%{
#include <sys/types.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <net/if.h>
#include <ctype.h>
#include <unistd.h>
#include <err.h>
#include <errno.h>
#include <limits.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include <syslog.h>
#include <event.h>
#include "ifstated.h"
#include "log.h"
TAILQ_HEAD(files, file) files = TAILQ_HEAD_INITIALIZER(files);
static struct file {
TAILQ_ENTRY(file) entry;
FILE *stream;
char *name;
int lineno;
int errors;
} *file, *topfile;
struct file *pushfile(const char *, int);
int popfile(void);
int check_file_secrecy(int, const char *);
int yyparse(void);
int yylex(void);
int yyerror(const char *, ...)
__attribute__((__format__ (printf, 1, 2)))
__attribute__((__nonnull__ (1)));
int kw_cmp(const void *, const void *);
int lookup(char *);
int lgetc(int);
int lungetc(int);
int findeol(void);
TAILQ_HEAD(symhead, sym) symhead = TAILQ_HEAD_INITIALIZER(symhead);
struct sym {
TAILQ_ENTRY(sym) entry;
int used;
int persist;
char *nam;
char *val;
};
int symset(const char *, const char *, int);
char *symget(const char *);
static struct ifsd_config *conf;
char *start_state;
struct ifsd_action *curaction;
struct ifsd_state *curstate;
void link_states(struct ifsd_action *);
void set_expression_depth(struct ifsd_expression *, int);
void init_state(struct ifsd_state *);
struct ifsd_ifstate *new_ifstate(char *, int);
struct ifsd_external *new_external(char *, u_int32_t);
typedef struct {
union {
int64_t number;
char *string;
struct in_addr addr;
struct ifsd_expression *expression;
struct ifsd_ifstate *ifstate;
struct ifsd_external *external;
} v;
int lineno;
} YYSTYPE;
%}
%token STATE INITSTATE
%token LINK UP DOWN UNKNOWN
%token IF RUN SETSTATE EVERY INIT
%left AND OR
%left UNARY
%token ERROR
%token <v.string> STRING
%token <v.number> NUMBER
%type <v.string> string
%type <v.string> interface
%type <v.ifstate> if_test
%type <v.external> ext_test
%type <v.expression> expr term
%%
grammar :
| grammar '\n'
| grammar conf_main '\n'
| grammar varset '\n'
| grammar action '\n'
| grammar state '\n'
| grammar error '\n' { file->errors++; }
;
string : string STRING {
if (asprintf(&$$, "%s %s", $1, $2) == -1) {
free($1);
free($2);
yyerror("string: asprintf");
YYERROR;
}
free($1);
free($2);
}
| STRING
;
varset : STRING '=' string {
char *s = $1;
if (conf->opts & IFSD_OPT_VERBOSE)
printf("%s = \"%s\"\n", $1, $3);
while (*s++) {
if (isspace((unsigned char)*s)) {
yyerror("macro name cannot contain "
"whitespace");
free($1);
free($3);
YYERROR;
}
}
if (symset($1, $3, 0) == -1) {
free($1);
free($3);
yyerror("cannot store variable");
YYERROR;
}
free($1);
free($3);
}
;
conf_main : INITSTATE STRING {
start_state = $2;
}
;
interface : STRING {
if (if_nametoindex($1) == 0) {
yyerror("unknown interface %s", $1);
free($1);
YYERROR;
}
$$ = $1;
}
;
optnl : '\n' optnl
|
;
nl : '\n' optnl
;
action : RUN STRING {
struct ifsd_action *action;
if ((action = calloc(1, sizeof(*action))) == NULL)
err(1, "action: calloc");
action->type = IFSD_ACTION_COMMAND;
action->act.command = $2;
TAILQ_INSERT_TAIL(&curaction->act.c.actions,
action, entries);
}
| SETSTATE STRING {
struct ifsd_action *action;
