toys/other/modinfo.c

/* modinfo.c - Display module info
 *
 * Copyright 2012 Andre Renaud <andre@bluewatersys.com>

USE_MODINFO(NEWTOY(modinfo, "<1F:0", TOYFLAG_BIN))

config MODINFO
  bool "modinfo"
  default y
  help
    usage: modinfo [-0] [-F field] [modulename...]
*/

#define FOR_modinfo
#include "toys.h"

GLOBALS(
  char *field;
)

static const char *modinfo_tags[] = {
  "alias", "license", "description", "author", "vermagic",
  "srcversion", "intree", "parm", "depends",
};

static void output_field(const char *field, const char *value)
{
  int len;

  if (TT.field && strcmp(TT.field, field) != 0) return;

  len = strlen(field);

  if (TT.field) xprintf("%s", value);
  else xprintf("%s:%*s%s", field, 15 - len, "", value);
  if (toys.optflags & FLAG_0) xwrite(fileno(stdout), "\0", 1);
  else xputs("");
}


static void modinfo_file(struct dirtree *dir)
{
  int fd, len, i;
  char *buf, *pos;
  char *full_name;

  full_name = dirtree_path(dir, NULL);

  output_field("filename", full_name);
  fd = xopen(full_name, O_RDONLY);
  len = fdlength(fd);
  buf = xmalloc(len);
  xreadall(fd, buf, len);

  for (pos = buf; pos < buf + len + 10; pos++) {
    if (*pos) continue;

    for (i = 0; i < sizeof(modinfo_tags) / sizeof(modinfo_tags[0]); i++) {
      const char *str = modinfo_tags[i];
      int len = strlen(str);
      if (strncmp(pos + 1, str, len) == 0 && pos[len + 1] == '=')
        output_field(str, &pos[len + 2]);
    }
  }

  free(full_name);
  free(buf);
  close(fd);
}

static int check_module(struct dirtree *new)
{
  if (S_ISREG(new->st.st_mode)) {
    char **s;
    for (s = toys.optargs; *s; s++) {
      int len = strlen(*s);
      if (!strncmp(*s, new->name, len) && !strcmp(new->name+len, ".ko"))
        modinfo_file(new);
    }
  }

  return dirtree_notdotdot(new);
}

void modinfo_main(void)
{
  struct utsname uts;

  if (uname(&uts) < 0) perror_exit("bad uname");
  sprintf(toybuf, "/lib/modules/%s", uts.release);
  dirtree_read(toybuf, check_module);
}