcp.txt b/Documentation/networking/dctcp.txt new file mode 100644 index 000000000000..0d5dfbc89ec9 --- /dev/null +++ b/Documentation/networking/dctcp.txt @@ -0,0 +1,43 @@ +DCTCP (DataCenter TCP) +---------------------- + +DCTCP is an enhancement to the TCP congestion control algorithm for data +center networks and leverages Explicit Congestion Notification (ECN) in +the data center network to provide multi-bit feedback to the end hosts. + +To enable it on end hosts: + + sysctl -w net.ipv4.tcp_congestion_control=dctcp + +All switches in the data center network running DCTCP must support ECN +marking and be configured for marking when reaching defined switch buffer +thresholds. The default ECN marking threshold heuristic for DCTCP on +switches is 20 packets (30KB) at 1Gbps, and 65 packets (~100KB) at 10Gbps, +but might need further careful tweaking. + +For more details, see below documents: + +Paper: + +The algorithm is further described in detail in the following two +SIGCOMM/SIGMETRICS papers: + + i) Mohammad Alizadeh, Albert Greenberg, David A. Maltz, Jitendra Padhye, + Parveen Patel, Balaji Prabhakar, Sudipta Sengupta, and Murari Sridharan: + "Data Center TCP (DCTCP)", Data Center Networks session + Proc. ACM SIGCOMM, New Delhi, 2010. + http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp-final.pdf + http://www.sigcomm.org/ccr/papers/2010/October/1851275.1851192 + +ii) Mohammad Alizadeh, Adel Javanmard, and Balaji Prabhakar: + "Analysis of DCTCP: Stability, Convergence, and Fairness" + Proc. ACM SIGMETRICS, San Jose, 2011. + http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp_analysis-full.pdf + +IETF informational draft: + + http://tools.ietf.org/html/draft-bensley-tcpm-dctcp-00 + +DCTCP site: + + http://simula.stanford.edu/~alizade/Site/DCTCP.html diff --git a/Documentation/networking/filter.txt b/Documentation/networking/filter.txt index f4db0972ea38..b1935f9ce081 100644 --- a/Documentation/networking/filter.txt +++ b/Documentation/networking/filter.txt @@ -951,7 +951,7 @@ Size modifier is one of ... Mode modifier is one of: - BPF_IMM 0x00 /* classic BPF only, reserved in eBPF */ + BPF_IMM 0x00 /* used for 32-bit mov in classic BPF and 64-bit in eBPF */ BPF_ABS 0x20 BPF_IND 0x40 BPF_MEM 0x60 @@ -995,6 +995,275 @@ BPF_XADD | BPF_DW | BPF_STX: lock xadd *(u64 *)(dst_reg + off16) += src_reg Where size is one of: BPF_B or BPF_H or BPF_W or BPF_DW. Note that 1 and 2 byte atomic increments are not supported. +eBPF has one 16-byte instruction: BPF_LD | BPF_DW | BPF_IMM which consists +of two consecutive 'struct bpf_insn' 8-byte blocks and interpreted as single +instruction that loads 64-bit immediate value into a dst_reg. +Classic BPF has similar instruction: BPF_LD | BPF_W | BPF_IMM which loads +32-bit immediate value into a register. + +eBPF verifier +------------- +The safety of the eBPF program is determined in two steps. + +First step does DAG check to disallow loops and other CFG validation. +In particular it will detect programs that have unreachable instructions. +(though classic BPF checker allows them) + +Second step starts from the first insn and descends all possible paths. +It simulates execution of every insn and observes the state change of +registers and stack. + +At the start of the program the register R1 contains a pointer to context +and has type PTR_TO_CTX. +If verifier sees an insn that does R2=R1, then R2 has now type +PTR_TO_CTX as well and can be used on the right hand side of expression. +If R1=PTR_TO_CTX and insn is R2=R1+R1, then R2=UNKNOWN_VALUE, +since addition of two valid pointers makes invalid pointer. +(In 'secure' mode verifier will reject any type of pointer arithmetic to make +sure that kernel addresses don't leak to unprivileged users) + +If register was never written to, it's not readable: + bpf_mov R0 = R2 + bpf_exit +will be rejected, since R2 is unreadable at the start of the program. + +After kernel function call, R1-R5 are reset to unreadable and +R0 has a return type of the function. + +Since R6-R9 are callee saved, their state is preserved across the call. + bpf_mov R6 = 1 + bpf_call foo + bpf_mov R0 = R6 + bpf_exit +is a correct program. If there was R1 instead of R6, it would have +been rejected. + +load/store instructions are allowed only with registers of valid types, which +are PTR_TO_CTX, PTR_TO_MAP, FRAME_PTR. They are bounds and alignment checked. +For example: + bpf_mov R1 = 1 + bpf_mov R2 = 2 + bpf_xadd *(u32 *)(R1 + 3) += R2 + bpf_exit +will be rejected, since R1 doesn't have a valid pointer type at the time of +execution of instruction bpf_xadd. + +At the start R1 type is PTR_TO_CTX (a pointer to generic 'struct bpf_context') +A callback is used to customize verifier to restrict eBPF program access to only +certain fields within ctx structure with specified size and alignment. + +For example, the following insn: + bpf_ld R0 = *(u32 *)(R6 + 8) +intends to load a word from address R6 + 8 and store it into R0 +If R6=PTR_TO_CTX, via is_valid_access() callback the verifier will know +that offset 8 of size 4 bytes can be accessed for reading, otherwise +the verifier will reject the program. +If R6=FRAME_PTR, then access should be aligned and be within +stack bounds, which are [-MAX_BPF_STACK, 0). In this example offset is 8, +so it will fail verification, since it's out of bounds. + +The verifier will allow eBPF program to read data from stack only after +it wrote into it. +Classic BPF verifier does similar check with M[0-15] memory slots. +For example: + bpf_ld R0 = *(u32 *)(R10 - 