Bpf tcp dataNov 17, 2017 · 23568 4 837 227 https://www.wireshark.org. You can try the Wireshark (and tshark) display filter ! (tcp.analysis.retransmission or tcp.analysis.fast_retransmission). You can't use capture (BPF) filters as they have no knowledge of previous transmissions. Preview: (hide) BPF syntax. The expression consists of one or more primitives. Primitives usually consist of an id (name or number) preceded by one or more qualifiers. There are three different kinds of qualifier: type. qualifiers say what kind of thing the id name or number refers to. Possible types are host , net , port and portrange . Such an exposure in BPF is thus required to be able to differentiate plain TCP sockets from MPTCP subflow sockets in BPF_PROG_TYPE_SOCK_OPS programs. The choice has been made to silently pass the case when CONFIG_MPTCP is unset by defaulting is_mptcp to 0 in order to make BPF independent of the MPTCP configuration. From: Cong Wang <[email protected]> To: [email protected] Cc: [email protected], [email protected], [email protected], [email protected], Cong Wang <[email protected]>, John Fastabend <[email protected]>, Daniel Borkmann <[email protected]>, Jakub Sitnicki <[email protected]>, Lorenz Bauer <[email protected]> Subject: [Patch bpf ...Such an exposure in BPF is thus required to be able to differentiate plain TCP sockets from MPTCP subflow sockets in BPF_PROG_TYPE_SOCK_OPS programs. The choice has been made to silently pass the case when CONFIG_MPTCP is unset by defaulting is_mptcp to 0 in order to make BPF independent of the MPTCP configuration. This section explains what the BPF Compiler Collection (BCC) is, how you install the BCC, as well as how to perform different network tracing operations using the pre-created scripts provided by the bcc-tools package. All of these scripts support the --ebpf parameter to display the eBPF code the utility uploads to the kernel. You can use the code to learn more about writing eBPF scripts.Message ID: [email protected] (mailing list archive)State: Superseded: Delegated to: BPF: Headers: show Message ID: [email protected] (mailing list archive)State: Superseded: Delegated to: BPF: Headers: show May 26, 2020 · bpf: pass sk struct to tcp_parse_options () This is necessary for calling TCP-BPF hook since skb->sk is not always set. We can simplify tcp_parse_options () by removing the net namespace struct from the argument list. However, it is also called with timewait sock in tcp_timewait_state_process (). When the old bpf-tcp-cc is calling setsockopt(TCP_CONGESTION) to switch to a new cc, the old bpf-tcp-cc will be released by bpf_struct_ops_put(). Thus, this patch also puts the bpf_struct_ops_map after a rcu grace period because the trampoline's image cannot be freed while the old bpf-tcp-cc is still running. The helper returns a pointer to a struct bpf_tcp_sock object, describe in the first link. The file is GPL, but note that this is a user API header (no code, just definitions for user applications - even if they're not GPL) so I don't know what restrictions apply.Message ID: [email protected] (mailing list archive)State: Superseded: Delegated to: BPF: Headers: showused class a motorhomes for sale in paMessage ID: [email protected] (mailing list archive)State: Superseded: Delegated to: BPF: Headers: showThe BPF code emitted by this primitive is complex and cannot be optimized by BPF optimizer code in tcpdump , so this can be somewhat slow. ip protochain protocol Equivalent to ip6 protochain protocol, but this is for IPv4. ether broadcast True if the packet is an Ethernet broadcast packet. The ether keyword is optional. ip broadcastMessage ID: [email protected] (mailing list archive)State: Superseded: Delegated to: BPF: Headers: show From: Cong Wang <[email protected]> To: [email protected] Cc: [email protected], [email