libbpf: add internal pin_name

pin_name is the same as section_name where '/' is replaced
by '_'. bpf_object__pin_programs is converted to use pin_name
to avoid the situation where section_name would require creating another
subdirectory for a pin (as, for example, when calling bpf_object__pin_programs
for programs in sections like "cgroup/connect6").

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 97ce9f214002144519a6531d2880f5e015e5351a..e827542ffa3aff9e7d1582732a2943237713c783 100644 (file)
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -124,6 +124,10 @@ struct bpf_program {
        char *name;
        int prog_ifindex;
        char *section_name;
+       /* section_name with / replaced by _; makes recursive pinning
+        * in bpf_object__pin_programs easier
+        */
+       char *pin_name;
        struct bpf_insn *insns;
        size_t insns_cnt, main_prog_cnt;
        enum bpf_prog_type type;
@@ -253,6 +257,7 @@ static void bpf_program__exit(struct bpf_program *prog)
        bpf_program__unload(prog);
        zfree(&prog->name);
        zfree(&prog->section_name);
+       zfree(&prog->pin_name);
        zfree(&prog->insns);
        zfree(&prog->reloc_desc);
 
@@ -261,6 +266,17 @@ static void bpf_program__exit(struct bpf_program *prog)
        prog->idx = -1;
 }
 
+static char *__bpf_program__pin_name(struct bpf_program *prog)
+{
+       char *name, *p;
+
+       name = p = strdup(prog->section_name);
+       while ((p = strchr(p, '/')))
+               *p = '_';
+
+       return name;
+}
+
 static int
 bpf_program__init(void *data, size_t size, char *section_name, int idx,
                  struct bpf_program *prog)
@@ -279,6 +295,13 @@ bpf_program__init(void *data, size_t size, char *section_name, int idx,
                goto errout;
        }
 
+       prog->pin_name = __bpf_program__pin_name(prog);
+       if (!prog->pin_name) {
+               pr_warning("failed to alloc pin name for prog under section(%d) %s\n",
+                          idx, section_name);
+               goto errout;
+       }
+
        prog->insns = malloc(size);
        if (!prog->insns) {
                pr_warning("failed to alloc insns for prog under section %s\n",
@@ -2006,7 +2029,7 @@ int bpf_object__pin_programs(struct bpf_object *obj, const char *path)
                int len;
 
                len = snprintf(buf, PATH_MAX, "%s/%s", path,
-                              prog->section_name);
+                              prog->pin_name);
                if (len < 0) {
                        err = -EINVAL;
                        goto err_unpin_programs;
@@ -2028,7 +2051,7 @@ err_unpin_programs:
                int len;
 
                len = snprintf(buf, PATH_MAX, "%s/%s", path,
-                              prog->section_name);
+                              prog->pin_name);
                if (len < 0)
                        continue;
                else if (len >= PATH_MAX)
@@ -2053,7 +2076,7 @@ int bpf_object__unpin_programs(struct bpf_object *obj, const char *path)
                int len;
 
                len = snprintf(buf, PATH_MAX, "%s/%s", path,
-                              prog->section_name);
+                              prog->pin_name);
                if (len < 0)
                        return -EINVAL;
                else if (len >= PATH_MAX)