4) + bpf_exit +is invalid program. +Though R10 is correct read-only register and has type FRAME_PTR +and R10 - 4 is within stack bounds, there were no stores into that location. + +Pointer register spill/fill is tracked as well, since four (R6-R9) +callee saved registers may not be enough for some programs. + +Allowed function calls are customized with bpf_verifier_ops->get_func_proto() +The eBPF verifier will check that registers match argument constraints. +After the call register R0 will be set to return type of the function. + +Function calls is a main mechanism to extend functionality of eBPF programs. +Socket filters may let programs to call one set of functions, whereas tracing +filters may allow completely different set. + +If a function made accessible to eBPF program, it needs to be thought through +from safety point of view. The verifier will guarantee that the function is +called with valid arguments. + +seccomp vs socket filters have different security restrictions for classic BPF. +Seccomp solves this by two stage verifier: classic BPF verifier is followed +by seccomp verifier. In case of eBPF one configurable verifier is shared for +all use cases. + +See details of eBPF verifier in kernel/bpf/verifier.c + +eBPF maps +--------- +'maps' is a generic storage of different types for sharing data between kernel +and userspace. + +The maps are accessed from user space via BPF syscall, which has commands: +- create a map with given type and attributes + map_fd = bpf(BPF_MAP_CREATE, union bpf_attr *attr, u32 size) + using attr->map_type, attr->key_size, attr->value_size, attr->max_entries + returns process-local file descriptor or negative error + +- lookup key in a given map + err = bpf(BPF_MAP_LOOKUP_ELEM, union bpf_attr *attr, u32 size) + using attr->map_fd, attr->key, attr->value + returns zero and stores found elem into value or negative error + +- create or update key/value pair in a given map + err = bpf(BPF_MAP_UPDATE_ELEM, union bpf_attr *attr, u32 size) + using attr->map_fd, attr->key, attr->value + returns zero or negative error + +- find and delete element by key in a given map + err = bpf(BPF_MAP_DELETE_ELEM, union bpf_attr *attr, u32 size) + using attr->map_fd, attr->key + +- to delete map: close(fd) + Exiting process will delete maps automatically + +userspace programs use this syscall to create/access maps that eBPF programs +are concurrently updating. + +maps can have different types: hash, array, bloom filter, radix-tree, etc. + +The map is defined by: + . type + . max number of elements + . key size in bytes + . value size in bytes + +Understanding eBPF verifier messages +------------------------------------ + +The following are few examples of invalid eBPF programs and verifier error +messages as seen in the log: + +Program with unreachable instructions: +static struct bpf_insn prog[] = { + BPF_EXIT_INSN(), + BPF_EXIT_INSN(), +}; +Error: + unreachable insn 1 + +Program that reads uninitialized register: + BPF_MOV64_REG(BPF_REG_0, BPF_REG_2), + BPF_EXIT_INSN(), +Error: + 0: (bf) r0 = r2 + R2 !read_ok + +Program that doesn't initialize R0 before exiting: + BPF_MOV64_REG(BPF_REG_2, BPF_REG_1), + BPF_EXIT_INSN(), +Error: + 0: (bf) r2 = r1 + 1: (95) exit + R0 !read_ok + +Program that accesses stack out of bounds: + BPF_ST_MEM(BPF_DW, BPF_REG_10, 8, 0), + BPF_EXIT_INSN(), +Error: + 0: (7a) *(u64 *)(r10 +8) = 0 + invalid stack off=8 size=8 + +Program that doesn't initialize stack before passing its address into function: + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem), + BPF_EXIT_INSN(), +Error: + 0: (bf) r2 = r10 + 1: (07) r2 += -8 + 2: (b7) r1 = 0x0 + 3: (85) call 1 + invalid indirect read from stack off -8+0 size 8 + +Program that uses invalid map_fd=0 while calling to map_lookup_elem() function: + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem), + BPF_EXIT_INSN(), +Error: + 0: (7a) *(u64 *)(r10 -8) = 0 + 1: (bf) r2 = r10 + 2: (07) r2 += -8 + 3: (b7) r1 = 0x0 + 4: (85) call 1 + fd 0 is not pointing to valid bpf_map + +Program that doesn't check return value of map_lookup_elem() before accessing +map element: + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem), + BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, 0), + BPF_EXIT_INSN(), +Error: + 0: (7a) *(u64 *)(r10 -8) = 0 + 1: (bf) r2 = r10 + 2: (07) r2 += -8 + 3: (b7) r1 = 0x0 + 4: (85) call 1 + 5: (7a) *(u64 *)(r0 +0) = 0 + R0 invalid mem access 'map_value_or_null' + +Program that correctly checks map_lookup_elem() returned value for NULL, but +accesses the memory with incorrect alignment: + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1), + BPF_ST_MEM(BPF_DW, BPF_REG_0, 4, 0), + BPF_EXIT_INSN(), +Error: + 0: (7a) *(u64 *)(r10 -8) = 0 + 1: (bf) r2 = r10 + 2: (07) r2 += -8 + 3: (b7) r1 = 1 + 4: (85) call 1 + 5: (15) if r0 == 0x0 goto pc+1 + R0=map_ptr R10=fp + 6: (7a) *(u64 *)(r0 +4) = 0 + misaligned access off 4 size 8 + +Program that correctly checks map_lookup_elem() returned value for NULL and +accesses memory with correct alignment in one side of 'if' branch, but fails +to do so in the other side of 'if' branch: + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), + BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, 0), + BPF_EXIT_INSN(), + BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, 1), + BPF_EXIT_INSN(), +Error: + 0: (7a) *(u64 *)(r10 -8) = 0 + 1: (bf) r2 = r10 + 2: (07) r2 += -8 + 3: (b7) r1 = 1 + 4: (85) call 1 + 5: (15) if r0 == 0x0 goto pc+2 + R0=map_ptr R10=fp + 6: (7a) *(u64 *)(r0 +0) = 0 + 7: (95) exit + + from 5 to 8: R0=imm0 R10=fp + 8: (7a) *(u64 *)(r0 +0) = 1 + R0 invalid mem access 'imm' + Testing ------- diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index caedb18d4564..0307e2875f21 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -65,6 +65,12 @@ neigh/default/gc_thresh1 - INTEGER purge entries if there are fewer than this number. Default: 128 +neigh/default/gc_thresh2 - INTEGER + Threshold when garbage collector becomes more aggressive about + purging entries. Entries older than 5 seconds will be cleared + when over this number. + Default: 512 + neigh/default/gc_thresh3 - INTEGER Maximum number of neighbor entries allowed. Increase this when using large numbers of interfaces and when communicating @@ -757,8 +763,21 @@ icmp_ratelimit - INTEGER icmp_ratemask (see below) to specific targets. 