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Commit 6b1d90b7 authored by Daniel Borkmann's avatar Daniel Borkmann
Browse files

Merge branch 'bpf-uapi-doc-fixes' 



Quentin Monnet says:

====================
Another round of fixes for the doc in the BPF UAPI header, which can be
turned into a manual page. First patch is the most important, as it fixes
parsing for the bpf_strtoul() helper doc. Following patches are formatting
fixes (nitpicks, mostly). The last one updates the copy of the header,
located under tools/.
====================

Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parents 98583812 c1fe1e70

include/uapi/linux/bpf.h

+75 −70
Original line number Diff line number Diff line
@@ -629,7 +629,7 @@ union bpf_attr { 
 * 		**BPF_F_INVALIDATE_HASH** (set *skb*\ **->hash**, *skb*\

 * 		**->swhash** and *skb*\ **->l4hash** to 0).

 *

 * 		A call to this helper is susceptible to change the underlaying

 * 		A call to this helper is susceptible to change the underlying

 * 		packet buffer. Therefore, at load time, all checks on pointers

 * 		previously done by the verifier are invalidated and must be

 * 		performed again, if the helper is used in combination with
@@ -654,7 +654,7 @@ union bpf_attr { 
 * 		flexibility and can handle sizes larger than 2 or 4 for the

 * 		checksum to update.

 *

 * 		A call to this helper is susceptible to change the underlaying

 * 		A call to this helper is susceptible to change the underlying

 * 		packet buffer. Therefore, at load time, all checks on pointers

 * 		previously done by the verifier are invalidated and must be

 * 		performed again, if the helper is used in combination with
@@ -686,7 +686,7 @@ union bpf_attr { 
 * 		flexibility and can handle sizes larger than 2 or 4 for the

 * 		checksum to update.

 *

 * 		A call to this helper is susceptible to change the underlaying

 * 		A call to this helper is susceptible to change the underlying

 * 		packet buffer. Therefore, at load time, all checks on pointers

 * 		previously done by the verifier are invalidated and must be

 * 		performed again, if the helper is used in combination with
@@ -741,7 +741,7 @@ union bpf_attr { 
 * 		efficient, but it is handled through an action code where the

 * 		redirection happens only after the eBPF program has returned.

 *

 * 		A call to this helper is susceptible to change the underlaying

 * 		A call to this helper is susceptible to change the underlying

 * 		packet buffer. Therefore, at load time, all checks on pointers

 * 		previously done by the verifier are invalidated and must be

 * 		performed again, if the helper is used in combination with
@@ -806,7 +806,7 @@ union bpf_attr { 
 * 		**ETH_P_8021Q** and **ETH_P_8021AD**, it is considered to

 * 		be **ETH_P_8021Q**.

 *

 * 		A call to this helper is susceptible to change the underlaying

 * 		A call to this helper is susceptible to change the underlying

 * 		packet buffer. Therefore, at load time, all checks on pointers

 * 		previously done by the verifier are invalidated and must be

 * 		performed again, if the helper is used in combination with
@@ -818,7 +818,7 @@ union bpf_attr { 
 * 	Description

 * 		Pop a VLAN header from the packet associated to *skb*.

 *

 * 		A call to this helper is susceptible to change the underlaying

 * 		A call to this helper is susceptible to change the underlying

 * 		packet buffer. Therefore, at load time, all checks on pointers

 * 		previously done by the verifier are invalidated and must be

 * 		performed again, if the helper is used in combination with
@@ -1168,7 +1168,7 @@ union bpf_attr { 
 * 		All values for *flags* are reserved for future usage, and must

 * 		be left at zero.

 *

 * 		A call to this helper is susceptible to change the underlaying

 * 		A call to this helper is susceptible to change the underlying

 * 		packet buffer. Therefore, at load time, all checks on pointers

 * 		previously done by the verifier are invalidated and must be

 * 		performed again, if the helper is used in combination with
@@ -1281,7 +1281,7 @@ union bpf_attr { 
 * 		implicitly linearizes, unclones and drops offloads from the

 * 		*skb*.

