| Message ID | 20220602011915.264431-1-shaozhengchao@huawei.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | BPF |
| Headers | show |
| Series | [v5,bpf-next] samples/bpf: check detach prog exist or not in xdp_fwd | expand |
Zhengchao Shao <shaozhengchao@huawei.com> writes: > Before detach the prog, we should check detach prog exist or not. > > Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com> You missed one 'return errno', see below: > --- > samples/bpf/xdp_fwd_user.c | 55 +++++++++++++++++++++++++++++++++----- > 1 file changed, 49 insertions(+), 6 deletions(-) > > diff --git a/samples/bpf/xdp_fwd_user.c b/samples/bpf/xdp_fwd_user.c > index 1828487bae9a..d321e6aa9364 100644 > --- a/samples/bpf/xdp_fwd_user.c > +++ b/samples/bpf/xdp_fwd_user.c > @@ -47,17 +47,60 @@ static int do_attach(int idx, int prog_fd, int map_fd, const char *name) > return err; > } > > -static int do_detach(int idx, const char *name) > +static int do_detach(int ifindex, const char *ifname, const char *app_name) > { > - int err; > + LIBBPF_OPTS(bpf_xdp_attach_opts, opts); > + struct bpf_prog_info prog_info = {}; > + char prog_name[BPF_OBJ_NAME_LEN]; > + __u32 info_len, curr_prog_id; > + int prog_fd; > + int err = 1; > + > + if (bpf_xdp_query_id(ifindex, xdp_flags, &curr_prog_id)) { > + printf("ERROR: bpf_xdp_query_id failed (%s)\n", > + strerror(errno)); > + return err; > + } > > - err = bpf_xdp_detach(idx, xdp_flags, NULL); > - if (err < 0) > - printf("ERROR: failed to detach program from %s\n", name); > + if (!curr_prog_id) { > + printf("ERROR: flags(0x%x) xdp prog is not attached to %s\n", > + xdp_flags, ifname); > + return err; > + } > > + info_len = sizeof(prog_info); > + prog_fd = bpf_prog_get_fd_by_id(curr_prog_id); > + if (prog_fd < 0) { > + printf("ERROR: bpf_prog_get_fd_by_id failed (%s)\n", > + strerror(errno)); > + return errno; This should just be 'return prog_fd' to propagate the error... -Toke
-----邮件原件----- 发件人: Toke Høiland-Jørgensen [mailto:toke@kernel.org] 发送时间: 2022年6月2日 16:55 收件人: shaozhengchao <shaozhengchao@huawei.com>; bpf@vger.kernel.org; netdev@vger.kernel.org; linux-kernel@vger.kernel.org; ast@kernel.org; daniel@iogearbox.net; davem@davemloft.net; kuba@kernel.org; hawk@kernel.org; john.fastabend@gmail.com; andrii@kernel.org; kafai@fb.com; songliubraving@fb.com; yhs@fb.com; kpsingh@kernel.org 抄送: weiyongjun (A) <weiyongjun1@huawei.com>; shaozhengchao <shaozhengchao@huawei.com>; yuehaibing <yuehaibing@huawei.com> 主题: Re: [PATCH v5,bpf-next] samples/bpf: check detach prog exist or not in xdp_fwd Zhengchao Shao <shaozhengchao@huawei.com> writes: > Before detach the prog, we should check detach prog exist or not. > > Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com> You missed one 'return errno', see below: > --- > samples/bpf/xdp_fwd_user.c | 55 > +++++++++++++++++++++++++++++++++----- > 1 file changed, 49 insertions(+), 6 deletions(-) > > diff --git a/samples/bpf/xdp_fwd_user.c b/samples/bpf/xdp_fwd_user.c > index 1828487bae9a..d321e6aa9364 100644 > --- a/samples/bpf/xdp_fwd_user.c > +++ b/samples/bpf/xdp_fwd_user.c > @@ -47,17 +47,60 @@ static int do_attach(int idx, int prog_fd, int map_fd, const char *name) > return