0 to disable any limiting, otherwise the minimal space between responses in milliseconds. + Note that another sysctl, icmp_msgs_per_sec limits the number + of ICMP packets sent on all targets. + Default: 1000 + +icmp_msgs_per_sec - INTEGER + Limit maximal number of ICMP packets sent per second from this host. + Only messages whose type matches icmp_ratemask (see below) are + controlled by this limit. Default: 1000 +icmp_msgs_burst - INTEGER + icmp_msgs_per_sec controls number of ICMP packets sent per second, + while icmp_msgs_burst controls the burst size of these packets. + Default: 50 + icmp_ratemask - INTEGER Mask made of ICMP types for which rates are being limited. Significant bits: IHGFEDCBA9876543210 @@ -832,6 +851,11 @@ igmp_max_memberships - INTEGER conf/all/* is special, changes the settings for all interfaces +igmp_qrv - INTEGER + Controls the IGMP query robustness variable (see RFC2236 8.1). + Default: 2 (as specified by RFC2236 8.1) + Minimum: 1 (as specified by RFC6636 4.5) + log_martians - BOOLEAN Log packets with impossible addresses to kernel log. log_martians for the interface will be enabled if at least one of @@ -935,14 +959,9 @@ accept_source_route - BOOLEAN FALSE (host) accept_local - BOOLEAN - Accept packets with local source addresses. In combination - with suitable routing, this can be used to direct packets - between two local interfaces over the wire and have them - accepted properly. - - rp_filter must be set to a non-zero value in order for - accept_local to have an effect. - + Accept packets with local source addresses. In combination with + suitable routing, this can be used to direct packets between two + local interfaces over the wire and have them accepted properly. default FALSE route_localnet - BOOLEAN @@ -1140,6 +1159,11 @@ anycast_src_echo_reply - BOOLEAN FALSE: disabled Default: FALSE +mld_qrv - INTEGER + Controls the MLD query robustness variable (see RFC3810 9.1). + Default: 2 (as specified by RFC3810 9.1) + Minimum: 1 (as specified by RFC6636 4.5) + IPv6 Fragmentation: ip6frag_high_thresh - INTEGER diff --git a/Documentation/networking/pktgen.txt b/Documentation/networking/pktgen.txt index 0dffc6e37902..6915c6b27869 100644 --- a/Documentation/networking/pktgen.txt +++ b/Documentation/networking/pktgen.txt @@ -99,6 +99,9 @@ Examples: pgset "clone_skb 1" sets the number of copies of the same packet pgset "clone_skb 0" use single SKB for all transmits + pgset "burst 8" uses xmit_more API to queue 8 copies of the same + packet and update HW tx queue tail pointer once. + "burst 1" is the default pgset "pkt_size 9014" sets packet size to 9014 pgset "frags 5" packet will consist of 5 fragments pgset "count 200000" sets number of packets to send, set to zero diff --git a/Documentation/networking/timestamping.txt b/Documentation/networking/timestamping.txt index 897f942b976b..412f45ca2d73 100644 --- a/Documentation/networking/timestamping.txt +++ b/Documentation/networking/timestamping.txt @@ -1,102 +1,307 @@ -The existing interfaces for getting network packages time stamped are: + +1. Control Interfaces + +The interfaces for receiving network packages timestamps are: * SO_TIMESTAMP - Generate time stamp for each incoming packet using the (not necessarily - monotonous!) system time. Result is returned via recv_msg() in a - control message as timeval (usec resolution). + Generates a timestamp for each incoming packet in (not necessarily + monotonic) system time. Reports the timestamp via recvmsg() in a + control message as struct timeval (usec resolution). * SO_TIMESTAMPNS - Same time stamping mechanism as SO_TIMESTAMP, but returns result as - timespec (nsec resolution). + Same timestamping mechanism as SO_TIMESTAMP, but reports the + timestamp as struct timespec (nsec resolution). * IP_MULTICAST_LOOP + SO_TIMESTAMP[NS] - Only for multicasts: approximate send time stamp by receiving the looped - packet and using its receive time stamp. + Only for multicast:approximate transmit timestamp obtained by + reading the looped packet receive timestamp. -The following interface complements the existing ones: receive time -stamps can be generated and returned for arbitrary packets and much -closer to the point where the packet is really sent. Time stamps can -be generated in software (as before) or in hardware (if the hardware -has such a feature). +* SO_TIMESTAMPING + Generates timestamps on reception, transmission or both. Supports + multiple timestamp sources, including hardware. Supports generating + timestamps for stream sockets. -SO_TIMESTAMPING: -Instructs the socket layer which kind of information should be collected -and/or reported. The parameter is an integer with some of the following -bits set. Setting