protected], [email protected], [email protected], Cong Wang <[email protected]>, John Fastabend <[email protected]>, Daniel Borkmann <[email protected]>, Jakub Sitnicki <[email protected]>, Lorenz Bauer <[email protected]> Subject: [Patch bpf ...May 26, 2020 · bpf: pass sk struct to tcp_parse_options () This is necessary for calling TCP-BPF hook since skb->sk is not always set. We can simplify tcp_parse_options () by removing the net namespace struct from the argument list. However, it is also called with timewait sock in tcp_timewait_state_process (). BPF TCP OPTIONS SIZE CALC tcp transmit skb Length of all TCP options Call BPF program to adjust tcp current mss the length of all TCP options BPF TCP OPTIONS WRITE tcp options write - Call BPF program to insert new TCP option BPF TCP PARSE OPTIONS tcp parse options Option kind, len, and value Pass unknown TCP option to BPF program Table 1: New ...BPF Compiler Collection is a set of tools, known as BCC tools, that analyze OS and network performance. This article will cover the basics of the toolkit, pitfalls of the package, and some alternatives to it.Message ID: [email protected] (mailing list archive)State: Superseded: Delegated to: BPF: Headers: show Message ID: [email protected] (mailing list archive)State: Accepted: Delegated to: BPF: Headers: showslader physicsMessage ID: [email protected] (mailing list archive)State: Superseded: Delegated to: BPF: Headers: show* [PATCH v3 bpf-next 0/9] BPF TCP header options @ 2020-07-30 20:56 Martin KaFai Lau 2020-07-30 20:57 ` [PATCH v3 bpf-next 1/9] tcp: Use a struct to represent a saved_syn Martin KaFai Lau ` (8 more replies) 0 siblings, 9 replies; 17+ messages in thread From: Martin KaFai Lau @ 2020-07-30 20:56 UTC (permalink / raw May 26, 2020 · bpf: pass sk struct to tcp_parse_options () This is necessary for calling TCP-BPF hook since skb->sk is not always set. We can simplify tcp_parse_options () by removing the net namespace struct from the argument list. However, it is also called with timewait sock in tcp_timewait_state_process (). Primitives Primitives are references to fields in a network protocol header, such as host, port, or TCP port. The BPF syntax consists of one or more primitives, which usually consist of an ID, typically a name or number, which is preceded by one or more qualifiers. Type qualifiersPrimitives are references to fields in a network protocol header, such as host, port, or TCP port. The BPF syntax consists of one or more primitives, which usually consist of an ID, typically a name or number, which is preceded by one or more qualifiers. Type qualifiers packet and BPF must collect the data from several packets and return it as a unit when the monitoring application does a read. To maintain packet boundaries, BPF encapsulates the captured data from each packet with a header that includes a time stamp, length, and offsets for data alignment. 2.1 Packet FilteringWe can use the following ways to capture packets with syn TCP flag. Syn flag is 00000010 in tcp header. That is 2 in decimal. tcpdump -i utun1 tcp [tcpflags] == 'tcp-syn' tcpdump -i utun1 tcp [13] == 2 The following TCP flag field values are also available: tcp-fin, tcp-syn, tcp-rst, tcp-push, tcp-act, tcp-urg.Message ID: [email protected] (mailing list archive)State: Accepted: Delegated to: BPF: Headers: showSep 28, 2021 · BPF, Berkeley Packet Filter, is a technology that was originally developed to analyze and filter network traffic. It allows the user to run user-supplied programs inside the operating system kernel in a special BPF virtual machine. Later on, in Linux, it was extended (hence eBPF - extended BPF) to support more use-cases, among-others, tracing. 