kernel.git/tools/bpf/bpftool/net.c, branch linux-5.13.y

bpftool: Fix a clang compilation warning

2021-04-15T23:50:22Z

With clang compiler: make -j60 LLVM=1 LLVM_IAS=1 <=== compile kernel # build selftests/bpf or bpftool make -j60 -C tools/testing/selftests/bpf LLVM=1 LLVM_IAS=1 make -j60 -C tools/bpf/bpftool LLVM=1 LLVM_IAS=1 the following compilation warning showed up, net.c:160:37: warning: comparison of integers of different signs: '__u32' (aka 'unsigned int') and 'int' [-Wsign-compare] for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, len); ^~~~~~~~~~~~~~~~~ .../tools/include/uapi/linux/netlink.h:99:24: note: expanded from macro 'NLMSG_OK' (nlh)->nlmsg_len <= (len)) ~~~~~~~~~~~~~~~~ ^ ~~~ In this particular case, "len" is defined as "int" and (nlh)->nlmsg_len is "unsigned int". The macro NLMSG_OK is defined as below in uapi/linux/netlink.h. #define NLMSG_OK(nlh,len) ((len) >= (int)sizeof(struct nlmsghdr) && \ (nlh)->nlmsg_len >= sizeof(struct nlmsghdr) && \ (nlh)->nlmsg_len <= (len)) The clang compiler complains the comparision "(nlh)->nlmsg_len <= (len))", but in bpftool/net.c, it is already ensured that "len > 0" must be true. So theoretically the compiler could deduce that comparison of "(nlh)->nlmsg_len" and "len" is okay, but this really depends on compiler internals. Let us add an explicit type conversion (from "int" to "unsigned int") for "len" in NLMSG_OK to silence this warning right now. Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20210413153435.3029635-1-yhs@fb.com

bpftool: Fix compilation failure for net.o with older glibc

2021-01-06T23:27:38Z

For older glibc ~2.17, #include'ing both linux/if.h and net/if.h fails due to complaints about redefinition of interface flags: CC net.o In file included from net.c:13:0: /usr/include/linux/if.h:71:2: error: redeclaration of enumerator ‘IFF_UP’ IFF_UP = 1<<0, /* sysfs */ ^ /usr/include/net/if.h:44:5: note: previous definition of ‘IFF_UP’ was here IFF_UP = 0x1, /* Interface is up. */ The issue was fixed in kernel headers in [1], but since compilation of net.c picks up system headers the problem can recur. Dropping #include resolves the issue and it is not needed for compilation anyhow. [1] https://lore.kernel.org/netdev/1461512707-23058-1-git-send-email-mikko.rapeli__34748.27880641$1462831734$gmane$org@iki.fi/ Fixes: f6f3bac08ff9 ("tools/bpf: bpftool: add net support") Signed-off-by: Alan Maguire Signed-off-by: Andrii Nakryiko Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/1609948746-15369-1-git-send-email-alan.maguire@oracle.com

tools, bpftool: Add missing close before bpftool net attach exit

2020-11-13T14:59:13Z

progfd is created by prog_parse_fd() in do_attach() and before the latter returns in case of success, the file descriptor should be closed. Fixes: 04949ccc273e ("tools: bpftool: add net attach command to attach XDP on interface") Signed-off-by: Wang Hai Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20201113115152.53178-1-wanghai38@huawei.com

tools/bpftool: Remove libbpf_internal.h usage in bpftool

2020-08-19T01:38:25Z

Most netlink-related functions were unique to bpftool usage, so I moved them into net.c. Few functions are still used by both bpftool and libbpf itself internally, so I've copy-pasted them (libbpf_nl_get_link, libbpf_netlink_open). It's a bit of duplication of code, but better separation of libbpf as a library with public API and bpftool, relying on unexposed functions in libbpf. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200819013607.3607269-3-andriin@fb.com

tools, bpftool: Clean subcommand help messages

2020-06-01T21:38:18Z

This is a clean-up for the formatting of the do_help functions for bpftool's subcommands. The following fixes are included: - Do not use argv[-2] for "iter" help message, as the help is shown by default if no "iter" action is selected, resulting in messages looking like "./bpftool bpftool pin...". - Do not print unused HELP_SPEC_PROGRAM in help message for "bpftool link". - Andrii used argument indexing to avoid having multiple occurrences of bin_name and argv[-2] in the fprintf() for the help message, for "bpftool gen" and "bpftool link". Let's reuse this for all other help functions. We can remove up to thirty arguments for the "bpftool map" help message. - Harmonise all functions, e.g. use ending quotes-comma on a separate line. Signed-off-by: Quentin Monnet Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20200523010751.23465-1-quentin@isovalent.com Signed-off-by: Alexei Starovoitov

bpftool: Use consistent include paths for libbpf

2020-01-21T00:37:45Z

Fix bpftool to include libbpf header files with the bpf/ prefix, to be consistent with external users of the library. Also ensure that all includes of exported libbpf header files (those that are exported on 'make install' of the library) use bracketed includes instead of quoted. To make sure no new files are introduced that doesn't include the bpf/ prefix in its include, remove tools/lib/bpf from the include path entirely, and use tools/lib instead. Fixes: 6910d7d3867a ("selftests/bpf: Ensure bpf_helper_defs.h are taken from selftests dir") Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/157952560684.1683545.4765181397974997027.stgit@toke.dk

libbpf: Move non-public APIs from libbpf.h to libbpf_internal.h

2019-12-15T23:58:04Z

Few libbpf APIs are not public but currently exposed through libbpf.h to be used by bpftool. Move them to libbpf_internal.h, where intent of being non-stable and non-public is much more obvious. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20191214014341.3442258-4-andriin@fb.com

tools: bpftool: fix format string for p_err() in query_flow_dissector()

2019-08-16T05:06:46Z

The format string passed to one call to the p_err() function in query_flow_dissector() does not match the value that should be printed, resulting in some garbage integer being printed instead of strerror(errno) if /proc/self/ns/net cannot be open. Let's fix the format string. Fixes: 7f0c57fec80f ("bpftool: show flow_dissector attachment status") Signed-off-by: Quentin Monnet Reviewed-by: Jakub Kicinski Signed-off-by: Alexei Starovoitov

tools: bpftool: add net detach command to detach XDP on interface

2019-08-16T00:00:33Z

By this commit, using `bpftool net detach`, the attached XDP prog can be detached. Detaching the BPF prog will be done through libbpf 'bpf_set_link_xdp_fd' with the progfd set to -1. Acked-by: Yonghong Song Signed-off-by: Daniel T. Lee Signed-off-by: Alexei Starovoitov

tools: bpftool: add net attach command to attach XDP on interface

2019-08-16T00:00:33Z

By this commit, using `bpftool net attach`, user can attach XDP prog on interface. New type of enum 'net_attach_type' has been made, as stat ted at cover-letter, the meaning of 'attach' is, prog will be attached on interface. With 'overwrite' option at argument, attached XDP program could be replaced. Added new helper 'net_parse_dev' to parse the network device at argument. BPF prog will be attached through libbpf 'bpf_set_link_xdp_fd'. Acked-by: Yonghong Song Signed-off-by: Daniel T. Lee Signed-off-by: Alexei Starovoitov