other bits is an error and doesn't change the current -state. +1.1 SO_TIMESTAMP: -Four of the bits are requests to the stack to try to generate -timestamps. Any combination of them is valid. +This socket option enables timestamping of datagrams on the reception +path. Because the destination socket, if any, is not known early in +the network stack, the feature has to be enabled for all packets. The +same is true for all early receive timestamp options. -SOF_TIMESTAMPING_TX_HARDWARE: try to obtain send time stamps in hardware -SOF_TIMESTAMPING_TX_SOFTWARE: try to obtain send time stamps in software -SOF_TIMESTAMPING_RX_HARDWARE: try to obtain receive time stamps in hardware -SOF_TIMESTAMPING_RX_SOFTWARE: try to obtain receive time stamps in software +For interface details, see `man 7 socket`. + + +1.2 SO_TIMESTAMPNS: + +This option is identical to SO_TIMESTAMP except for the returned data type. +Its struct timespec allows for higher resolution (ns) timestamps than the +timeval of SO_TIMESTAMP (ms). + + +1.3 SO_TIMESTAMPING: + +Supports multiple types of timestamp requests. As a result, this +socket option takes a bitmap of flags, not a boolean. In + + err = setsockopt(fd, SOL_SOCKET, SO_TIMESTAMPING, (void *) val, &val); + +val is an integer with any of the following bits set. Setting other +bit returns EINVAL and does not change the current state. -The other three bits control which timestamps will be reported in a -generated control message. If none of these bits are set or if none of -the set bits correspond to data that is available, then the control -message will not be generated: -SOF_TIMESTAMPING_SOFTWARE: report systime if available -SOF_TIMESTAMPING_SYS_HARDWARE: report hwtimetrans if available (deprecated) -SOF_TIMESTAMPING_RAW_HARDWARE: report hwtimeraw if available +1.3.1 Timestamp Generation -It is worth noting that timestamps may be collected for reasons other -than being requested by a particular socket with -SOF_TIMESTAMPING_[TR]X_(HARD|SOFT)WARE. For example, most drivers that -can generate hardware receive timestamps ignore -SOF_TIMESTAMPING_RX_HARDWARE. It is still a good idea to set that flag -in case future drivers pay attention. +Some bits are requests to the stack to try to generate timestamps. Any +combination of them is valid. Changes to these bits apply to newly +created packets, not to packets already in the stack. As a result, it +is possible to selectively request timestamps for a subset of packets +(e.g., for sampling) by embedding an send() call within two setsockopt +calls, one to enable timestamp generation and one to disable it. +Timestamps may also be generated for reasons other than being +requested by a particular socket, such as when receive timestamping is +enabled system wide, as explained earlier. -If timestamps are reported, they will appear in a control message with -cmsg_level==SOL_SOCKET, cmsg_type==SO_TIMESTAMPING, and a payload like -this: +SOF_TIMESTAMPING_RX_HARDWARE: + Request rx timestamps generated by the network adapter. + +SOF_TIMESTAMPING_RX_SOFTWARE: + Request rx timestamps when data enters the kernel. These timestamps + are generated just after a device driver hands a packet to the + kernel receive stack. + +SOF_TIMESTAMPING_TX_HARDWARE: + Request tx timestamps generated by the network adapter. + +SOF_TIMESTAMPING_TX_SOFTWARE: + Request tx timestamps when data leaves the kernel. These timestamps + are generated in the device driver as close as possible, but always + prior to, passing the packet to the network interface. Hence, they + require driver support and may not be available for all devices. + +SOF_TIMESTAMPING_TX_SCHED: + Request tx timestamps prior to entering the packet scheduler. Kernel + transmit latency is, if long, often dominated by queuing delay. The + difference between this timestamp and one taken at + SOF_TIMESTAMPING_TX_SOFTWARE will expose this latency independent + of protocol processing. The latency incurred in protocol + processing, if any, can be computed by subtracting a userspace + timestamp taken immediately before send() from this timestamp. On + machines with virtual devices where a transmitted packet travels + through multiple devices and, hence, multiple packet schedulers, + a timestamp is generated at each layer. This allows for fine + grained measurement of queuing delay. + +SOF_TIMESTAMPING_TX_ACK: + Request tx timestamps when all data in the send buffer has been + acknowledged. This only makes sense for reliable protocols. It is + currently only implemented for TCP. For that protocol, it may + over-report measurement, because the timestamp is generated when all + data up to and including the buffer at send() was acknowledged: the + cumulative acknowledgment. The mechanism ignores SACK and FACK. + + +1.3.2 Timestamp Reporting + +The other three bits control which timestamps will be reported in a +generated control message. Changes to the bits take immediate +effect at the timestamp reporting locations in the stack. Timestamps +are only reported for packets that also have the relevant timestamp +generation request set. + +SOF_TIMESTAMPING_SOFTWARE: + Report any software timestamps when available. + +SOF_TIMESTAMPING_SYS_HARDWARE: + This option is deprecated and ignored. + +SOF_TIMESTAMPING_RAW_HARDWARE: + Report hardware timestamps as generated by + SOF_TIMESTAMPING_TX_HARDWARE when available. + + +1.3.3 Timestamp Options + +The interface supports one option + +SOF_TIMESTAMPING_OPT_ID: + + Generate a unique identifier along with each packet. A process can + have