| Message ID | 20220801132409.4147849-1-chantr4@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | d55dfe587bc0670f90564a962615723fe7749ab1 |
| Delegated to: | BPF |
| Headers | show |
| Series | [bpf-next,v3] bpftool: Remove BPF_OBJ_NAME_LEN restriction when looking up bpf program by name | expand |
On Mon, Aug 01, 2022 at 06:24:09AM -0700, Manu Bretelle wrote: > bpftool was limiting the length of names to BPF_OBJ_NAME_LEN in prog_parse > fds. > > Since commit b662000aff84 ("bpftool: Adding support for BTF program names") > we can get the full program name from BTF. > > This patch removes the restriction of name length when running `bpftool > prog show name ${name}`. > > Test: > Tested against some internal program names that were longer than > `BPF_OBJ_NAME_LEN`, here a redacted example of what was ran to test. > > # previous behaviour > $ sudo bpftool prog show name some_long_program_name > Error: can't parse name > # with the patch > $ sudo ./bpftool prog show name some_long_program_name > 123456789: tracing name some_long_program_name tag taghexa gpl .... > ... > ... > ... > # too long > sudo ./bpftool prog show name $(python3 -c 'print("A"*128)') > Error: can't parse name > # not too long but no match > $ sudo ./bpftool prog show name $(python3 -c 'print("A"*127)') > > Signed-off-by: Manu Bretelle <chantr4@gmail.com> > > Reviewed-by: Quentin Monnet <quentin@isovalent.com> tested on tetragon programs ;-) Tested-by: Jiri Olsa <jolsa@kernel.org> jirka > > --- > > v1 -> v2: > * Fix commit message to follow patch submission guidelines > * use strncmp instead of strcmp > * reintroduce arg length check against MAX_PROG_FULL_NAME > > v2 -> v3: > * Fix alignment with opening parenthesis > --- > tools/bpf/bpftool/common.c | 15 ++++++++++++--- > 1 file changed, 12 insertions(+), 3 deletions(-) > > diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c > index 067e9ea59e3b..8727765add88 100644 > --- a/tools/bpf/bpftool/common.c > +++ b/tools/bpf/bpftool/common.c > @@ -722,6 +722,7 @@ print_all_levels(__maybe_unused enum libbpf_print_level level, > > static int prog_fd_by_nametag(void *nametag, int **fds, bool tag) > { > + char prog_name[MAX_PROG_FULL_NAME]; > unsigned int id = 0; > int fd, nb_fds = 0; > void *tmp; > @@ -754,12 +755,20 @@ static int prog_fd_by_nametag(void *nametag, int **fds, bool tag) > goto err_close_fd; > } > > - if ((tag && memcmp(nametag, info.tag, BPF_TAG_SIZE)) || > - (!tag && strncmp(nametag, info.name, BPF_OBJ_NAME_LEN))) { > + if (tag && memcmp(nametag, info.tag, BPF_TAG_SIZE)) { > close(fd); > continue; > } > > + if (!tag) { > + get_prog_full_name(&info, fd, prog_name, > + sizeof(prog_name)); > + if (strncmp(nametag, prog_name, sizeof(prog_name))) { > + close(fd); > + continue; > + } > + } > + > if (nb_fds > 0) { > tmp = realloc(*fds, (nb_fds + 1) * sizeof(int)); > if (!tmp) { > @@ -820,7 +829,7 @@ int prog_parse_fds(int *argc, char ***argv, int **fds) > NEXT_ARGP(); > > name = **argv; > - if (strlen(name) > BPF_OBJ_NAME_LEN - 1) { > + if (strlen(name) > MAX_PROG_FULL_NAME - 1) { > p_err("can't parse name"); > return -1; > } > -- > 2.30.2 >
Hello: This patch was applied to bpf/bpf-next.git (master) by Andrii Nakryiko <andrii@kernel.org>: On Mon, 1 Aug 2022 06:24:09 -0700 you wrote: > bpftool was limiting the length of names to BPF_OBJ_NAME_LEN in prog_parse > fds. > > Since commit b662000aff84 ("bpftool: Adding support for BTF program names") > we can get the full program name from BTF. > > This patch removes the restriction of name length when running `bpftool > prog show name ${name}`. > > [...] Here is the summary with links: - [bpf-next,v3] bpftool: Remove BPF_OBJ_NAME_LEN restriction when looking up bpf program by name https://git.kernel.org/bpf/bpf-next/c/d55dfe587bc0 You are awesome, thank you!
diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c index 067e9ea59e3b..8727765add88 100644 --- a/tools/bpf/bpftool/common.c +++ b/tools/bpf/bpftool/common.c @@ -722,6 +722,7 @@ print_all_levels(__maybe_unused enum libbpf_print_level level, static int prog_fd_by_nametag(void *nametag, int **fds, bool tag) { + char prog_name[MAX_PROG_FULL_NAME]; unsigned int id = 0; int fd, nb_fds = 0; void *tmp; @@ -754,12 +755,20 @@ static int prog_fd_by_nametag(void *nametag, int **fds, bool tag) goto err_close_fd; } - if ((tag && memcmp(nametag, info.tag, BPF_TAG_SIZE)) || - (!tag && strncmp(nametag, info.name, BPF_OBJ_NAME_LEN))) { + if (tag && memcmp(nametag, info.tag, BPF_TAG_SIZE)) { close(fd); continue; } + if (!tag) { + get_prog_full_name(&info, fd, prog_name, + sizeof(prog_name)); + if (strncmp(nametag, prog_name, sizeof(prog_name))) { + close(fd); + continue; + } + } + if (nb_fds > 0) { tmp = realloc(*fds, (nb_fds + 1) * sizeof(int)); if (!tmp) { @@ -820,7 +829,7 @@ int prog_parse_fds(int *argc, char ***argv, int **fds) NEXT_ARGP(); name = **argv; - if (strlen(name) > BPF_OBJ_NAME_LEN - 1) { + if (strlen(name) > MAX_PROG_FULL_NAME - 1) { p_err("can't parse name"); return -1; }
bpftool was limiting the length of names to BPF_OBJ_NAME_LEN in prog_parse fds. Since commit b662000aff84 ("bpftool: Adding support for BTF program names") we can get the full program name from BTF. This patch removes the restriction of name length when running `bpftool prog show name ${name}`. Test: Tested against some internal program names that were longer than `BPF_OBJ_NAME_LEN`, here a redacted example of what was ran to test. # previous behaviour $ sudo bpftool prog show name some_long_program_name Error: can't parse name # with the patch $ sudo ./bpftool prog show name some_long_program_name 123456789: tracing name some_long_program_name tag taghexa gpl .... ... ... ... # too long sudo ./bpftool prog show name $(python3 -c 'print("A"*128)') Error: can't parse name # not too long but no match $ sudo ./bpftool prog show name $(python3 -c 'print("A"*127)') Signed-off-by: Manu Bretelle <chantr4@gmail.com> Reviewed-by: Quentin Monnet <quentin@isovalent.com> --- v1 -> v2: * Fix commit message to follow patch submission guidelines * use strncmp instead of strcmp * reintroduce arg length check against MAX_PROG_FULL_NAME v2 -> v3: * Fix alignment with opening parenthesis --- tools/bpf/bpftool/common.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-)