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/*
* Copyright (C) 2007,2008 Red Hat Inc. All rights reserved.
*
* Module Author: Heinz Mauelshagen <heinzm@redhat.com>
*
* General device-mapper message interface argument parser.
*
* This file is released under the GPL.
*
* device-mapper message parser.
*
*/
#include "dm.h"
#include "dm-message.h"
#include <linux/kernel.h>
#define DM_MSG_PREFIX "dm_message"
/* Basename of a path. */
static inline char *
basename(char *s)
{
char *p = strrchr(s, '/');
return p ? p + 1 : s;
}
/* Get an argument depending on type. */
static void
message_arguments(struct dm_msg *msg, int argc, char **argv)
{
if (argc) {
int i;
struct dm_message_argument *args = msg->spec->args;
for (i = 0; i < args->num_args; i++) {
int r;
unsigned long **ptr = args->ptr;
enum dm_message_argument_type type = args->types[i];
switch (type) {
case dm_msg_base_t:
((char **) ptr)[i] = basename(argv[i]);
break;
case dm_msg_str_t:
((char **) ptr)[i] = argv[i];
break;
case dm_msg_int_t:
r = sscanf(argv[i], "%d", ((int **) ptr)[i]);
goto check;
case dm_msg_uint_t:
r = sscanf(argv[i], "%u",
((unsigned **) ptr)[i]);
goto check;
case dm_msg_uint64_t:
r = sscanf(argv[i], "%llu",
((unsigned long long **) ptr)[i]);
check:
if (r != 1) {
set_bit(dm_msg_ret_undef, &msg->ret);
set_bit(dm_msg_ret_arg, &msg->ret);
}
}
}
}
}
/* Parse message options. */
static void
message_options_parse(struct dm_msg *msg, int argc, char **argv)
{
int hit = 0;
unsigned long *action;
size_t l1 = strlen(*argv), l_hit = 0;
struct dm_message_option *o = msg->spec->options;
char **option, **option_end = o->options + o->num_options;
for (option = o->options, action = o->actions;
option < option_end; option++, action++) {
size_t l2 = strlen(*option);
if (!strnicmp(*argv, *option, min(l1, l2))) {
hit++;
l_hit = l2;
set_bit(*action, &msg->action);
}
}
/* Assume error. */
msg->ret = 0;
set_bit(dm_msg_ret_option, &msg->ret);
if (!hit || l1 > l_hit)
set_bit(dm_msg_ret_undef, &msg->ret); /* Undefined option. */
else if (hit > 1)
set_bit(dm_msg_ret_ambiguous, &msg->ret); /* Ambiguous option.*/
else {
clear_bit(dm_msg_ret_option, &msg->ret); /* Option OK. */
message_arguments(msg, --argc, ++argv);
}
}
static inline void
print_ret(const char *caller, unsigned long ret)
{
struct {
unsigned long err;
const char *err_str;
} static err_msg[] = {
{ dm_msg_ret_ambiguous, "message ambiguous" },
{ dm_msg_ret_inval, "message invalid" },
{ dm_msg_ret_undef, "message undefined" },
{ dm_msg_ret_arg, "message argument" },
{ dm_msg_ret_argcount, "message argument count" },
{ dm_msg_ret_option, "option" },
}, *e = ARRAY_END(err_msg);
while (e-- > err_msg) {
if (test_bit(e->err, &ret))
DMERR("%s %s", caller, e->err_str);
}
}
/* Parse a message action. */
int
dm_message_parse(const char *caller, struct dm_msg *msg, void *context,
int argc, char **argv)
{
int hit = 0;
size_t l1, l_hit = 0;
struct dm_msg_spec *s, *s_hit = NULL,
*s_end = msg->specs + msg->num_specs;
if (argc < 2)
return -EINVAL;
l1 = strlen(*argv);
for (s = msg->specs; s < s_end; s++) {
size_t l2 = strlen(s->cmd);
if (!strnicmp(*argv, s->cmd, min(l1, l2))) {
hit++;
l_hit = l2;
s_hit = s;
}
}
msg->ret = 0;
if (!hit || l1 > l_hit) /* No hit or message string too long. */
set_bit(dm_msg_ret_undef, &msg->ret);
else if (hit > 1) /* Ambiguous message. */
set_bit(dm_msg_ret_ambiguous, &msg->ret);
else if (argc - 2 != s_hit->args->num_args) {
set_bit(dm_msg_ret_undef, &msg->ret);
set_bit(dm_msg_ret_argcount, &msg->ret);
}
if (msg->ret)
goto bad;
msg->action = 0;
msg->spec = s_hit;
set_bit(s_hit->action, &msg->action);
message_options_parse(msg, --argc, ++argv);
if (!msg->ret)
return msg->spec->f(msg, context);
bad:
print_ret(caller, msg->ret);
return -EINVAL;
}
EXPORT_SYMBOL(dm_message_parse);
MODULE_DESCRIPTION(DM_NAME " device-mapper target message parser");
MODULE_AUTHOR("Heinz Mauelshagen <hjm@redhat.com>");
MODULE_LICENSE("GPL");
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