multiple concurrent timestamping requests outstanding. Packets + can be reordered in the transmit path, for instance in the packet + scheduler. In that case timestamps will be queued onto the error + queue out of order from the original send() calls. This option + embeds a counter that is incremented at send() time, to order + timestamps within a flow. + + This option is implemented only for transmit timestamps. There, the + timestamp is always looped along with a struct sock_extended_err. + The option modifies field ee_info to pass an id that is unique + among all possibly concurrently outstanding timestamp requests for + that socket. In practice, it is a monotonically increasing u32 + (that wraps). + + In datagram sockets, the counter increments on each send call. In + stream sockets, it increments with every byte. + + +1.4 Bytestream Timestamps + +The SO_TIMESTAMPING interface supports timestamping of bytes in a +bytestream. Each request is interpreted as a request for when the +entire contents of the buffer has passed a timestamping point. That +is, for streams option SOF_TIMESTAMPING_TX_SOFTWARE will record +when all bytes have reached the device driver, regardless of how +many packets the data has been converted into. + +In general, bytestreams have no natural delimiters and therefore +correlating a timestamp with data is non-trivial. A range of bytes +may be split across segments, any segments may be merged (possibly +coalescing sections of previously segmented buffers associated with +independent send() calls). Segments can be reordered and the same +byte range can coexist in multiple segments for protocols that +implement retransmissions. + +It is essential that all timestamps implement the same semantics, +regardless of these possible transformations, as otherwise they are +incomparable. Handling "rare" corner cases differently from the +simple case (a 1:1 mapping from buffer to skb) is insufficient +because performance debugging often needs to focus on such outliers. + +In practice, timestamps can be correlated with segments of a +bytestream consistently, if both semantics of the timestamp and the +timing of measurement are chosen correctly. This challenge is no +different from deciding on a strategy for IP fragmentation. There, the +definition is that only the first fragment is timestamped. For +bytestreams, we chose that a timestamp is generated only when all +bytes have passed a point. SOF_TIMESTAMPING_TX_ACK as defined is easy to +implement and reason about. An implementation that has to take into +account SACK would be more complex due to possible transmission holes +and out of order arrival. + +On the host, TCP can also break the simple 1:1 mapping from buffer to +skbuff as a result of Nagle, cork, autocork, segmentation and GSO. The +implementation ensures correctness in all cases by tracking the +individual last byte passed to send(), even if it is no longer the +last byte after an skbuff extend or merge operation. It stores the +relevant sequence number in skb_shinfo(skb)->tskey. Because an skbuff +has only one such field, only one timestamp can be generated. + +In rare cases, a timestamp request can be missed if two requests are +collapsed onto the same skb. A process can detect this situation by +enabling SOF_TIMESTAMPING_OPT_ID and comparing the byte offset at +send time with the value returned for each timestamp. It can prevent +the situation by always flushing the TCP stack in between requests, +for instance by enabling TCP_NODELAY and disabling TCP_CORK and +autocork. + +These precautions ensure that the timestamp is generated only when all +bytes have passed a timestamp point, assuming that the network stack +itself does not reorder the segments. The stack indeed tries to avoid +reordering. The one exception is under administrator control: it is +possible to construct a packet scheduler configuration that delays +segments from the same stream differently. Such a setup would be +unusual. + + +2 Data Interfaces + +Timestamps are read using the ancillary data feature of recvmsg(). +See `man 3 cmsg` for details of this interface. The socket manual +page (`man 7 socket`) describes how timestamps generated with +SO_TIMESTAMP and SO_TIMESTAMPNS records can be retrieved. + + +2.1 SCM_TIMESTAMPING records + +These timestamps are returned in a control message with cmsg_level +SOL_SOCKET, cmsg_type SCM_TIMESTAMPING, and payload of type struct scm_timestamping { - struct timespec systime; - struct timespec hwtimetrans; - struct timespec hwtimeraw; + struct timespec ts[3]; }; -recvmsg() can be used to get this control message for regular incoming -packets. For send time stamps the outgoing packet is looped back to -the socket's error queue with the send time stamp(s) attached. It can -be received with recvmsg(flags=MSG_ERRQUEUE). The call returns the -original outgoing packet data including all headers preprended down to -and including the link layer, the scm_timestamping control message and -a sock_extended_err control message with ee_errno==ENOMSG and -ee_origin==SO_EE_ORIGIN_TIMESTAMPING. A socket with such a pending -bounced packet is ready for reading as far as select() is concerned. -If the outgoing packet has to be fragmented, then only the first -fragment is time stamped and returned to the sending socket. - -All three values correspond to the same event in time, but were -generated in different ways. Each of these values may be empty (= all -zero), in which case no such value was available. If the application -is not