if (curstate == NULL) {
free($2);
yyerror("set-state must be used inside 'if'");
YYERROR;
}
if ((action = calloc(1, sizeof(*action))) == NULL)
err(1, "action: calloc");
action->type = IFSD_ACTION_CHANGESTATE;
action->act.statename = $2;
TAILQ_INSERT_TAIL(&curaction->act.c.actions,
action, entries);
}
| IF {
struct ifsd_action *action;
if ((action = calloc(1, sizeof(*action))) == NULL)
err(1, "action: calloc");
action->type = IFSD_ACTION_CONDITION;
TAILQ_INIT(&action->act.c.actions);
TAILQ_INSERT_TAIL(&curaction->act.c.actions,
action, entries);
action->parent = curaction;
curaction = action;
} expr action_block {
set_expression_depth(curaction->act.c.expression, 0);
curaction = curaction->parent;
}
;
action_block : optnl '{' optnl action_l '}'
| optnl action
;
action_l : action_l action nl
| action nl
;
init : INIT {
if (curstate != NULL)
curaction = curstate->init;
else
curaction = conf->initstate.init;
} action_block {
if (curstate != NULL)
curaction = curstate->body;
else
curaction = conf->initstate.body;
}
;
if_test : interface '.' LINK '.' UP {
$$ = new_ifstate($1, IFSD_LINKUP);
}
| interface '.' LINK '.' DOWN {
$$ = new_ifstate($1, IFSD_LINKDOWN);
}
| interface '.' LINK '.' UNKNOWN {
$$ = new_ifstate($1, IFSD_LINKUNKNOWN);
}
;
ext_test : STRING EVERY NUMBER {
if ($3 <= 0 || $3 > UINT_MAX) {
yyerror("invalid interval: %lld", $3);
free($1);
YYERROR;
}
$$ = new_external($1, $3);
free($1);
}
;
term : if_test {
if (($$ = calloc(1, sizeof(*$$))) == NULL)
err(1, NULL);
curaction->act.c.expression = $$;
$$->type = IFSD_OPER_IFSTATE;
$$->u.ifstate = $1;
TAILQ_INSERT_TAIL(&$1->expressions, $$, entries);
}
| ext_test {
if (($$ = calloc(1, sizeof(*$$))) == NULL)
err(1, NULL);
curaction->act.c.expression = $$;
$$->type = IFSD_OPER_EXTERNAL;
$$->u.external = $1;
TAILQ_INSERT_TAIL(&$1->expressions, $$, entries);
}
| '(' expr ')' {
$$ = $2;
}
;
expr : '!' expr %prec UNARY {
if (($$ = calloc(1, sizeof(*$$))) == NULL)
err(1, NULL);
curaction->act.c.expression = $$;
$$->type = IFSD_OPER_NOT;
$2->parent = $$;
$$->right = $2;
}
| expr AND expr {
if (($$ = calloc(1, sizeof(*$$))) == NULL)
err(1, NULL);
curaction->act.c.expression = $$;
$$->type = IFSD_OPER_AND;
$1->parent = $$;
$3->parent = $$;
$$->left = $1;
$$->right = $3;
}
| expr OR expr {
if (($$ = calloc(1, sizeof(*$$))) == NULL)
err(1, NULL);
curaction->act.c.expression = $$;
$$->type = IFSD_OPER_OR;
$1->parent = $$;
$3->parent = $$;
$$->left = $1;
$$->right = $3;
}
| term
;
state : STATE string {
struct ifsd_state *state = NULL;
TAILQ_FOREACH(state, &conf->states, entries)
if (!strcmp(state->name, $2)) {
yyerror("state %s already exists", $2);
free($2);
YYERROR;
}
if ((state = calloc(1, sizeof(*curstate))) == NULL)
err(1, NULL);
init_state(state);
state->name = $2;
curstate = state;
curaction = state->body;
} optnl '{' optnl stateopts_l '}' {
TAILQ_INSERT_TAIL(&conf->states, curstate, entries);
curstate = NULL;
curaction = conf->initstate.body;
}
;
stateopts_l : stateopts_l stateoptsl
| stateoptsl
;
stateoptsl : init nl
| action nl
;
%%
struct keywords {
const char *k_name;
int k_val;
};
int
yyerror(const char *fmt, ...)