3 hours ago · Joanne Koong April 2, 2022, 1:58 a.m. UTC. From: Joanne Koong <[email protected]> This article describes using eBPF (extended BPF), an extended version of the Berkeley Packet Filter, ... with documentation and the SDK not yet ready. But that should improve, especially with XDP (eXpress Data Path) being shipped in Red Hat Enterprise Linux 8, which you can download and run now. ... clang -O2 -target bpf -c tcp_psh.c -o tcp_psh.o.* [PATCH v3 bpf-next 0/9] BPF TCP header options @ 2020-07-30 20:56 Martin KaFai Lau 2020-07-30 20:57 ` [PATCH v3 bpf-next 1/9] tcp: Use a struct to represent a saved_syn Martin KaFai Lau ` (8 more replies) 0 siblings, 9 replies; 17+ messages in thread From: Martin KaFai Lau @ 2020-07-30 20:56 UTC (permalink / raw Here's what the BPF will look like: ip[0] & 0xF0 = 0x04 (our search value). Broken down, we are telling tcpdump to look at the IP header (ip), first byte offset from 0 ( [0] ), retain all the bits in the first nibble and discard all the bits in the low order nibble ( & 0xF0 ) and show us all the packets with a value of 4 in that nibble ( = 4).dual band hotspotMay 26, 2020 · bpf: pass sk struct to tcp_parse_options () This is necessary for calling TCP-BPF hook since skb->sk is not always set. We can simplify tcp_parse_options () by removing the net namespace struct from the argument list. However, it is also called with timewait sock in tcp_timewait_state_process (). May 26, 2020 · bpf: pass sk struct to tcp_parse_options () This is necessary for calling TCP-BPF hook since skb->sk is not always set. We can simplify tcp_parse_options () by removing the net namespace struct from the argument list. However, it is also called with timewait sock in tcp_timewait_state_process (). Message ID: [email protected] (mailing list archive)State: Accepted: Delegated to: BPF: Headers: showMar 31, 2022 · BPF Iterator: Retrieving Kernel Data With Flexibility and Efficiency. The BPF iterator enables high-performance, in-kernel data retrieval and aggregation. In this blog post, we talk about the motivation behind developing the bpf iterator tool and using it to retrieve kernel data into user space flexibly and efficiently. * [PATCH v3 bpf-next 0/9] BPF TCP header options @ 2020-07-30 20:56 Martin KaFai Lau 2020-07-30 20:57 ` [PATCH v3 bpf-next 1/9] tcp: Use a struct to represent a saved_syn Martin KaFai Lau ` (8 more replies) 0 siblings, 9 replies; 17+ messages in thread From: Martin KaFai Lau @ 2020-07-30 20:56 UTC (permalink / raw dst port 80 and tcp [ (tcp [12]>>2):4]=0x47455420 The reason it must be done in this way is that you must account for the possibility of changing TCP options and, as a result, changing locations for where the data offset begins. This figures out where the data starts and examines the first four bytes for the string "GET ".3 hours ago · Joanne Koong April 2, 2022, 1:58 a.m. UTC. From: Joanne Koong <[email protected]> Message ID: [email protected] (mailing list archive)State: Superseded: Delegated to: BPF: Headers: show Jan 24, 2019 · There are a few options for us to choose from, but a "tc" bpf program makes most sense. tc supports symmetric (ingress and egress) program attach, and the advantage of using XDP - not having to allocate packet metadata - doesn't really buy us much here, since we want to pass our packet upstream to the Linux TCP/IP stack. Such an exposure in BPF is thus required to be able to differentiate plain TCP sockets from MPTCP subflow sockets in BPF_PROG_TYPE_SOCK_OPS programs. The choice has been made to silently pass the case when CONFIG_MPTCP is unset by defaulting is_mptcp to 0 in order to make BPF independent of the MPTCP configuration. TCP HEADER - RFC 793 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Offset 0 Offset 1 Offset 2 Offset 3rcd360 vs rcd330Message ID: [email protected] (mailing list archive)State: Superseded: Delegated to: BPF: Headers: show* [PATCH v3 bpf-next 0/9] BPF TCP header options @ 2020-07-30 20:56 Martin KaFai Lau 2020-07-30 20:57 ` [PATCH v3 bpf-next 1/9] tcp: Use a struct to represent a saved_syn Martin KaFai Lau ` (8 more replies) 0 siblings, 9 replies; 17+ messages in thread From: Martin KaFai Lau @ 2020-07-30 20:56 UTC (permalink / raw May 26, 2020 · bpf: pass sk struct to tcp_parse_options () This is necessary for calling TCP-BPF hook since skb->sk is not always set. We can simplify tcp_parse_options () by removing the net namespace struct from the argument list. However, it is also called with timewait sock in tcp_timewait_state_process (). This article describes using eBPF (extended BPF), an extended version of the Berkeley Packet Filter, ... with documentation and the SDK not yet ready. But that should improve, especially with XDP (eXpress Data Path) being shipped in Red Hat Enterprise Linux 8, which you can download and run now. ... clang -O2 -target bpf -c tcp_psh.c -o tcp_psh.o.Oct 05, 2021 · To keep it simple, since initially this was about learning BPF for me, my first attempt was to use the combination of remote IP address and a magic source port number of a TCP connection to trigger the BPF program. Let’s say a packet comes in on port 6666, then the BPF program wakes up and does malicious stuff. resizable bar amdExample invocation with the previous classifier and action mixture: tc exec bpf imp /tmp/bpf tc filter add dev em1 parent 1: bpf obj bpf.o exp /tmp/bpf flowid 1:1 \ action bpf obj bpf.o sec action-mark \ action bpf obj bpf.o sec action-rand ok Assuming that eBPF maps are shared with classifier and actions, it's enough to export them once, for ...Message ID: [email protected] (mailing list archive)State: Superseded: Delegated to: BPF: Headers: show Such an exposure in BPF is thus required to be able to differentiate plain TCP sockets from MPTCP subflow sockets in BPF_PROG_TYPE_SOCK_OPS programs. The choice has been made to silently pass the case when CONFIG_MPTCP is unset by defaulting is_mptcp to 0 in order to make BPF independent of the MPTCP configuration. Such an exposure in BPF is thus required to be able to differentiate plain TCP sockets from MPTCP subflow sockets in BPF_PROG_TYPE_SOCK_OPS programs. The choice has been made to silently pass the case when CONFIG_MPTCP is unset by defaulting is_mptcp to 0 in order to make BPF independent of the MPTCP configuration. Message ID: [email protected] (mailing list archive)State: Superseded: Delegated to: BPF: Headers: show* [PATCH v3 bpf-next 0/9] BPF TCP header options @ 2020-07-30 20:56 Martin KaFai Lau 2020-07-30 20:57 ` [PATCH v3 bpf-next 1/9] tcp: Use a struct to represent a saved_syn Martin KaFai Lau ` (8 more replies) 0 siblings, 9 replies; 17+ messages in thread From: Martin KaFai Lau @ 2020-07-30 20:56 UTC (permalink / raw Jan 24, 2019 · There are a few options for us to choose from, but a "tc" bpf program makes most sense. tc supports symmetric (ingress and egress) program attach, and the advantage of using XDP - not having to allocate packet metadata - doesn't really buy us much here, since we want to pass our packet upstream to the Linux TCP/IP stack. Mar 31, 2022 · BPF Iterator: Retrieving Kernel Data With Flexibility and Efficiency. The BPF iterator enables high-performance, in-kernel data retrieval and aggregation. In this blog post, we talk about the motivation behind developing the bpf iterator tool and using it to retrieve kernel data into user space flexibly and efficiently. 