interested in some of these values, they can be left blank to -avoid the potential overhead of calculating them. - -systime is the value of the system time at that moment. This -corresponds to the value also returned via SO_TIMESTAMP[NS]. If the -time stamp was generated by hardware, then this field is -empty. Otherwise it is filled in if SOF_TIMESTAMPING_SOFTWARE is -set. - -hwtimeraw is the original hardware time stamp. Filled in if -SOF_TIMESTAMPING_RAW_HARDWARE is set. No assumptions about its -relation to system time should be made. - -hwtimetrans is always zero. This field is deprecated. It used to hold -hw timestamps converted to system time. Instead, expose the hardware -clock device on the NIC directly as a HW PTP clock source, to allow -time conversion in userspace and optionally synchronize system time -with a userspace PTP stack such as linuxptp. For the PTP clock API, -see Documentation/ptp/ptp.txt. - - -SIOCSHWTSTAMP, SIOCGHWTSTAMP: +The structure can return up to three timestamps. This is a legacy +feature. Only one field is non-zero at any time. Most timestamps +are passed in ts[0]. Hardware timestamps are passed in ts[2]. + +ts[1] used to hold hardware timestamps converted to system time. +Instead, expose the hardware clock device on the NIC directly as +a HW PTP clock source, to allow time conversion in userspace and +optionally synchronize system time with a userspace PTP stack such +as linuxptp. For the PTP clock API, see Documentation/ptp/ptp.txt. + +2.1.1 Transmit timestamps with MSG_ERRQUEUE + +For transmit timestamps the outgoing packet is looped back to the +socket's error queue with the send timestamp(s) attached. A process +receives the timestamps by calling recvmsg() with flag MSG_ERRQUEUE +set and with a msg_control buffer sufficiently large to receive the +relevant metadata structures. The recvmsg call returns the original +outgoing data packet with two ancillary messages attached. + +A message of cm_level SOL_IP(V6) and cm_type IP(V6)_RECVERR +embeds a struct sock_extended_err. This defines the error type. For +timestamps, the ee_errno field is ENOMSG. The other ancillary message +will have cm_level SOL_SOCKET and cm_type SCM_TIMESTAMPING. This +embeds the struct scm_timestamping. + + +2.1.1.2 Timestamp types + +The semantics of the three struct timespec are defined by field +ee_info in the extended error structure. It contains a value of +type SCM_TSTAMP_* to define the actual timestamp passed in +scm_timestamping. + +The SCM_TSTAMP_* types are 1:1 matches to the SOF_TIMESTAMPING_* +control fields discussed previously, with one exception. For legacy +reasons, SCM_TSTAMP_SND is equal to zero and can be set for both +SOF_TIMESTAMPING_TX_HARDWARE and SOF_TIMESTAMPING_TX_SOFTWARE. It +is the first if ts[2] is non-zero, the second otherwise, in which +case the timestamp is stored in ts[0]. + + +2.1.1.3 Fragmentation + +Fragmentation of outgoing datagrams is rare, but is possible, e.g., by +explicitly disabling PMTU discovery. If an outgoing packet is fragmented, +then only the first fragment is timestamped and returned to the sending +socket. + + +2.1.1.4 Packet Payload + +The calling application is often not interested in receiving the whole +packet payload that it passed to the stack originally: the socket +error queue mechanism is just a method to piggyback the timestamp on. +In this case, the application can choose to read datagrams with a +smaller buffer, possibly even of length 0. The payload is truncated +accordingly. Until the process calls recvmsg() on the error queue, +however, the full packet is queued, taking up budget from SO_RCVBUF. + + +2.1.1.5 Blocking Read + +Reading from the error queue is always a non-blocking operation. To +block waiting on a timestamp, use poll or select. poll() will return +POLLERR in pollfd.revents if any data is ready on the error queue. +There is no need to pass this flag in pollfd.events. This flag is +ignored on request. See also `man 2 poll`. + + +2.1.2 Receive timestamps + +On reception, there is no reason to read from the socket error queue. +The SCM_TIMESTAMPING ancillary data is sent along with the packet data +on a normal recvmsg(). Since this is not a socket error, it is not +accompanied by a message SOL_IP(V6)/IP(V6)_RECVERROR. In this case, +the meaning of the three fields in struct scm_timestamping is +implicitly defined. ts[0] holds a software timestamp if set, ts[1] +is again deprecated and ts[2] holds a hardware timestamp if set. + + +3. Hardware Timestamping configuration: SIOCSHWTSTAMP and SIOCGHWTSTAMP Hardware time stamping must also be initialized for each device driver that is expected to do hardware time stamping. The parameter is defined in @@ -167,8 +372,7 @@ enum { */ }; - -DEVICE IMPLEMENTATION +3.1 Hardware Timestamping Implementation: Device Drivers A driver which supports hardware time stamping must support the SIOCSHWTSTAMP ioctl and update the supplied struct hwtstamp_config with diff --git a/Documentation/networking/timestamping/Makefile b/Documentation/networking/timestamping/Makefile index 52ac67da9315..8c20dfaa4d6e 100644 --- a/Documentation/networking/timestamping/Makefile +++ b/Documentation/networking/timestamping/Makefile @@ -1,8 +1,14 @@ +# To compile, from the source root +# +# make headers_install +# make M=documentation + # List of programs to build -hostprogs-y := hwtstamp_config timestamping +hostprogs-y := hwtstamp_config timestamping txtimestamp # Tell kbuild to always build the programs always := $(hostprogs-y) HOSTCFLAGS_timestamping.o += -I$(objtree)/usr/include +HOSTCFLAGS_txtimestamp.o += -I$(objtree)/usr/include HOSTCFLAGS_hwtstamp_config.o += -I$(objtree)/usr/include diff --git a/Documentation/networking/timestamping/txtimestamp.c b/Documentation/networking/timestamping/txtimestamp.c new file mode 100644 index 000000000000..b32fc2a07734 --- /dev/null +++ b/Documentation/networking/timestamping/txtimestamp.c @@ -0,0 +1,469 @@ +/* + * Copyright 2014 Google Inc. + * Author: willemb@google.com (Willem de Bruijn) + * + * Test software tx timestamping, including + * + * - SCHED, SND and ACK timestamps + * - RAW, UDP and TCP + * - IPv4 and IPv6 + * - various packet sizes (to test GSO and TSO) + * + * Consult the command line arguments for help on running + * the various testcases. + * + * This test requires a dummy TCP server. + * A simple `nc6 [-u] -l -p $DESTPORT` will do + * + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. * See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include <arpa/inet.h> +#include <asm/types.h> +#include <error.h> +#include <errno.h> +#include <linux/errqueue.h> +#include <linux/if_ether.h> +#include <linux/net_tstamp.h> +#include <netdb.h> +#include <net/if.h> +#include <netinet/in.h> +#include <netinet/ip.h> +#include <netinet/udp.h> +#include <netinet/tcp.h> +#include <netpacket/packet.h> +#include <poll.h> +#include <stdarg.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/ioctl.h> +#include <sys/select.h> +#include <sys/socket.h> +#include <sys/time.h> +#include <sys/types.h> +#include <time.h> +#include <unistd.h> + +/* command line parameters */ +static int cfg_proto = SOCK_STREAM; +static int cfg_ipproto = IPPROTO_TCP; +static int cfg_num_pkts = 4; +static int do_ipv4 = 1; +static int do_ipv6 = 1; +static int cfg_payload_len = 10; +static uint16_t dest_port = 9000; + +static struct sockaddr_in daddr; +static struct sockaddr_in6 daddr6; +static struct timespec ts_prev; + +static void __print_timestamp(const char *name, struct timespec *cur, + uint32_t key, int payload_len) +{ + if (!(cur->tv_sec | cur->tv_nsec)) + return; + + fprintf(stderr, " %s: %lu s %lu us (seq=%u, len=%u)", + name, cur->tv_sec, cur->tv_nsec / 1000, + key, payload_len); + + if ((ts_prev.tv_sec | ts_prev.tv_nsec)) { + int64_t cur_ms, prev_ms; + + cur_ms = (long) cur->tv_sec * 1000 * 1000; + cur_ms += cur->tv_nsec / 1000; + + prev_ms = (long) ts_prev.tv_sec * 1000 * 1000; + prev_ms += ts_prev.tv_nsec / 1000; + + fprintf(stderr, " (%+ld us)", cur_ms - prev_ms); + } + + ts_prev = *cur; + fprintf(stderr, "\n"); +} + +static void print_timestamp_usr(void) +{ + struct timespec ts; + struct timeval tv; /* avoid dependency on -lrt */ + + gettimeofday(&tv, NULL); + ts.tv_sec = tv.tv_sec; + ts.tv_nsec = tv.tv_usec * 1000; + + __print_timestamp(" USR", &ts, 0, 0); +} + +static void print_timestamp(struct scm_timestamping *tss, int tstype, + int tskey, int payload_len) +{ + const char *tsname; + + switch (tstype) { + case SCM_TSTAMP_SCHED: + tsname = " ENQ"; + break; + case SCM_TSTAMP_SND: + tsname = " SND"; + break; + case SCM_TSTAMP_ACK: + tsname = " ACK"; + break; + default: + error(1, 0, "unknown timestamp type: %u", + tstype); + } + __print_timestamp(tsname, &tss->ts[0], tskey, payload_len); +} + +static void __poll(int fd) +{ + struct pollfd pollfd; + int ret; + + memset(&pollfd, 0, sizeof(pollfd)); + pollfd.fd = fd; + ret = poll(&pollfd, 1, 100); + if (ret != 1) + error(1, errno, "poll"); +} + +static void __recv_errmsg_cmsg(struct msghdr *msg, int payload_len) +{ + struct sock_extended_err *serr = NULL; + struct scm_timestamping *tss = NULL; + struct cmsghdr *cm; + + for (cm = CMSG_FIRSTHDR(msg); + cm && cm->cmsg_len; + cm = CMSG_NXTHDR(msg, cm)) { + if (cm->cmsg_level == SOL_SOCKET && + cm->cmsg_type == SCM_TIMESTAMPING) { + tss = (void *) CMSG_DATA(cm); + } else if ((cm->cmsg_level == SOL_IP && + cm->cmsg_type == IP_RECVERR) || + (cm->cmsg_level == SOL_IPV6 && + cm->cmsg_type == IPV6_RECVERR)) { + + serr = (void *) CMSG_DATA(cm); + if (serr->ee_errno != ENOMSG || + serr->ee_origin != SO_EE_ORIGIN_TIMESTAMPING) { + fprintf(stderr, "unknown ip error %d %d\n", + serr->ee_errno, + serr->ee_origin); + serr = NULL; + } + } else + fprintf(stderr, "unknown cmsg %d,%d\n", + cm->cmsg_level, cm->cmsg_type); + } + + if (serr && tss) + print_timestamp(tss, serr->ee_info, serr->ee_data, payload_len); +} + +static int recv_errmsg(int fd) +{ + static char ctrl[1024 /* overprovision*/]; + static struct msghdr msg; + struct iovec entry; + static char *data; + int ret = 0; + + data = malloc(cfg_payload_len); + if (!data) + error(1, 0, "malloc"); + + memset(&msg, 0, sizeof(msg)); + memset(&entry, 0, sizeof(entry)); + memset(ctrl, 0, sizeof(ctrl)); + + entry.iov_base = data; + entry.iov_len = cfg_payload_len; + msg.msg_iov = &entry; + msg.msg_iovlen = 1; + msg.msg_name = NULL; + msg.msg_namelen = 0; + msg.msg_control = ctrl; + msg.msg_controllen = sizeof(ctrl); + + ret = recvmsg(fd, &msg, MSG_ERRQUEUE); + if (ret == -1 && errno != EAGAIN) + error(1, errno, "recvmsg"); + + __recv_errmsg_cmsg(&msg, ret); + + free(data); + return ret == -1; +} + +static void do_test(int family, unsigned int opt) +{ + char *buf; + int fd, i, val, total_len; + + if (family == IPPROTO_IPV6 && cfg_proto != SOCK_STREAM) { + /* due to lack of checksum generation code */ + fprintf(stderr, "test: skipping datagram over IPv6\n"); + return; + } + + total_len = cfg_payload_len; + if (cfg_proto == SOCK_RAW) { + total_len += sizeof(struct udphdr); + if (cfg_ipproto == IPPROTO_RAW) + total_len += sizeof(struct