minix/lib/libc/ip/bind.c

354 lines
7.3 KiB
C

#include <unistd.h>
#include <stdint.h>
#include <stdlib.h>
#include <limits.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <netinet/in.h>
#include <net/gen/in.h>
#include <net/gen/tcp.h>
#include <net/gen/tcp_io.h>
#include <net/gen/udp.h>
#include <net/gen/udp_io.h>
#include <sys/un.h>
#include <minix/config.h>
#include <minix/const.h>
#define DEBUG 0
static int _tcp_bind(int socket, const struct sockaddr *address,
socklen_t address_len, nwio_tcpconf_t *tcpconfp);
static int _udp_bind(int socket, const struct sockaddr *address,
socklen_t address_len, nwio_udpopt_t *udpoptp);
static int _uds_bind(int socket, const struct sockaddr *address,
socklen_t address_len, struct sockaddr_un *uds_addr);
int bind(int socket, const struct sockaddr *address, socklen_t address_len)
{
int r;
nwio_tcpconf_t tcpconf;
nwio_udpopt_t udpopt;
struct sockaddr_un uds_addr;
r= ioctl(socket, NWIOGTCPCONF, &tcpconf);
if (r != -1 || (errno != ENOTTY && errno != EBADIOCTL))
{
if (r == -1)
return r;
r= _tcp_bind(socket, address, address_len, &tcpconf);
#if DEBUG
if (r == -1)
{
int t_errno= errno;
fprintf(stderr, "bind(tcp) failed: %s\n",
strerror(errno));
errno= t_errno;
}
#endif
return r;
}
r= ioctl(socket, NWIOGUDPOPT, &udpopt);
if (r != -1 || (errno != ENOTTY && errno != EBADIOCTL))
{
if (r == -1)
return r;
return _udp_bind(socket, address, address_len, &udpopt);
}
r= ioctl(socket, NWIOGUDSADDR, &uds_addr);
if (r != -1 || (errno != ENOTTY && errno != EBADIOCTL))
{
if (r == -1)
return r;
return _uds_bind(socket, address, address_len, &uds_addr);
}
#if DEBUG
fprintf(stderr, "bind: not implemented for fd %d\n", socket);
#endif
errno= ENOSYS;
return -1;
}
static int _tcp_bind(int socket, const struct sockaddr *address,
socklen_t address_len, nwio_tcpconf_t *tcpconfp)
{
int r;
nwio_tcpconf_t tcpconf;
struct sockaddr_in *sinp;
sinp= (struct sockaddr_in *)address;
if (sinp->sin_family != AF_INET || address_len != sizeof(*sinp))
{
#if DEBUG
fprintf(stderr, "bind(tcp): sin_family = %d, len = %d\n",
sinp->sin_family, address_len);
#endif
errno= EAFNOSUPPORT;
return -1;
}
if (sinp->sin_addr.s_addr != INADDR_ANY &&
sinp->sin_addr.s_addr != tcpconfp->nwtc_locaddr)
{
errno= EADDRNOTAVAIL;
return -1;
}
tcpconf.nwtc_flags= 0;
if (sinp->sin_port == 0)
tcpconf.nwtc_flags |= NWTC_LP_SEL;
else
{
tcpconf.nwtc_flags |= NWTC_LP_SET;
tcpconf.nwtc_locport= sinp->sin_port;
}
r= ioctl(socket, NWIOSTCPCONF, &tcpconf);
return r;
}
static int _udp_bind(int socket, const struct sockaddr *address,
socklen_t address_len, nwio_udpopt_t *udpoptp)
{
int r;
unsigned long curr_flags;
nwio_udpopt_t udpopt;
struct sockaddr_in *sinp;
sinp= (struct sockaddr_in *)address;
if (sinp->sin_family != AF_INET || address_len != sizeof(*sinp))
{
#if DEBUG
fprintf(stderr, "bind(udp): sin_family = %d, len = %d\n",
sinp->sin_family, address_len);
#endif
errno= EAFNOSUPPORT;
return -1;
}
if (sinp->sin_addr.s_addr != INADDR_ANY &&
sinp->sin_addr.s_addr != udpoptp->nwuo_locaddr)
{
errno= EADDRNOTAVAIL;
return -1;
}
udpopt.nwuo_flags= 0;
if (sinp->sin_port == 0)
udpopt.nwuo_flags |= NWUO_LP_SEL;
else
{
udpopt.nwuo_flags |= NWUO_LP_SET;
udpopt.nwuo_locport= sinp->sin_port;
}
curr_flags= udpoptp->nwuo_flags;
if (!(curr_flags & NWUO_ACC_MASK))
udpopt.nwuo_flags |= NWUO_EXCL;
if (!(curr_flags & (NWUO_EN_LOC|NWUO_DI_LOC)))
udpopt.nwuo_flags |= NWUO_EN_LOC;
if (!(curr_flags & (NWUO_EN_BROAD|NWUO_DI_BROAD)))