1: tcp 127.0.0.1/32 80 -> "foo" 2: tcp 127.0.0.0/24 80 -> "bar". The first binding should be matched before the second one. We need to encode this in the BPF somehow. One idea is to generate some code that executes the bindings in order of specificity, a technique we've used to great effect in l4drop:Mar 31, 2022 · BPF Iterator: Retrieving Kernel Data With Flexibility and Efficiency. The BPF iterator enables high-performance, in-kernel data retrieval and aggregation. In this blog post, we talk about the motivation behind developing the bpf iterator tool and using it to retrieve kernel data into user space flexibly and efficiently. Message ID: [email protected] (mailing list archive)State: Superseded: Delegated to: BPF: Headers: show May 26, 2020 · bpf: pass sk struct to tcp_parse_options () This is necessary for calling TCP-BPF hook since skb->sk is not always set. We can simplify tcp_parse_options () by removing the net namespace struct from the argument list. However, it is also called with timewait sock in tcp_timewait_state_process (). BPF Compiler Collection is a set of tools, known as BCC tools, that analyze OS and network performance. This article will cover the basics of the toolkit, pitfalls of the package, and some alternatives to it.This article describes using eBPF (extended BPF), an extended version of the Berkeley Packet Filter, ... with documentation and the SDK not yet ready. But that should improve, especially with XDP (eXpress Data Path) being shipped in Red Hat Enterprise Linux 8, which you can download and run now. ... clang -O2 -target bpf -c tcp_psh.c -o tcp_psh.o.This article describes using eBPF (extended BPF), an extended version of the Berkeley Packet Filter, ... with documentation and the SDK not yet ready. But that should improve, especially with XDP (eXpress Data Path) being shipped in Red Hat Enterprise Linux 8, which you can download and run now. ... clang -O2 -target bpf -c tcp_psh.c -o tcp_psh.o.Message ID: [email protected] (mailing list archive)State: Superseded: Delegated to: BPF: Headers: show Example invocation with the previous classifier and action mixture: tc exec bpf imp /tmp/bpf tc filter add dev em1 parent 1: bpf obj bpf.o exp /tmp/bpf flowid 1:1 \ action bpf obj bpf.o sec action-mark \ action bpf obj bpf.o sec action-rand ok Assuming that eBPF maps are shared with classifier and actions, it's enough to export them once, for ...american income life glassdoor salaryMay 26, 2020 · bpf: pass sk struct to tcp_parse_options () This is necessary for calling TCP-BPF hook since skb->sk is not always set. We can simplify tcp_parse_options () by removing the net namespace struct from the argument list. However, it is also called with timewait sock in tcp_timewait_state_process (). static u64 sk_get_syn_data (const struct tcp_sock * tp) { /* extract tp->syn_data bitfield value */ return BPF_CORE_READ_BITFIELD_PROBED(tp, syn_data); } As simple as that. With BCC, achieving the same would result in something like this (it is left as an exercise to the reader on why this works and when it would break):Message ID: [email protected] (mailing list archive)State: Superseded: Delegated to: BPF: Headers: show To transmit the frames, the new mode instantiates a page_pool structure in bpf_prog_run() and initialises the pages to contain XDP frames with the data passed in by userspace. These frames can then be handled as though they came from the hardware XDP path, and the existing page_pool code takes care of returning and recycling them. The BPF code emitted by this primitive is complex and cannot be optimized by BPF optimizer code in tcpdump , so this can be somewhat slow. ip protochain protocol Equivalent to ip6 protochain protocol, but this is for IPv4. ether broadcast True if the packet is an Ethernet broadcast packet. The ether keyword is optional. ip broadcastBPF Compiler Collection is a set of tools, known as BCC tools, that analyze OS and network performance. This article will cover the basics of the toolkit, pitfalls of the package, and some alternatives to it.Mar 31, 2022 · BPF Iterator: Retrieving Kernel Data With Flexibility and Efficiency. The BPF iterator enables high-performance, in-kernel data retrieval