{
va_list ap;
char *msg;
file->errors++;
va_start(ap, fmt);
if (vasprintf(&msg, fmt, ap) == -1)
fatalx("yyerror vasprintf");
va_end(ap);
logit(LOG_CRIT, "%s:%d: %s", file->name, yylval.lineno, msg);
free(msg);
return (0);
}
int
kw_cmp(const void *k, const void *e)
{
return (strcmp(k, ((const struct keywords *)e)->k_name));
}
int
lookup(char *s)
{
static const struct keywords keywords[] = {
{ "&&", AND},
{ "down", DOWN},
{ "every", EVERY},
{ "if", IF},
{ "init", INIT},
{ "init-state", INITSTATE},
{ "link", LINK},
{ "run", RUN},
{ "set-state", SETSTATE},
{ "state", STATE},
{ "unknown", UNKNOWN},
{ "up", UP},
{ "||", OR}
};
const struct keywords *p;
p = bsearch(s, keywords, sizeof(keywords)/sizeof(keywords[0]),
sizeof(keywords[0]), kw_cmp);
if (p)
return (p->k_val);
else
return (STRING);
}
#define MAXPUSHBACK 128
char *parsebuf;
int parseindex;
char pushback_buffer[MAXPUSHBACK];
int pushback_index = 0;
int
lgetc(int quotec)
{
int c, next;
if (parsebuf) {
if (parseindex >= 0) {
c = (unsigned char)parsebuf[parseindex++];
if (c != '\0')
return (c);
parsebuf = NULL;
} else
parseindex++;
}
if (pushback_index)
return ((unsigned char)pushback_buffer[--pushback_index]);
if (quotec) {
if ((c = getc(file->stream)) == EOF) {
yyerror("reached end of file while parsing "
"quoted string");
if (file == topfile || popfile() == EOF)
return (EOF);
return (quotec);
}
return (c);
}
while ((c = getc(file->stream)) == '\\') {
next = getc(file->stream);
if (next != '\n') {
c = next;
break;
}
yylval.lineno = file->lineno;
file->lineno++;
}
while (c == EOF) {
if (file == topfile || popfile() == EOF)
return (EOF);
c = getc(file->stream);
}
return (c);
}
int
lungetc(int c)
{
if (c == EOF)
return (EOF);
if (parsebuf) {
parseindex--;
if (parseindex >= 0)
return (c);
}
if (pushback_index + 1 >= MAXPUSHBACK)
return (EOF);
pushback_buffer[pushback_index++] = c;
return (c);
}
int
findeol(void)
{
int c;
parsebuf = NULL;
while (1) {
if (pushback_index)
c = (unsigned char)pushback_buffer[--pushback_index];
else
c = lgetc(0);
if (c == '\n') {
file->lineno++;
break;
}
if (c == EOF)
break;
}
return (ERROR);
}
int
yylex(void)
{
char buf[8096];
char *p, *val;
int quotec, next, c;
int token;
top:
p = buf;
while ((c = lgetc(0)) == ' ' || c == '\t')
;
yylval.lineno = file->lineno;
if (c == '#')
while ((c = lgetc(0)) != '\n' && c != EOF)
;
if (c == '$' && parsebuf == NULL) {
while (1) {
if ((c = lgetc(0)) == EOF)
return (0);
if (p + 1 >= buf + sizeof(buf) - 1) {
yyerror("string too long");
return (findeol());
}
if (isalnum(c) || c == '_') {
*p++ = c;
continue;
}
*p = '\0';
lungetc(c);
break;
}
val = symget(buf);
if (val == NULL) {
yyerror("macro '%s' not defined", buf);
return (findeol());
}
parsebuf = val;
parseindex = 0;
goto top;
}
switch (c) {
case '\'':
case '"':
quotec = c;
while (1) {
if ((c = lgetc(quotec)) == EOF)
return (0);
if (c == '\n') {
file->lineno++;
continue;
} else if (c == '\\') {
if ((next = lgetc(quotec)) == EOF)
return (0);
if (next == quotec || next == ' ' ||
next == '\t')
c = next;
else if (next == '\n') {
file->lineno++;
continue;
} else
lungetc(next);
} else if (c == quotec) {
*p = '\0';
break;
} else if (c == '\0') {
yyerror("syntax error");
return (findeol());
}
if (p + 1 >= buf + sizeof(buf) - 1) {
yyerror("string too long");
return (findeol());
}
*p++ = c;
}
yylval.v.string = strdup(buf);
if (yylval.v.string == NULL)
err(1, "%s", __func__);
return (STRING);
}
#define allowed_to_end_number(x) \
(isspace(x) || x == ')' || x ==',' || x == '/' || x == '}' || x == '=')
if (c == '-' || isdigit(c)) {
do {
*p++ = c;
if ((size_t)(p-buf) >= sizeof(buf)) {
yyerror("string too long");
return (findeol());
}
} while ((c = lgetc(0)) != EOF && isdigit(c));
lungetc(c);
if (p == buf + 1 && buf[0] == '-')
goto nodigits;
if (c == EOF || allowed_to_end_number(c)) {
const char *errstr = NULL;
*p = '\0';
yylval.v.number = strtonum(buf, LLONG_MIN,
LLONG_MAX, &errstr);
if (errstr) {
yyerror("\"%s\" invalid number: %s",
buf, errstr);
return (findeol());
}
return (NUMBER);
} else {
nodigits:
while (p > buf + 1)
lungetc((unsigned char)*--p);
c = (unsigned char)*--p;
if (c == '-')
return (c);
}
}
#define allowed_in_string(x) \
(isalnum(x) || (ispunct(x) && x != '(' && x != ')' && \
x != '{' && x != '}' && \
x != '!' && x != '=' && x != '#' && \
x != ',' && x != '.'))
