Messages in this thread Patch in this message | | | Date | Tue, 7 Jul 2015 16:37:02 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [RFC PATCH v10 20/50] bpf tools: Introduce accessors for struct bpf_program |
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Em Wed, Jul 01, 2015 at 02:14:08AM +0000, Wang Nan escreveu: > This patch introduces accessors for user of libbpf to retrieve section > name and fd of a opened/loaded eBPF program. 'struct bpf_prog_handler' > is used for that purpose. Accessors of programs section name and file > descriptor are provided. Set/get private data are also impelmented. > > Signed-off-by: Wang Nan <wangnan0@huawei.com> > Acked-by: Alexei Starovoitov <ast@plumgrid.com> > --- > tools/lib/bpf/libbpf.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++ > tools/lib/bpf/libbpf.h | 25 +++++++++++++++ > 2 files changed, 107 insertions(+) > > diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c > index 33452f8..e4c5f07 100644 > --- a/tools/lib/bpf/libbpf.c > +++ b/tools/lib/bpf/libbpf.c > @@ -98,6 +98,10 @@ struct bpf_program { > int nr_reloc; > > int fd; > + > + struct bpf_object *obj; > + void *priv; > + bpf_program_clear_priv_t clear_priv; > }; > > struct bpf_object { > @@ -150,6 +154,12 @@ static void bpf_program__clear(struct bpf_program *prog) > if (!prog) > return; > > + if (prog->clear_priv) > + prog->clear_priv(prog, prog->priv); > + > + prog->priv = NULL; > + prog->clear_priv = NULL; > + > bpf_program__unload(prog); > zfree(&prog->section_name); > zfree(&prog->insns); > @@ -211,6 +221,7 @@ bpf_program__new(struct bpf_object *obj, void *data, size_t size, > prog->insns_cnt * sizeof(struct bpf_insn)); > prog->idx = idx; > prog->fd = -1; > + prog->obj = obj; > > return prog; > out: > @@ -924,3 +935,74 @@ void bpf_object__close(struct bpf_object *obj) > > free(obj); > } > + > +struct bpf_program * > +bpf_program__next(struct bpf_program *prev, struct bpf_object *obj) > +{ > + size_t idx; > + > + if (!obj->programs) > + return NULL; > + /* First handler */ > + if (prev == NULL) > + return &obj->programs[0]; > + > + if (prev->obj != obj) { > + pr_warning("error: program handler doesn't match object\n"); > + return NULL; > + } > + > + idx = (prev - obj->programs) + 1; > + if (idx >= obj->nr_programs) > + return NULL; > + return &obj->programs[idx]; > +} > + > +int bpf_program__set_private(struct bpf_program *prog, > + void *priv, > + bpf_program_clear_priv_t clear_priv) > +{ > + if (prog->priv && prog->clear_priv) > + prog->clear_priv(prog, prog->priv); > + > + prog->priv = priv; > + prog->clear_priv = clear_priv; > + return 0; > +} > + > +int bpf_program__get_private(struct bpf_program *prog, void **ppriv) > +{ > + *ppriv = prog->priv; > + return 0; > +} > + > +int bpf_program__get_title(struct bpf_program *prog, > + const char **ptitle, bool dup) > +{ > + const char *title; > + > + if (!ptitle) > + return -EINVAL; > + > + title = prog->section_name; > + if (dup) { > + title = strdup(title); > + if (!title) { > + pr_warning("failed to strdup program title\n"); > + *ptitle = NULL; > + return -ENOMEM; > + } > + } > + > + *ptitle = title; > + return 0; > +} > + > +int bpf_program__get_fd(struct bpf_program *prog, int *pfd) > +{ > + if (!pfd) > + return -EINVAL; > + > + *pfd = prog->fd; > + return 0;
Why not:
int bpf_program__fd(struct bpf_program *prog) { return prog->fd; }
Or plain ditch completely this function and go ahead and use: prog->fd;
I see, you don't export the bpf_program struct definition, but then why not return it straight away?
Ditto for bpf_program__get_title()
- Arnaldo
> +} > diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h > index 3e69600..9e0e102 100644 > --- a/tools/lib/bpf/libbpf.h > +++ b/tools/lib/bpf/libbpf.h > @@ -9,6 +9,7 @@ > #define __BPF_LIBBPF_H > > #include <stdio.h> > +#include <stdbool.h> > > /* > * In include/linux/compiler-gcc.h, __printf is defined. However > @@ -34,6 +35,30 @@ void bpf_object__close(struct bpf_object *object); > int bpf_object__load(struct bpf_object *obj); > int bpf_object__unload(struct bpf_object *obj); > > +/* Accessors of bpf_program. */ > +struct bpf_program; > +struct bpf_program *bpf_program__next(struct bpf_program *prog, > + struct bpf_object *obj); > + > +#define bpf_object__for_each_program(pos, obj) \ > + for ((pos) = bpf_program__next(NULL, (obj)); \ > + (pos) != NULL; \ > + (pos) = bpf_program__next((pos), (obj))) > + > +typedef void (*bpf_program_clear_priv_t)(struct bpf_program *, > + void *); > + > +int bpf_program__set_private(struct bpf_program *prog, void *priv, > + bpf_program_clear_priv_t clear_priv); > + > +int bpf_program__get_private(struct bpf_program *prog, > + void **ppriv); > + > +int bpf_program__get_title(struct bpf_program *prog, > + const char **ptitle, bool dup); > + > +int bpf_program__get_fd(struct bpf_program *prog, int *pfd); > + > /* > * We don't need __attribute__((packed)) now since it is > * unnecessary for 'bpf_map_def' because they are all aligned. > -- > 1.8.3.4
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