and aggregation. In this blog post, we talk about the motivation behind developing the bpf iterator tool and using it to retrieve kernel data into user space flexibly and efficiently. * [PATCH v3 bpf-next 0/9] BPF TCP header options @ 2020-07-30 20:56 Martin KaFai Lau 2020-07-30 20:57 ` [PATCH v3 bpf-next 1/9] tcp: Use a struct to represent a saved_syn Martin KaFai Lau ` (8 more replies) 0 siblings, 9 replies; 17+ messages in thread From: Martin KaFai Lau @ 2020-07-30 20:56 UTC (permalink / raw TCP-BPF allows BPF programs to read and write to many fields of data structures (tcp_sock) maintained by the TCP stack via a mirror structure bpf_sock_ops. It also provides access to other internal TCP variables via indirect bpf_getsockopt() and bpf_setsockopt() helper functions. • BPF_MAP_TYPE_ARRAY_OF_MAPS: a map-in-map data structure • BPF_MAP_TYPE_HASH_OF_MAPS: a map-in-map data structure • BPF_MAP_TYPE_DEVICE_MAP: for storing and looking up network device references • BPF_MAP_TYPE_SOCKET_MAP: stores and looks up sockets and allows socket redirection with BPF helper functions 3 hours ago · Joanne Koong April 2, 2022, 1:58 a.m. UTC. From: Joanne Koong <[email protected]> Such an exposure in BPF is thus required to be able to differentiate plain TCP sockets from MPTCP subflow sockets in BPF_PROG_TYPE_SOCK_OPS programs. The choice has been made to silently pass the case when CONFIG_MPTCP is unset by defaulting is_mptcp to 0 in order to make BPF independent of the MPTCP configuration. Message ID: [email protected] (mailing list archive)State: Superseded: Delegated to: BPF: Headers: show Message ID: [email protected] (mailing list archive)State: Superseded: Delegated to: BPF: Headers: show Mar 31, 2022 · BPF Iterator: Retrieving Kernel Data With Flexibility and Efficiency. The BPF iterator enables high-performance, in-kernel data retrieval and aggregation. In this blog post, we talk about the motivation behind developing the bpf iterator tool and using it to retrieve kernel data into user space flexibly and efficiently. May 26, 2020 · bpf: pass sk struct to tcp_parse_options () This is necessary for calling TCP-BPF hook since skb->sk is not always set. We can simplify tcp_parse_options () by removing the net namespace struct from the argument list. However, it is also called with timewait sock in tcp_timewait_state_process (). gta 5 packie mcreary not appearingBPF Compiler Collection is a set of tools, known as BCC tools, that analyze OS and network performance. This article will cover the basics of the toolkit, pitfalls of the package, and some alternatives to it.Message ID: [email protected] (mailing list archive)State: Superseded: Delegated to: BPF: Headers: show Mar 31, 2022 · BPF Iterator: Retrieving Kernel Data With Flexibility and Efficiency. The BPF iterator enables high-performance, in-kernel data retrieval and aggregation. In this blog post, we talk about the motivation behind developing the bpf iterator tool and using it to retrieve kernel data into user space flexibly and efficiently. This article describes using eBPF (extended BPF), an extended version of the Berkeley Packet Filter, ... with documentation and the SDK not yet ready. But that should improve, especially with XDP (eXpress Data Path) being shipped in Red Hat Enterprise Linux 8, which you can download and run now. ... clang -O2 -target bpf -c tcp_psh.c -o tcp_psh.o.Message ID: [email protected] (mailing list archive)State: Superseded: Delegated to: BPF: Headers: show May 26, 2020 · bpf: pass sk struct to tcp_parse_options () This is necessary for calling TCP-BPF hook since skb->sk is not always set. We can simplify tcp_parse_options () by removing the net namespace struct from the argument list. However, it is also called with timewait sock in tcp_timewait_state_process (). 