 *

 * 		A call to this helper is susceptible to change the underlaying

 * 		A call to this helper is susceptible to change the underlying

 * 		packet buffer. Therefore, at load time, all checks on pointers

 * 		previously done by the verifier are invalidated and must be

 * 		performed again, if the helper is used in combination with
@@ -1317,7 +1317,7 @@ union bpf_attr { 
 * 		**bpf_skb_pull_data()** to effectively unclone the *skb* from

 * 		the very beginning in case it is indeed cloned.

 *

 * 		A call to this helper is susceptible to change the underlaying

 * 		A call to this helper is susceptible to change the underlying

 * 		packet buffer. Therefore, at load time, all checks on pointers

 * 		previously done by the verifier are invalidated and must be

 * 		performed again, if the helper is used in combination with
@@ -1369,7 +1369,7 @@ union bpf_attr { 
 * 		All values for *flags* are reserved for future usage, and must

 * 		be left at zero.

 *

 * 		A call to this helper is susceptible to change the underlaying

 * 		A call to this helper is susceptible to change the underlying

 * 		packet buffer. Therefore, at load time, all checks on pointers

 * 		previously done by the verifier are invalidated and must be

 * 		performed again, if the helper is used in combination with
@@ -1384,7 +1384,7 @@ union bpf_attr { 
 * 		can be used to prepare the packet for pushing or popping

 * 		headers.

 *

 * 		A call to this helper is susceptible to change the underlaying

 * 		A call to this helper is susceptible to change the underlying

 * 		packet buffer. Therefore, at load time, all checks on pointers

 * 		previously done by the verifier are invalidated and must be

 * 		performed again, if the helper is used in combination with
@@ -1518,20 +1518,20 @@ union bpf_attr { 
 *		* **BPF_F_ADJ_ROOM_FIXED_GSO**: Do not adjust gso_size.

 *		  Adjusting mss in this way is not allowed for datagrams.

 *

 *		* **BPF_F_ADJ_ROOM_ENCAP_L3_IPV4 **:

 *		* **BPF_F_ADJ_ROOM_ENCAP_L3_IPV6 **:

 *		* **BPF_F_ADJ_ROOM_ENCAP_L3_IPV4**,

 *		  **BPF_F_ADJ_ROOM_ENCAP_L3_IPV6**:

 *		  Any new space is reserved to hold a tunnel header.

 *		  Configure skb offsets and other fields accordingly.

 *

 *		* **BPF_F_ADJ_ROOM_ENCAP_L4_GRE **:

 *		* **BPF_F_ADJ_ROOM_ENCAP_L4_UDP **:

 *		* **BPF_F_ADJ_ROOM_ENCAP_L4_GRE**,

 *		  **BPF_F_ADJ_ROOM_ENCAP_L4_UDP**:

 *		  Use with ENCAP_L3 flags to further specify the tunnel type.

 *

 *		* **BPF_F_ADJ_ROOM_ENCAP_L2(len) **:

 *		* **BPF_F_ADJ_ROOM_ENCAP_L2**\ (*len*):

 *		  Use with ENCAP_L3/L4 flags to further specify the tunnel

 *		  type; **len** is the length of the inner MAC header.

 *		  type; *len* is the length of the inner MAC header.

 *

 * 		A call to this helper is susceptible to change the underlaying

 * 		A call to this helper is susceptible to change the underlying

 * 		packet buffer. Therefore, at load time, all checks on pointers

 * 		previously done by the verifier are invalidated and must be

 * 		performed again, if the helper is used in combination with
@@ -1610,7 +1610,7 @@ union bpf_attr { 
 * 		more flexibility as the user is free to store whatever meta

 * 		data they need.

 *

 * 		A call to this helper is susceptible to change the underlaying

 * 		A call to this helper is susceptible to change the underlying

 * 		packet buffer. Therefore, at load time, all checks on pointers

 * 		previously done by the verifier are invalidated and must be

 * 		performed again, if the helper is used in combination with
@@ -1852,7 +1852,7 @@ union bpf_attr { 
 * 		copied if necessary (i.e. if data was not linear and if start

 * 		and end pointers do not point to the same chunk).

 *

 * 		A call to this helper is susceptible to change the underlaying

 * 		A call to this helper is susceptible to change the underlying

 * 		packet buffer. Therefore, at load time, all checks on pointers

 * 		previously done by the verifier are invalidated and must be

 * 		performed again, if the helper is used in combination with
@@ -1886,7 +1886,7 @@ union bpf_attr { 
 * 		only possible to shrink the packet as of this writing,

 * 		therefore *delta* must be a negative integer.