iphdr); + } + + buf = malloc(total_len); + if (!buf) + error(1, 0, "malloc"); + + fd = socket(family, cfg_proto, cfg_ipproto); + if (fd < 0) + error(1, errno, "socket"); + + if (cfg_proto == SOCK_STREAM) { + val = 1; + if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, + (char*) &val, sizeof(val))) + error(1, 0, "setsockopt no nagle"); + + if (family == PF_INET) { + if (connect(fd, (void *) &daddr, sizeof(daddr))) + error(1, errno, "connect ipv4"); + } else { + if (connect(fd, (void *) &daddr6, sizeof(daddr6))) + error(1, errno, "connect ipv6"); + } + } + + opt |= SOF_TIMESTAMPING_SOFTWARE | + SOF_TIMESTAMPING_OPT_ID; + if (setsockopt(fd, SOL_SOCKET, SO_TIMESTAMPING, + (char *) &opt, sizeof(opt))) + error(1, 0, "setsockopt timestamping"); + + for (i = 0; i < cfg_num_pkts; i++) { + memset(&ts_prev, 0, sizeof(ts_prev)); + memset(buf, 'a' + i, total_len); + buf[total_len - 2] = '\n'; + buf[total_len - 1] = '\0'; + + if (cfg_proto == SOCK_RAW) { + struct udphdr *udph; + int off = 0; + + if (cfg_ipproto == IPPROTO_RAW) { + struct iphdr *iph = (void *) buf; + + memset(iph, 0, sizeof(*iph)); + iph->ihl = 5; + iph->version = 4; + iph->ttl = 2; + iph->daddr = daddr.sin_addr.s_addr; + iph->protocol = IPPROTO_UDP; + /* kernel writes saddr, csum, len */ + + off = sizeof(*iph); + } + + udph = (void *) buf + off; + udph->source = ntohs(9000); /* random spoof */ + udph->dest = ntohs(dest_port); + udph->len = ntohs(sizeof(*udph) + cfg_payload_len); + udph->check = 0; /* not allowed for IPv6 */ + } + + print_timestamp_usr(); + if (cfg_proto != SOCK_STREAM) { + if (family == PF_INET) + val = sendto(fd, buf, total_len, 0, (void *) &daddr, sizeof(daddr)); + else + val = sendto(fd, buf, total_len, 0, (void *) &daddr6, sizeof(daddr6)); + } else { + val = send(fd, buf, cfg_payload_len, 0); + } + if (val != total_len) + error(1, errno, "send"); + + /* wait for all errors to be queued, else ACKs arrive OOO */ + usleep(50 * 1000); + + __poll(fd); + + while (!recv_errmsg(fd)) {} + } + + if (close(fd)) + error(1, errno, "close"); + + free(buf); + usleep(400 * 1000); +} + +static void __attribute__((noreturn)) usage(const char *filepath) +{ + fprintf(stderr, "\nUsage: %s [options] hostname\n" + "\nwhere options are:\n" + " -4: only IPv4\n" + " -6: only IPv6\n" + " -h: show this message\n" + " -l N: send N bytes at a time\n" + " -r: use raw\n" + " -R: use raw (IP_HDRINCL)\n" + " -p N: connect to port N\n" + " -u: use udp\n", + filepath); + exit(1); +} + +static void parse_opt(int argc, char **argv) +{ + int proto_count = 0; + char c; + + while ((c = getopt(argc, argv, "46hl:p:rRu")) != -1) { + switch (c) { + case '4': + do_ipv6 = 0; + break; + case '6': + do_ipv4 = 0; + break; + case 'r': + proto_count++; + cfg_proto = SOCK_RAW; + cfg_ipproto = IPPROTO_UDP; + break; + case 'R': + proto_count++; + cfg_proto = SOCK_RAW; + cfg_ipproto = IPPROTO_RAW; + break; + case 'u': + proto_count++; + cfg_proto = SOCK_DGRAM; + cfg_ipproto = IPPROTO_UDP; + break; + case 'l': + cfg_payload_len = strtoul(optarg, NULL, 10); + break; + case 'p': + dest_port = strtoul(optarg, NULL, 10); + break; + case 'h': + default: + usage(argv[0]); + } + } + + if (!cfg_payload_len) + error(1, 0, "payload may not be nonzero"); + if (cfg_proto != SOCK_STREAM && cfg_payload_len > 1472) + error(1, 0, "udp packet might exceed expected MTU"); + if (!do_ipv4 && !do_ipv6) + error(1, 0, "pass -4 or -6, not both"); + if (proto_count > 1) + error(1, 0, "pass -r, -R or -u, not multiple"); + + if (optind != argc - 1) + error(1, 0, "missing required hostname argument"); +} + +static void resolve_hostname(const char *hostname) +{ + struct addrinfo *addrs, *cur; + int have_ipv4 = 0, have_ipv6 = 0; + + if (getaddrinfo(hostname, NULL, NULL, &addrs)) + error(1, errno, "getaddrinfo"); + + cur = addrs; + while (cur && !have_ipv4 && !have_ipv6) { + if (!have_ipv4 && cur->ai_family == AF_INET) { + memcpy(&daddr, cur->ai_addr, sizeof(daddr)); + daddr.sin_port = htons(dest_port); + have_ipv4 = 1; + } + else if (!have_ipv6 && cur->ai_family == AF_INET6) { + memcpy(&daddr6, cur->ai_addr, sizeof(daddr6)); + daddr6.sin6_port = htons(dest_port); + have_ipv6 = 1; + } + cur = cur->ai_next; + } + if (addrs) + freeaddrinfo(addrs); + + do_ipv4 &= have_ipv4; + do_ipv6 &= have_ipv6; +} + +static void do_main(int family) +{ + fprintf(stderr, "family: %s\n", + family == PF_INET ? "INET" : "INET6"); + + fprintf(stderr, "test SND\n"); + do_test(family, SOF_TIMESTAMPING_TX_SOFTWARE); + + fprintf(stderr, "test ENQ\n"); + do_test(family, SOF_TIMESTAMPING_TX_SCHED); + + fprintf(stderr, "test ENQ + SND\n"); + do_test(family, SOF_TIMESTAMPING_TX_SCHED | + SOF_TIMESTAMPING_TX_SOFTWARE); + + if (cfg_proto == SOCK_STREAM) { + fprintf(stderr, "\ntest ACK\n"); + do_test(family, SOF_TIMESTAMPING_TX_ACK); + + fprintf(stderr, "\ntest SND + ACK\n"); + do_test(family, SOF_TIMESTAMPING_TX_SOFTWARE | + SOF_TIMESTAMPING_TX_ACK); + + fprintf(stderr, "\ntest ENQ + SND + ACK\n"); + do_test(family, SOF_TIMESTAMPING_TX_SCHED | + SOF_TIMESTAMPING_TX_SOFTWARE | + SOF_TIMESTAMPING_TX_ACK); + } +} + +const char *sock_names[] = { NULL, "TCP", "UDP", "RAW" }; + +int main(int argc, char **argv) +{ + if (argc == 1) + usage(argv[0]); + + parse_opt(argc, argv); + resolve_hostname(argv[argc - 1]); + + fprintf(stderr, "protocol: %s\n", sock_names[cfg_proto]); + fprintf(stderr, "payload: %u\n", cfg_payload_len); + fprintf(stderr, "server port: %u\n", dest_port); + fprintf(stderr, "\n"); + + if (do_ipv4) + do_main(PF_INET); + if (do_ipv6) + do_main(PF_INET6); + + return 0; +} |