if (isalnum(c) || c == ':' || c == '_' || c == '&' || c == '|') {
do {
*p++ = c;
if ((size_t)(p-buf) >= sizeof(buf)) {
yyerror("string too long");
return (findeol());
}
} while ((c = lgetc(0)) != EOF && (allowed_in_string(c)));
lungetc(c);
*p = '\0';
if ((token = lookup(buf)) == STRING)
if ((yylval.v.string = strdup(buf)) == NULL)
err(1, "%s", __func__);
return (token);
}
if (c == '\n') {
yylval.lineno = file->lineno;
file->lineno++;
}
if (c == EOF)
return (0);
return (c);
}
int
check_file_secrecy(int fd, const char *fname)
{
struct stat st;
if (fstat(fd, &st)) {
warn("cannot stat %s", fname);
return (-1);
}
if (st.st_uid != 0 && st.st_uid != getuid()) {
warnx("%s: owner not root or current user", fname);
return (-1);
}
if (st.st_mode & (S_IWGRP | S_IXGRP | S_IRWXO)) {
warnx("%s: group writable or world read/writable", fname);
return (-1);
}
return (0);
}
struct file *
pushfile(const char *name, int secret)
{
struct file *nfile;
if ((nfile = calloc(1, sizeof(struct file))) == NULL) {
warn("%s", __func__);
return (NULL);
}
if ((nfile->name = strdup(name)) == NULL) {
warn("%s", __func__);
free(nfile);
return (NULL);
}
if ((nfile->stream = fopen(nfile->name, "r")) == NULL) {
warn("%s: %s", __func__, nfile->name);
free(nfile->name);
free(nfile);
return (NULL);
} else if (secret &&
check_file_secrecy(fileno(nfile->stream), nfile->name)) {
fclose(nfile->stream);
free(nfile->name);
free(nfile);
return (NULL);
}
nfile->lineno = 1;
TAILQ_INSERT_TAIL(&files, nfile, entry);
return (nfile);
}
int
popfile(void)
{
struct file *prev;
if ((prev = TAILQ_PREV(file, files, entry)) != NULL)
prev->errors += file->errors;
TAILQ_REMOVE(&files, file, entry);
fclose(file->stream);
free(file->name);
free(file);
file = prev;
return (file ? 0 : EOF);
}
struct ifsd_config *
parse_config(char *filename, int opts)
{
int errors = 0;
struct sym *sym, *next;
struct ifsd_state *state;
if ((conf = calloc(1, sizeof(struct ifsd_config))) == NULL) {
err(1, "%s", __func__);
return (NULL);
}
if ((file = pushfile(filename, 0)) == NULL) {
free(conf);
return (NULL);
}
topfile = file;
TAILQ_INIT(&conf->states);
init_state(&conf->initstate);
curaction = conf->initstate.body;
conf->opts = opts;
yyparse();
TAILQ_FOREACH(state, &conf->states, entries) {
link_states(state->init);
link_states(state->body);
}
errors = file->errors;
popfile();
if (start_state != NULL) {
TAILQ_FOREACH(state, &conf->states, entries) {
if (strcmp(start_state, state->name) == 0) {
conf->curstate = state;
break;
}
}
if (conf->curstate == NULL)
errx(1, "invalid start state %s", start_state);
} else {
conf->curstate = TAILQ_FIRST(&conf->states);
}
TAILQ_FOREACH_SAFE(sym, &symhead, entry, next) {
if ((conf->opts & IFSD_OPT_VERBOSE2) && !sym->used)
fprintf(stderr, "warning: macro '%s' not "
"used\n", sym->nam);
if (!sym->persist) {
free(sym->nam);
free(sym->val);
TAILQ_REMOVE(&symhead, sym, entry);
free(sym);
}
}
if (errors) {
clear_config(conf);
errors = 0;
return (NULL);
}
return (conf);
}
void
link_states(struct ifsd_action *action)
{
struct ifsd_action *subaction;
switch (action->type) {
default:
case IFSD_ACTION_COMMAND:
break;
case IFSD_ACTION_CHANGESTATE: {
struct ifsd_state *state;
TAILQ_FOREACH(state, &conf->states, entries) {
if (strcmp(action->act.statename,
state->name) == 0) {
action->act.nextstate = state;
break;
}
}
if (state == NULL) {
fprintf(stderr, "error: state '%s' not declared\n",
action->act.statename);
file->errors++;