3 hours ago · Joanne Koong April 2, 2022, 1:58 a.m. UTC. From: Joanne Koong <[email protected]> * [PATCH v3 bpf-next 0/9] BPF TCP header options @ 2020-07-30 20:56 Martin KaFai Lau 2020-07-30 20:57 ` [PATCH v3 bpf-next 1/9] tcp: Use a struct to represent a saved_syn Martin KaFai Lau ` (8 more replies) 0 siblings, 9 replies; 17+ messages in thread From: Martin KaFai Lau @ 2020-07-30 20:56 UTC (permalink / raw Dec 04, 2008 · Load the half word at offset 12. If it's the IP Ethertype, you get the whole packet. If it's not IP, go to the next instruction. If it's a 802.1Q VLAN tag, again you get the whole packet. Otherwise, return nothing. This is the other option. $ tcpdump -d -n -r sample.pcap vlan or ip. labelimg tool3 hours ago · Joanne Koong April 2, 2022, 1:58 a.m. UTC. From: Joanne Koong <[email protected]> BPF TCP OPTIONS SIZE CALC tcp transmit skb Length of all TCP options Call BPF program to adjust tcp current mss the length of all TCP options BPF TCP OPTIONS WRITE tcp options write - Call BPF program to insert new TCP option BPF TCP PARSE OPTIONS tcp parse options Option kind, len, and value Pass unknown TCP option to BPF program Table 1: New ...When the old bpf-tcp-cc is calling setsockopt(TCP_CONGESTION) to switch to a new cc, the old bpf-tcp-cc will be released by bpf_struct_ops_put(). Thus, this patch also puts the bpf_struct_ops_map after a rcu grace period because the trampoline's image cannot be freed while the old bpf-tcp-cc is still running. BPF TCP OPTIONS SIZE CALC tcp transmit skb Length of all TCP options Call BPF program to adjust tcp current mss the length of all TCP options BPF TCP OPTIONS WRITE tcp options write - Call BPF program to insert new TCP option BPF TCP PARSE OPTIONS tcp parse options Option kind, len, and value Pass unknown TCP option to BPF program Table 1: New ...Message ID: [email protected] (mailing list archive)State: Superseded: Delegated to: BPF: Headers: show When the old bpf-tcp-cc is calling setsockopt(TCP_CONGESTION) to switch to a new cc, the old bpf-tcp-cc will be released by bpf_struct_ops_put(). Thus, this patch also puts the bpf_struct_ops_map after a rcu grace period because the trampoline's image cannot be freed while the old bpf-tcp-cc is still running. * [PATCH v3 bpf-next 0/9] BPF TCP header options @ 2020-07-30 20:56 Martin KaFai Lau 2020-07-30 20:57 ` [PATCH v3 bpf-next 1/9] tcp: Use a struct to represent a saved_syn Martin KaFai Lau ` (8 more replies) 0 siblings, 9 replies; 17+ messages in thread From: Martin KaFai Lau @ 2020-07-30 20:56 UTC (permalink / raw TCP-BPF allows BPF programs to read and write to many fields of data structures (tcp_sock) maintained by the TCP stack via a mirror structure bpf_sock_ops. It also provides access to other internal TCP variables via indirect bpf_getsockopt() and bpf_setsockopt() helper functions. * [PATCH v3 bpf-next 0/9] BPF TCP header options @ 2020-07-30 20:56 Martin KaFai Lau 2020-07-30 20:57 ` [PATCH v3 bpf-next 1/9] tcp: Use a struct to represent a saved_syn Martin KaFai Lau ` (8 more replies) 0 siblings, 9 replies; 17+ messages in thread From: Martin KaFai Lau @ 2020-07-30 20:56 UTC (permalink / raw * [PATCH v3 bpf-next 0/9] BPF TCP header options @ 2020-07-30 20:56 Martin KaFai Lau 2020-07-30 20:57 ` [PATCH v3 bpf-next 1/9] tcp: Use a struct to represent a saved_syn Martin KaFai Lau ` (8 more replies) 0 siblings, 9 replies; 17+ messages in thread From: Martin KaFai Lau @ 2020-07-30 20:56 UTC (permalink / raw May 26, 2020 · bpf: pass sk struct to tcp_parse_options () This is necessary for calling TCP-BPF hook since skb->sk is not always set. We can simplify tcp_parse_options () by removing the net namespace struct from the argument list. However, it is also called with timewait sock in tcp_timewait_state_process (). This section has been extracted from the tcpdump man page and it describes the