udpopt.nwuo_flags |= NWUO_EN_BROAD;
if (!(curr_flags & (NWUO_RP_SET|NWUO_RP_ANY)))
udpopt.nwuo_flags |= NWUO_RP_ANY;
if (!(curr_flags & (NWUO_RA_SET|NWUO_RA_ANY)))
udpopt.nwuo_flags |= NWUO_RA_ANY;
if (!(curr_flags & (NWUO_RWDATONLY|NWUO_RWDATALL)))
udpopt.nwuo_flags |= NWUO_RWDATALL;
if (!(curr_flags & (NWUO_EN_IPOPT|NWUO_DI_IPOPT)))
udpopt.nwuo_flags |= NWUO_DI_IPOPT;
r= ioctl(socket, NWIOSUDPOPT, &udpopt);
return r;
}
static int in_group(uid_t uid, gid_t gid)
{
int r, i;
int size;
gid_t *list;
size = sysconf(_SC_NGROUPS_MAX);
list = malloc(size * sizeof(gid_t));
if (list == NULL) {
return 0;
}
r= getgroups(size, list);
if (r == -1) {
free(list);
return 0;
}
for (i = 0; i < r; i++) {
if (gid == list[i]) {
free(list);
return 1;
}
}
free(list);
return 0;
}
static int _uds_bind(int socket, const struct sockaddr *address,
socklen_t address_len, struct sockaddr_un *uds_addr)
{
mode_t bits, perm_bits, access_desired;
struct stat buf;
uid_t euid;
gid_t egid;
char real_sun_path[PATH_MAX+1];
char *realpath_result;
int i, r, shift;
int null_found;
int did_mknod;
if (address == NULL) {
errno = EFAULT;
return -1;
}
/* sun_family is always supposed to be AF_UNIX */
if (((struct sockaddr_un *) address)->sun_family != AF_UNIX) {
errno = EAFNOSUPPORT;
return -1;
}
/* an empty path is not supported */
if (((struct sockaddr_un *) address)->sun_path[0] == '\0') {
errno = ENOENT;
return -1;
}
/* the path must be a null terminated string for realpath to work */
for (null_found = i = 0;
i < sizeof(((struct sockaddr_un *) address)->sun_path); i++) {
if (((struct sockaddr_un *) address)->sun_path[i] == '\0') {
null_found = 1;
break;
}
}
if (!null_found) {
errno = EINVAL;
return -1;
}
/*
* Get the realpath(3) of the socket file.
*/
realpath_result = realpath(((struct sockaddr_un *) address)->sun_path,
real_sun_path);
if (realpath_result == NULL) {
return -1;
}
if (strlen(real_sun_path) >= UNIX_PATH_MAX) {
errno = ENAMETOOLONG;
return -1;
}
strcpy(((struct sockaddr_un *) address)->sun_path, real_sun_path);
/*
* input parameters look good -- create the socket file on the
* file system
*/
did_mknod = 0;
r = mknod(((struct sockaddr_un *) address)->sun_path,
S_IFSOCK|S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH, 0);
if (r == -1) {
if (errno == EEXIST) {
/* file already exists, verify that it is a socket */
r = stat(((struct sockaddr_un *) address)->sun_path,
&buf);
if (r == -1) {
return -1;
}
if (!S_ISSOCK(buf.st_mode)) {
errno = EADDRINUSE;
return -1;
}
/* check permissions the permissions of the
* socket file.
*/
/* read + write access */
access_desired = R_BIT | W_BIT;
euid = geteuid();
egid = getegid();
if (euid == -1 || egid == -1) {
errno = EACCES;
return -1;
}
bits = buf.st_mode;
if (euid == ((uid_t) 0)) {
perm_bits = R_BIT | W_BIT;
} else {
if (euid == buf.st_uid) {
shift = 6; /* owner */
} else if (egid == buf.st_gid) {
shift = 3; /* group */
} else if (in_group(euid, buf.st_gid)) {
shift = 3; /* suppl. groups */
} else {
shift = 0; /* other */
}
perm_bits =
(bits >> shift) & (R_BIT | W_BIT | X_BIT);
}
if ((perm_bits | access_desired) != perm_bits) {
errno = EACCES;
return -1;
}
/* if we get here permissions are OK */
} else {
return -1;
}
} else {
did_mknod = 1;
}
/* perform the bind */
r= ioctl(socket, NWIOSUDSADDR, (void *) address);
if (r == -1 && did_mknod) {
/* bind() failed in pfs, so we roll back the
* file system change
*/
unlink(((struct sockaddr_un *) address)->sun_path);
}
return r;
}