%{
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/un.h>
#include <net/if.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <ifaddrs.h>
#include <inttypes.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "lpd.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 kw_cmp(const void *, const void *);
int lookup(char *);
int lgetc(int);
int lungetc(int);
int findeol(void);
int yyerror(const char *, ...)
__attribute__((__format__ (printf, 1, 2)))
__attribute__((__nonnull__ (1)));
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 int errors = 0;
struct lpd_conf *conf = NULL;
enum listen_options {
LO_FAMILY = 0x000001,
LO_PORT = 0x000002,
};
static struct listen_opts {
char *ifx;
int family;
int proto;
in_port_t port;
uint32_t options;
} listen_opts;
static void config_free(struct lpd_conf *);
static void create_listeners(struct listen_opts *);
static void config_listener(struct listener *, struct listen_opts *);
static int local(struct listen_opts *);
static int host_v4(struct listen_opts *);
static int host_v6(struct listen_opts *);
static int host_dns(struct listen_opts *);
static int interface(struct listen_opts *);
static int is_if_in_group(const char *, const char *);
typedef struct {
union {
int64_t number;
char *string;
struct host *host;
} v;
int lineno;
} YYSTYPE;
%}
%token ERROR ARROW INCLUDE
%token LISTEN ON PORT INET4 INET6 LOCAL SOCKET
%token <v.string> STRING
%token <v.number> NUMBER
%type <v.number> family_inet portno
%%
grammar :
| grammar '\n'
| grammar include '\n'
| grammar varset '\n'
| grammar main '\n'
| grammar error '\n' { file->errors++; }
;
include : INCLUDE STRING {
struct file *nfile;
if ((nfile = pushfile($2, 0)) == NULL) {
yyerror("failed to include file %s", $2);
free($2);
YYERROR;
}
free($2);
file = nfile;
lungetc('\n');
}
;
varset : STRING '=' STRING {
char *s = $1;
while (*s++) {
if (isspace((unsigned char)*s)) {
yyerror("macro name cannot contain "
"whitespace");
free($1);
free($3);
YYERROR;
}
}
if (symset($1, $3, 0) == -1)
fatal("cannot store variable");
free($1);
free($3);
}
;
portno : STRING {
struct servent *servent;
servent = getservbyname($1, "tcp");
if (servent == NULL) {
yyerror("invalid port: %s", $1);
free($1);
YYERROR;
}
free($1);
$$ = ntohs(servent->s_port);
}
| NUMBER {
if ($1 <= 0 || $1 > (int)USHRT_MAX) {
yyerror("invalid port: %" PRId64, $1);
YYERROR;
}
$$ = $1;
}
;
family_inet : INET4 { $$ = AF_INET; }
| INET6 { $$ = AF_INET6; }
;
opt_listen : family_inet {
if (listen_opts.options & LO_FAMILY) {
yyerror("address family already specified");
YYERROR;
}
listen_opts.options |= LO_FAMILY;
listen_opts.family = $1;
}
| PORT portno {
if (listen_opts.options & LO_PORT) {
yyerror("port already specified");
YYERROR;
}
listen_opts.options |= LO_PORT;
listen_opts.port = htons($2);
}
;
listener : opt_listen listener
| {
create_listeners(&listen_opts);
}
;
main : LISTEN ON STRING {
memset(&listen_opts, 0, sizeof listen_opts);
listen_opts.ifx = $3;
listen_opts.family = AF_UNSPEC;
listen_opts.proto = PROTO_LPR;
listen_opts.port = htons(PORT_LPR);
} listener
;
%%
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);
log_warnx("%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[] = {
{ "include", INCLUDE },
{ "inet4", INET4 },
{ "inet6", INET6 },
{ "listen", LISTEN },
{ "on", ON },
{ "port", PORT },
{ "socket", SOCKET },
};
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;
pushback_index = 0;
while (1) {
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);