syntax of BPF filters you can specify using the -f flag. The expression consists of one or more primitives. Primitives usually consist of an id (name or number) preceded by one or more qualifiers. There are three different kinds of qualifier: type1: tcp 127.0.0.1/32 80 -> "foo" 2: tcp 127.0.0.0/24 80 -> "bar". The first binding should be matched before the second one. We need to encode this in the BPF somehow. One idea is to generate some code that executes the bindings in order of specificity, a technique we've used to great effect in l4drop:the time works fine for meand using the clamp TCP-BPF program. However, the number of packet retransmitted is quite different. It is zero when using the TCP-BPF program for most of the experiments. As a result, the 99% Latencies are about half of baseline when running the TCP-BPF program (except for the last experiment where the retransmissions are the sameMessage ID: [email protected] (mailing list archive)State: Superseded: Delegated to: BPF: Headers: show* [PATCH v3 bpf-next 0/9] BPF TCP header options @ 2020-07-30 20:56 Martin KaFai Lau 2020-07-30 20:57 ` [PATCH v3 bpf-next 1/9] tcp: Use a struct to represent a saved_syn Martin KaFai Lau ` (8 more replies) 0 siblings, 9 replies; 17+ messages in thread From: Martin KaFai Lau @ 2020-07-30 20:56 UTC (permalink / raw Primitives Primitives are references to fields in a network protocol header, such as host, port, or TCP port. The BPF syntax consists of one or more primitives, which usually consist of an ID, typically a name or number, which is preceded by one or more qualifiers. Type qualifiers3 hours ago · Joanne Koong April 2, 2022, 1:58 a.m. UTC. From: Joanne Koong <[email protected]> Such an exposure in BPF is thus required to be able to differentiate plain TCP sockets from MPTCP subflow sockets in BPF_PROG_TYPE_SOCK_OPS programs. The choice has been made to silently pass the case when CONFIG_MPTCP is unset by defaulting is_mptcp to 0 in order to make BPF independent of the MPTCP configuration. Message ID: [email protected] (mailing list archive)State: Accepted: Delegated to: BPF: Headers: showMessage ID: [email protected] (mailing list archive)State: Superseded: Delegated to: BPF: Headers: show* [PATCH v3 bpf-next 0/9] BPF TCP header options @ 2020-07-30 20:56 Martin KaFai Lau 2020-07-30 20:57 ` [PATCH v3 bpf-next 1/9] tcp: Use a struct to represent a saved_syn Martin KaFai Lau ` (8 more replies) 0 siblings, 9 replies; 17+ messages in thread From: Martin KaFai Lau @ 2020-07-30 20:56 UTC (permalink / raw Mar 31, 2022 · BPF Iterator: Retrieving Kernel Data With Flexibility and Efficiency. The BPF iterator enables high-performance, in-kernel data retrieval and aggregation. In this blog post, we talk about the motivation behind developing the bpf iterator tool and using it to retrieve kernel data into user space flexibly and efficiently. Such an exposure in BPF is thus required to be able to differentiate plain TCP sockets from MPTCP subflow sockets in BPF_PROG_TYPE_SOCK_OPS programs. The choice has been made to silently pass the case when CONFIG_MPTCP is unset by defaulting is_mptcp to 0 in order to make BPF independent of the MPTCP configuration. Primitives Primitives are references to fields in a network protocol header, such as host, port, or TCP port. The BPF syntax consists of one or more primitives, which usually consist of an ID, typically a name or number, which is preceded by one or more qualifiers. Type qualifiersTo transmit the frames, the new mode instantiates a page_pool structure in bpf_prog_run() and initialises the pages to contain XDP frames with the data passed in by userspace. These frames can then be handled as though they came from the hardware XDP path, and the existing page_pool code takes care of returning and recycling them. zenoah performance parts -fc