 *

 * 		A call to this helper is susceptible to change the underlaying

 * 		A call to this helper is susceptible to change the underlying

 * 		packet buffer. Therefore, at load time, all checks on pointers

 * 		previously done by the verifier are invalidated and must be

 * 		performed again, if the helper is used in combination with
@@ -2061,18 +2061,18 @@ union bpf_attr { 
 *		**BPF_LWT_ENCAP_IP**

 *			IP encapsulation (GRE/GUE/IPIP/etc). The outer header

 *			must be IPv4 or IPv6, followed by zero or more

 *			additional headers, up to LWT_BPF_MAX_HEADROOM total

 *			bytes in all prepended headers. Please note that

 *			if skb_is_gso(skb) is true, no more than two headers

 *			can be prepended, and the inner header, if present,

 *			should be either GRE or UDP/GUE.

 *

 *		BPF_LWT_ENCAP_SEG6*** types can be called by bpf programs of

 *		type BPF_PROG_TYPE_LWT_IN; BPF_LWT_ENCAP_IP type can be called

 *		by bpf programs of types BPF_PROG_TYPE_LWT_IN and

 *		BPF_PROG_TYPE_LWT_XMIT.

 *

 * 		A call to this helper is susceptible to change the underlaying

 *			additional headers, up to **LWT_BPF_MAX_HEADROOM**

 *			total bytes in all prepended headers. Please note that

 *			if **skb_is_gso**\ (*skb*) is true, no more than two

 *			headers can be prepended, and the inner header, if

 *			present, should be either GRE or UDP/GUE.

 *

 *		**BPF_LWT_ENCAP_SEG6**\ \* types can be called by BPF programs

 *		of type **BPF_PROG_TYPE_LWT_IN**; **BPF_LWT_ENCAP_IP** type can

 *		be called by bpf programs of types **BPF_PROG_TYPE_LWT_IN** and

 *		**BPF_PROG_TYPE_LWT_XMIT**.

 *

 * 		A call to this helper is susceptible to change the underlying

 * 		packet buffer. Therefore, at load time, all checks on pointers

 * 		previously done by the verifier are invalidated and must be

 * 		performed again, if the helper is used in combination with
@@ -2087,7 +2087,7 @@ union bpf_attr { 
 *		inside the outermost IPv6 Segment Routing Header can be

 *		modified through this helper.

 *

 * 		A call to this helper is susceptible to change the underlaying

 * 		A call to this helper is susceptible to change the underlying

 * 		packet buffer. Therefore, at load time, all checks on pointers

 * 		previously done by the verifier are invalidated and must be

 * 		performed again, if the helper is used in combination with
@@ -2103,7 +2103,7 @@ union bpf_attr { 
 *		after the segments are accepted. *delta* can be as well

 *		positive (growing) as negative (shrinking).

 *

 * 		A call to this helper is susceptible to change the underlaying

 * 		A call to this helper is susceptible to change the underlying

 * 		packet buffer. Therefore, at load time, all checks on pointers

 * 		previously done by the verifier are invalidated and must be

 * 		performed again, if the helper is used in combination with
@@ -2126,13 +2126,13 @@ union bpf_attr { 
 *			Type of *param*: **int**.

 *		**SEG6_LOCAL_ACTION_END_B6**

 *			End.B6 action: Endpoint bound to an SRv6 policy.

 *			Type of param: **struct ipv6_sr_hdr**.

 *			Type of *param*: **struct ipv6_sr_hdr**.

 *		**SEG6_LOCAL_ACTION_END_B6_ENCAP**

 *			End.B6.Encap action: Endpoint bound to an SRv6

 *			encapsulation policy.

 *			Type of param: **struct ipv6_sr_hdr**.

 *			Type of *param*: **struct ipv6_sr_hdr**.

 *

 * 		A call to this helper is susceptible to change the underlaying

 * 		A call to this helper is susceptible to change the underlying

 * 		packet buffer. Therefore, at load time, all checks on pointers

 * 		previously done by the verifier are invalidated and must be

 * 		performed again, if the helper is used in combination with
@@ -2285,7 +2285,8 @@ union bpf_attr { 
 *	Return

 *		Pointer to **struct bpf_sock**, or **NULL** in case of failure.