}
}
if (c == '=') {
if ((c = lgetc(0)) != EOF && c == '>')
return (ARROW);
lungetc(c);
c = '=';
}
#define allowed_in_string(x) \
(isalnum(x) || (ispunct(x) && x != '(' && x != ')' && \
x != '{' && x != '}' && x != '<' && x != '>' && \
x != '!' && x != '=' && x != '#' && \
x != ','))
if (isalnum(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)) {
log_warn("warn: cannot stat %s", fname);
return (-1);
}
if (st.st_uid != 0 && st.st_uid != getuid()) {
log_warnx("warn: %s: owner not root or current user", fname);
return (-1);
}
if (st.st_mode & (S_IWGRP | S_IXGRP | S_IRWXO)) {
log_warnx("warn: %s: group/world readable/writeable", fname);
return (-1);
}
return (0);
}
struct file *
pushfile(const char *name, int secret)
{
struct file *nfile;
if ((nfile = calloc(1, sizeof(struct file))) == NULL) {
log_warn("%s", __func__);
return (NULL);
}
if ((nfile->name = strdup(name)) == NULL) {
log_warn("%s", __func__);
free(nfile);
return (NULL);
}
if ((nfile->stream = fopen(nfile->name, "r")) == NULL) {
log_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 lpd_conf *
parse_config(const char *filename, int verbose)
{
struct sym *sym, *next;
conf = calloc(1, sizeof(*conf));
if (conf == NULL)
return NULL;
TAILQ_INIT(&conf->listeners);
errors = 0;
if ((file = pushfile(filename, 0)) == NULL) {
config_free(conf);
return NULL;
}
topfile = file;
setservent(1);
yyparse();
errors = file->errors;
popfile();
endservent();
TAILQ_FOREACH_SAFE(sym, &symhead, entry, next) {
if ((verbose) && !sym->used)
log_warnx("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) {
config_free(conf);
return NULL;
}
return conf;
}
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)
errx(1, "%s: strndup", __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);
}
static void
config_free(struct lpd_conf *c)
{
struct listener *l;
while ((l = TAILQ_FIRST(&c->listeners))) {
TAILQ_REMOVE(&c->listeners, l, entry);
free(l);
}
free(c);
}
static void
create_listeners(struct listen_opts *lo)
{
if (local(lo))
return;
if (interface(lo))
return;
if (host_v4(lo))
return;
if (host_v6(lo))
return;
if (host_dns(lo))
return;
errx(1, "invalid virtual ip or interface: %s", lo->ifx);
}
static void
config_listener(struct listener *l, struct listen_opts *lo)
{
l->sock = -1;
l->proto = lo->proto;
TAILQ_INSERT_TAIL(&conf->listeners, l, entry);
}
static int
local(struct listen_opts *lo)
{
struct sockaddr_un *sun;
struct listener *h;
if (lo->family != AF_UNSPEC && lo->family != AF_LOCAL)
return 0;
if (lo->ifx[0] != '/')
return 0;
h = calloc(1, sizeof(*h));
sun = (struct sockaddr_un *)&h->ss;
sun->sun_len = sizeof(*sun);
sun->sun_family = AF_LOCAL;
if (strlcpy(sun->sun_path, lo->ifx, sizeof(sun->sun_path))
>= sizeof(sun->sun_path))
fatalx("path too long");
config_listener(h, lo);
return (1);
}
static int
host_v4(struct listen_opts *lo)
{
struct in_addr ina;
struct sockaddr_in *sain;
struct listener *h;
if (lo->family != AF_UNSPEC && lo->family != AF_INET)
return (0);
memset(&ina, 0, sizeof(ina));
if (inet_pton(AF_INET, lo->ifx, &ina) != 1)
return (0);
h = calloc(1, sizeof(*h));
sain = (struct sockaddr_in *)&h->ss;
sain->sin_len = sizeof(struct sockaddr_in);
sain->sin_family = AF_INET;
sain->sin_addr.s_addr = ina.s_addr;
sain->sin_port = lo->port;
config_listener(h, lo);
return (1);
}
static int
host_v6(struct listen_opts *lo)
{
struct in6_addr ina6;
struct sockaddr_in6 *sin6;
struct listener *h;
if (lo->family != AF_UNSPEC && lo->family != AF_INET6)