}
break;
}
case IFSD_ACTION_CONDITION:
TAILQ_FOREACH(subaction, &action->act.c.actions, entries)
link_states(subaction);
break;
}
}
int
symset(const char *nam, const char *val, int persist)
{
struct sym *sym;
TAILQ_FOREACH(sym, &symhead, entry) {
if (strcmp(nam, sym->nam) == 0)
break;
}
if (sym != NULL) {
if (sym->persist == 1)
return (0);
else {
free(sym->nam);
free(sym->val);
TAILQ_REMOVE(&symhead, sym, entry);
free(sym);
}
}
if ((sym = calloc(1, sizeof(*sym))) == NULL)
return (-1);
sym->nam = strdup(nam);
if (sym->nam == NULL) {
free(sym);
return (-1);
}
sym->val = strdup(val);
if (sym->val == NULL) {
free(sym->nam);
free(sym);
return (-1);
}
sym->used = 0;
sym->persist = persist;
TAILQ_INSERT_TAIL(&symhead, sym, entry);
return (0);
}
int
cmdline_symset(char *s)
{
char *sym, *val;
int ret;
if ((val = strrchr(s, '=')) == NULL)
return (-1);
sym = strndup(s, val - s);
if (sym == NULL)
err(1, "%s", __func__);
ret = symset(sym, val + 1, 1);
free(sym);
return (ret);
}
char *
symget(const char *nam)
{
struct sym *sym;
TAILQ_FOREACH(sym, &symhead, entry) {
if (strcmp(nam, sym->nam) == 0) {
sym->used = 1;
return (sym->val);
}
}
return (NULL);
}
void
set_expression_depth(struct ifsd_expression *expression, int depth)
{
expression->depth = depth;
if (conf->maxdepth < depth)
conf->maxdepth = depth;
if (expression->left != NULL)
set_expression_depth(expression->left, depth + 1);
if (expression->right != NULL)
set_expression_depth(expression->right, depth + 1);
}
void
init_state(struct ifsd_state *state)
{
TAILQ_INIT(&state->interface_states);
TAILQ_INIT(&state->external_tests);
if ((state->init = calloc(1, sizeof(*state->init))) == NULL)
err(1, "%s", __func__);
state->init->type = IFSD_ACTION_CONDITION;
TAILQ_INIT(&state->init->act.c.actions);
if ((state->body = calloc(1, sizeof(*state->body))) == NULL)
err(1, "%s", __func__);
state->body->type = IFSD_ACTION_CONDITION;
TAILQ_INIT(&state->body->act.c.actions);
}
struct ifsd_ifstate *
new_ifstate(char *ifname, int s)
{
struct ifsd_ifstate *ifstate = NULL;
struct ifsd_state *state;
if (curstate != NULL)
state = curstate;
else
state = &conf->initstate;
TAILQ_FOREACH(ifstate, &state->interface_states, entries)
if (strcmp(ifstate->ifname, ifname) == 0 &&
ifstate->ifstate == s)
break;
if (ifstate == NULL) {
if ((ifstate = calloc(1, sizeof(*ifstate))) == NULL)
err(1, "%s", __func__);
if (strlcpy(ifstate->ifname, ifname,
sizeof(ifstate->ifname)) >= sizeof(ifstate->ifname))
errx(1, "ifname strlcpy truncation");
free(ifname);
ifstate->ifstate = s;
TAILQ_INIT(&ifstate->expressions);
TAILQ_INSERT_TAIL(&state->interface_states, ifstate, entries);
}
ifstate->prevstate = -1;
ifstate->refcount++;
return (ifstate);
}
struct ifsd_external *
new_external(char *command, u_int32_t frequency)
{
struct ifsd_external *external = NULL;
struct ifsd_state *state;
if (curstate != NULL)
state = curstate;
else
state = &conf->initstate;
TAILQ_FOREACH(external, &state->external_tests, entries)
if (strcmp(external->command, command) == 0 &&
external->frequency == frequency)
break;
if (external == NULL) {
if ((external = calloc(1, sizeof(*external))) == NULL)
err(1, "%s", __func__);
if ((external->command = strdup(command)) == NULL)
err(1, "%s", __func__);
external->frequency = frequency;
TAILQ_INIT(&external->expressions);
TAILQ_INSERT_TAIL(&state->external_tests, external, entries);
}
external->prevstatus = -1;
external->refcount++;
return (external);
}