 *		For sockets with reuseport option, the **struct bpf_sock**

 *		result is from **reuse->socks**\ [] using the hash of the tuple.

 *		result is from *reuse*\ **->socks**\ [] using the hash of the

 *		tuple.

 *

 * struct bpf_sock *bpf_sk_lookup_udp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags)

 *	Description
@@ -2321,7 +2322,8 @@ union bpf_attr { 
 *	Return

 *		Pointer to **struct bpf_sock**, or **NULL** in case of failure.

 *		For sockets with reuseport option, the **struct bpf_sock**

 *		result is from **reuse->socks**\ [] using the hash of the tuple.

 *		result is from *reuse*\ **->socks**\ [] using the hash of the

 *		tuple.

 *

 * int bpf_sk_release(struct bpf_sock *sock)

 *	Description
@@ -2490,31 +2492,34 @@ union bpf_attr { 
 *		network namespace *netns*. The return value must be checked,

 *		and if non-**NULL**, released via **bpf_sk_release**\ ().

 *

 *		This function is identical to bpf_sk_lookup_tcp, except that it

 *		also returns timewait or request sockets. Use bpf_sk_fullsock

 *		or bpf_tcp_socket to access the full structure.

 *		This function is identical to **bpf_sk_lookup_tcp**\ (), except

 *		that it also returns timewait or request sockets. Use

 *		**bpf_sk_fullsock**\ () or **bpf_tcp_sock**\ () to access the

 *		full structure.

 *

 *		This helper is available only if the kernel was compiled with

 *		**CONFIG_NET** configuration option.

 *	Return

 *		Pointer to **struct bpf_sock**, or **NULL** in case of failure.

 *		For sockets with reuseport option, the **struct bpf_sock**

 *		result is from **reuse->socks**\ [] using the hash of the tuple.

 *		result is from *reuse*\ **->socks**\ [] using the hash of the

 *		tuple.

 *

 * int bpf_tcp_check_syncookie(struct bpf_sock *sk, void *iph, u32 iph_len, struct tcphdr *th, u32 th_len)

 * 	Description

 * 		Check whether iph and th contain a valid SYN cookie ACK for

 * 		the listening socket in sk.

 * 		Check whether *iph* and *th* contain a valid SYN cookie ACK for

 * 		the listening socket in *sk*.

 *

 * 		iph points to the start of the IPv4 or IPv6 header, while

 * 		iph_len contains sizeof(struct iphdr) or sizeof(struct ip6hdr).

 * 		*iph* points to the start of the IPv4 or IPv6 header, while

 * 		*iph_len* contains **sizeof**\ (**struct iphdr**) or

 * 		**sizeof**\ (**struct ip6hdr**).

 *

 * 		th points to the start of the TCP header, while th_len contains

 * 		sizeof(struct tcphdr).

 * 		*th* points to the start of the TCP header, while *th_len*

 * 		contains **sizeof**\ (**struct tcphdr**).

 *

 * 	Return

 * 		0 if iph and th are a valid SYN cookie ACK, or a negative error

 * 		otherwise.

 * 		0 if *iph* and *th* are a valid SYN cookie ACK, or a negative

 * 		error otherwise.

 *

 * int bpf_sysctl_get_name(struct bpf_sysctl *ctx, char *buf, size_t buf_len, u64 flags)

 *	Description
@@ -2592,17 +2597,17 @@ union bpf_attr { 
 *		and save the result in *res*.

 *

 *		The string may begin with an arbitrary amount of white space

 *		(as determined by isspace(3)) followed by a single optional '-'

 *		sign.

 *		(as determined by **isspace**\ (3)) followed by a single

 *		optional '**-**' sign.

 *

 *		Five least significant bits of *flags* encode base, other bits

 *		are currently unused.

 *

 *		Base must be either 8, 10, 16 or 0 to detect it automatically

 *		similar to user space strtol(3).

 *		similar to user space **strtol**\ (3).

 *	Return

 *		Number of characters consumed on success. Must be positive but

 *		no more than buf_len.

 *		no more than *buf_len*.

 *

 *		**-EINVAL** if no valid digits were found or unsupported base

 *		was provided.
@@ -2616,16 +2621,16 @@ union bpf_attr { 
 *		given base and save the result in *res*.