return (0);
memset(&ina6, 0, sizeof(ina6));
if (inet_pton(AF_INET6, lo->ifx, &ina6) != 1)
return (0);
h = calloc(1, sizeof(*h));
sin6 = (struct sockaddr_in6 *)&h->ss;
sin6->sin6_len = sizeof(struct sockaddr_in6);
sin6->sin6_family = AF_INET6;
sin6->sin6_port = lo->port;
memcpy(&sin6->sin6_addr, &ina6, sizeof(ina6));
config_listener(h, lo);
return (1);
}
static int
host_dns(struct listen_opts *lo)
{
struct addrinfo hints, *res0, *res;
int error, cnt = 0;
struct sockaddr_in *sain;
struct sockaddr_in6 *sin6;
struct listener *h;
memset(&hints, 0, sizeof(hints));
hints.ai_family = lo->family;
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = AI_ADDRCONFIG;
error = getaddrinfo(lo->ifx, NULL, &hints, &res0);
if (error == EAI_AGAIN || error == EAI_NODATA || error == EAI_NONAME)
return (0);
if (error) {
log_warnx("warn: host_dns: could not parse \"%s\": %s", lo->ifx,
gai_strerror(error));
return (-1);
}
for (res = res0; res; res = res->ai_next) {
if (res->ai_family != AF_INET &&
res->ai_family != AF_INET6)
continue;
h = calloc(1, sizeof(*h));
h->ss.ss_family = res->ai_family;
if (res->ai_family == AF_INET) {
sain = (struct sockaddr_in *)&h->ss;
sain->sin_len = sizeof(struct sockaddr_in);
sain->sin_addr.s_addr = ((struct sockaddr_in *)
res->ai_addr)->sin_addr.s_addr;
sain->sin_port = lo->port;
} else {
sin6 = (struct sockaddr_in6 *)&h->ss;
sin6->sin6_len = sizeof(struct sockaddr_in6);
memcpy(&sin6->sin6_addr, &((struct sockaddr_in6 *)
res->ai_addr)->sin6_addr, sizeof(struct in6_addr));
sin6->sin6_port = lo->port;
}
config_listener(h, lo);
cnt++;
}
freeaddrinfo(res0);
return (cnt);
}
static int
interface(struct listen_opts *lo)
{
struct ifaddrs *ifap, *p;
struct sockaddr_in *sain;
struct sockaddr_in6 *sin6;
struct listener *h;
int ret = 0;
if (getifaddrs(&ifap) == -1)
fatal("getifaddrs");
for (p = ifap; p != NULL; p = p->ifa_next) {
if (p->ifa_addr == NULL)
continue;
if (strcmp(p->ifa_name, lo->ifx) != 0 &&
!is_if_in_group(p->ifa_name, lo->ifx))
continue;
if (lo->family != AF_UNSPEC && lo->family != p->ifa_addr->sa_family)
continue;
h = calloc(1, sizeof(*h));
switch (p->ifa_addr->sa_family) {
case AF_INET:
sain = (struct sockaddr_in *)&h->ss;
*sain = *(struct sockaddr_in *)p->ifa_addr;
sain->sin_len = sizeof(struct sockaddr_in);
sain->sin_port = lo->port;
break;
case AF_INET6:
sin6 = (struct sockaddr_in6 *)&h->ss;
*sin6 = *(struct sockaddr_in6 *)p->ifa_addr;
sin6->sin6_len = sizeof(struct sockaddr_in6);
sin6->sin6_port = lo->port;
break;
default:
free(h);
continue;
}
config_listener(h, lo);
ret = 1;
}
freeifaddrs(ifap);
return ret;
}
static int
is_if_in_group(const char *ifname, const char *groupname)
{
unsigned int len;
struct ifgroupreq ifgr;
struct ifg_req *ifg;
int s;
int ret = 0;
if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
err(1, "socket");
memset(&ifgr, 0, sizeof(ifgr));
if (strlcpy(ifgr.ifgr_name, ifname, IFNAMSIZ) >= IFNAMSIZ)
errx(1, "interface name too large");
if (ioctl(s, SIOCGIFGROUP, (caddr_t)&ifgr) == -1) {
if (errno == EINVAL || errno == ENOTTY)
goto end;
err(1, "SIOCGIFGROUP");
}
len = ifgr.ifgr_len;
ifgr.ifgr_groups = calloc(len/sizeof(struct ifg_req),
sizeof(struct ifg_req));
if (ioctl(s, SIOCGIFGROUP, (caddr_t)&ifgr) == -1)
err(1, "SIOCGIFGROUP");
ifg = ifgr.ifgr_groups;
for (; ifg && len >= sizeof(struct ifg_req); ifg++) {
len -= sizeof(struct ifg_req);
if (strcmp(ifg->ifgrq_group, groupname) == 0) {
ret = 1;
break;
}
}
free(ifgr.ifgr_groups);
end:
close(s);
return ret;
}