err; > } > > -static int do_detach(int idx, const char *name) > +static int do_detach(int ifindex, const char *ifname, const char > +*app_name) > { > - int err; > + LIBBPF_OPTS(bpf_xdp_attach_opts, opts); > + struct bpf_prog_info prog_info = {}; > + char prog_name[BPF_OBJ_NAME_LEN]; > + __u32 info_len, curr_prog_id; > + int prog_fd; > + int err = 1; > + > + if (bpf_xdp_query_id(ifindex, xdp_flags, &curr_prog_id)) { > + printf("ERROR: bpf_xdp_query_id failed (%s)\n", > + strerror(errno)); > + return err; > + } > > - err = bpf_xdp_detach(idx, xdp_flags, NULL); > - if (err < 0) > - printf("ERROR: failed to detach program from %s\n", name); > + if (!curr_prog_id) { > + printf("ERROR: flags(0x%x) xdp prog is not attached to %s\n", > + xdp_flags, ifname); > + return err; > + } > > + info_len = sizeof(prog_info); > + prog_fd = bpf_prog_get_fd_by_id(curr_prog_id); > + if (prog_fd < 0) { > + printf("ERROR: bpf_prog_get_fd_by_id failed (%s)\n", > + strerror(errno)); > + return errno; This should just be ' return prog_fd ' to propagate the error... -Toke Hi Toke: Use 'return prog_fd' instead of 'return errno' first. And Which position missed one 'return errno'? -Zhengchao Shao
shaozhengchao <shaozhengchao@huawei.com> writes: > -----邮件原件----- > 发件人: Toke Høiland-Jørgensen [mailto:toke@kernel.org] > 发送时间: 2022年6月2日 16:55 > 收件人: shaozhengchao <shaozhengchao@huawei.com>; bpf@vger.kernel.org; netdev@vger.kernel.org; linux-kernel@vger.kernel.org; ast@kernel.org; daniel@iogearbox.net; davem@davemloft.net; kuba@kernel.org; hawk@kernel.org; john.fastabend@gmail.com; andrii@kernel.org; kafai@fb.com; songliubraving@fb.com; yhs@fb.com; kpsingh@kernel.org > 抄送: weiyongjun (A) <weiyongjun1@huawei.com>; shaozhengchao <shaozhengchao@huawei.com>; yuehaibing <yuehaibing@huawei.com> > 主题: Re: [PATCH v5,bpf-next] samples/bpf: check detach prog exist or not in xdp_fwd > > Zhengchao Shao <shaozhengchao@huawei.com> writes: > >> Before detach the prog, we should check detach prog exist or not. >> >> Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com> > > You missed one 'return errno', see below: > >> --- >> samples/bpf/xdp_fwd_user.c | 55 >> +++++++++++++++++++++++++++++++++----- >> 1 file changed, 49 insertions(+), 6 deletions(-) >> >> diff --git a/samples/bpf/xdp_fwd_user.c b/samples/bpf/xdp_fwd_user.c >> index 1828487bae9a..d321e6aa9364 100644 >> --- a/samples/bpf/xdp_fwd_user.c >> +++ b/samples/bpf/xdp_fwd_user.c >> @@ -47,17 +47,60 @@ static int do_attach(int idx, int prog_fd, int map_fd, const char *name) >> return err; >> } >> >> -static int do_detach(int idx, const char *name) >> +static int do_detach(int ifindex, const char *ifname, const char >> +*app_name) >> { >> - int err; >> + LIBBPF_OPTS(bpf_xdp_attach_opts, opts); >> + struct bpf_prog_info prog_info = {}; >> + char prog_name[BPF_OBJ_NAME_LEN]; >> + __u32 info_len, curr_prog_id; >> + int prog_fd; >> + int err = 1; >> + >> + if (bpf_xdp_query_id(ifindex, xdp_flags, &curr_prog_id)) { >> + printf("ERROR: bpf_xdp_query_id failed (%s)\n", >> + strerror(errno)); >> + return err; >> + } >> >> - err = bpf_xdp_detach(idx, xdp_flags, NULL); >> - if (err < 0) >> - printf("ERROR: failed to detach program from %s\n", name); >> + if (!curr_prog_id) { >> + printf("ERROR: flags(0x%x) xdp prog is not attached to %s\n", >> + xdp_flags, ifname); >> + return err; >> + } >> >> + info_len = sizeof(prog_info); >> + prog_fd = bpf_prog_get_fd_by_id(curr_prog_id); >> + if (prog_fd < 0) { >> + printf("ERROR: bpf_prog_get_fd_by_id failed (%s)\n", >> + strerror(errno)); >> + return errno; > > This should just be ' return prog_fd ' to propagate the error... > > -Toke > > > Hi Toke: > Use 'return prog_fd' instead of 'return errno' first. And Which > position missed one 'return errno'? Ah, no, that's the one I was talking about; I meant "missed one" as in "missed removing one of them", not "a return errno was missing but should be there"; so just changing that one to 'return prog_fd' should and I think we should be good :) -Toke
diff --git a/samples/bpf/xdp_fwd_user.c b/samples/bpf/xdp_fwd_user.c index 1828487bae9a..d321e6aa9364 100644 --- a/samples/bpf/xdp_fwd_user.c +++ b/samples/bpf/xdp_fwd_user.c @@ -47,17 +47,60 @@ static int do_attach(int idx, int prog_fd, int map_fd, const char *name) return err; } -static int do_detach(int idx, const char *name) +static int do_detach(int ifindex, const char *ifname, const char *app_name) { - int err; + LIBBPF_OPTS(bpf_xdp_attach_opts, opts); + struct bpf_prog_info prog_info = {}; + char prog_name[BPF_OBJ_NAME_LEN]; + __u32 info_len, curr_prog_id; + int prog_fd; + int err = 1; + + if (bpf_xdp_query_id(ifindex, xdp_flags, &curr_prog_id)) { + printf("ERROR: bpf_xdp_query_id failed (%s)\n", + strerror(errno)); + return err; + } - err = bpf_xdp_detach(idx, xdp_flags, NULL); - if (err < 0) - printf("ERROR: failed to detach program from %s\n", name); + if (!curr_prog_id) { + printf("ERROR: flags(0x%x) xdp prog is not attached to %s\n", + xdp_flags, ifname); + return err; + } + info_len = sizeof(prog_info); + prog_fd = bpf_prog_get_fd_by_id(curr_prog_id); + if (prog_fd < 0) { + printf("ERROR: bpf_prog_get_fd_by_id failed (%s)\n", + strerror(errno)); + return errno; + } + + err = bpf_obj_get_info_by_fd(prog_fd, &prog_info, &info_len); + if (err) { + printf("ERROR: bpf_obj_get_info_by_fd failed (%s)\n", + strerror(errno)); + goto close_out; + } + snprintf(prog_name, sizeof(prog_name), "%s_prog", app_name); + prog_name[BPF_OBJ_NAME_LEN - 1] = '\0'; + + if (strcmp(prog_info.name, prog_name)) { + printf("ERROR: %s isn't attached to %s\n", app_name, ifname); + err = 1; + goto close_out; + } + + opts.old_prog_fd = prog_fd; + err = bpf_xdp_detach(ifindex, xdp_flags, &opts); + if (err < 0) + printf("ERROR: failed to detach program from %s (%s)\n", + ifname, strerror(errno)); /* TODO: Remember to cleanup map, when adding use of shared map * bpf_map_delete_elem((map_fd, &idx); */ +close_out: + close(prog_fd); return err; } @@ -169,7 +212,7 @@ int main(int argc, char **argv) return 1; } if (!attach) { - err = do_detach(idx, argv[i]); + err = do_detach(idx, argv[i], prog_name); if (err) ret = err; } else {
Before detach the prog, we should check detach prog exist or not. Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com> --- samples/bpf/xdp_fwd_user.c | 55 +++++++++++++++++++++++++++++++++----- 1 file changed, 49 insertions(+), 6 deletions(-)