 *

 *		The string may begin with an arbitrary amount of white space

 *		(as determined by isspace(3)).

 *		(as determined by **isspace**\ (3)).

 *

 *		Five least significant bits of *flags* encode base, other bits

 *		are currently unused.

 *

 *		Base must be either 8, 10, 16 or 0 to detect it automatically

 *		similar to user space strtoul(3).

 *		similar to user space **strtoul**\ (3).

 *	Return

 *		Number of characters consumed on success. Must be positive but

 *		no more than buf_len.

 *		no more than *buf_len*.

 *

 *		**-EINVAL** if no valid digits were found or unsupported base

 *		was provided.
@@ -2634,26 +2639,26 @@ union bpf_attr { 
 *

 * void *bpf_sk_storage_get(struct bpf_map *map, struct bpf_sock *sk, void *value, u64 flags)

 *	Description

 *		Get a bpf-local-storage from a sk.

 *		Get a bpf-local-storage from a *sk*.

 *

 *		Logically, it could be thought of getting the value from

 *		a *map* with *sk* as the **key**.  From this

 *		perspective,  the usage is not much different from

 *		**bpf_map_lookup_elem(map, &sk)** except this

 *		helper enforces the key must be a **bpf_fullsock()**

 *		and the map must be a BPF_MAP_TYPE_SK_STORAGE also.

 *		**bpf_map_lookup_elem**\ (*map*, **&**\ *sk*) except this

 *		helper enforces the key must be a full socket and the map must

 *		be a **BPF_MAP_TYPE_SK_STORAGE** also.

 *

 *		Underneath, the value is stored locally at *sk* instead of

 *		the map.  The *map* is used as the bpf-local-storage **type**.

 *		The bpf-local-storage **type** (i.e. the *map*) is searched

 *		against all bpf-local-storages residing at sk.

 *		the *map*.  The *map* is used as the bpf-local-storage

 *		"type". The bpf-local-storage "type" (i.e. the *map*) is

 *		searched against all bpf-local-storages residing at *sk*.

 *

 *		An optional *flags* (BPF_SK_STORAGE_GET_F_CREATE) can be

 *		An optional *flags* (**BPF_SK_STORAGE_GET_F_CREATE**) can be

 *		used such that a new bpf-local-storage will be

 *		created if one does not exist.  *value* can be used

 *		together with BPF_SK_STORAGE_GET_F_CREATE to specify

 *		together with **BPF_SK_STORAGE_GET_F_CREATE** to specify

 *		the initial value of a bpf-local-storage.  If *value* is

 *		NULL, the new bpf-local-storage will be zero initialized.

 *		**NULL**, the new bpf-local-storage will be zero initialized.

 *	Return

 *		A bpf-local-storage pointer is returned on success.

 *
@@ -2662,7 +2667,7 @@ union bpf_attr { 
 *

 * int bpf_sk_storage_delete(struct bpf_map *map, struct bpf_sock *sk)

 *	Description

 *		Delete a bpf-local-storage from a sk.

 *		Delete a bpf-local-storage from a *sk*.

 *	Return

 *		0 on success.

 *

scripts/bpf_helpers_doc.py

+4 −4
Original line number Diff line number Diff line 
#!/usr/bin/python3

# SPDX-License-Identifier: GPL-2.0-only

#

# Copyright (C) 2018 Netronome Systems, Inc.

# Copyright (C) 2018-2019 Netronome Systems, Inc.



# In case user attempts to run with Python 2.

from __future__ import print_function
@@ -39,7 +39,7 @@ class Helper(object): 
        Break down helper function protocol into smaller chunks: return type,

        name, distincts arguments.

        """

        arg_re = re.compile('((const )?(struct )?(\w+|...))( (\**)(\w+))?$')

        arg_re = re.compile('((\w+ )*?(\w+|...))( (\**)(\w+))?$')

        res = {}

        proto_re = re.compile('(.+) (\**)(\w+)\(((([^,]+)(, )?){1,5})\)$')
@@ -54,8 +54,8 @@ class Helper(object): 
            capture = arg_re.match(a)

            res['args'].append({

                'type' : capture.group(1),

                'star' : capture.group(6),

                'name' : capture.group(7)

                'star' : capture.group(5),

                'name' : capture.group(6)

            })



        return res

tools/include/uapi/linux/bpf.h

+75 −70

File changed.

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