minix/minix/net/inet/inet.c
David van Moolenbroek dfc3261535 PFS, inet: use static UID to drop privileges
Previously, services would obtain the user ID of "service" through
getpwnam(3).  While this approach is conceptually better, it also
imposes linking against libc which in turn causes problems with
printf(3), which already led to PFS no longer dropping privileges at
all.  For now, we hardcode SERVICE_UID and use that instead.

In the future, two changes should allow removal of SERVICE_UID again:
- "service edit" should cause RS to request that a service (such as
  PFS) drop privileges through SEF, using the user ID resolved by
  service(8), or something similar;
- a future devfs should make it possible for inet to start without
  root privileges altogether.

Change-Id: Ie02a1e888cde325806fc0ae76909943ac42c9b96
2015-06-06 21:42:48 +00:00

365 lines
7.1 KiB
C

/* this file contains the interface of the network software with rest of
minix. Furthermore it contains the main loop of the network task.
Copyright 1995 Philip Homburg
*/
#include "inet.h"
#include <fcntl.h>
#include <unistd.h>
#include <minix/ds.h>
#include <minix/endpoint.h>
#include <minix/chardriver.h>
#include <minix/rs.h>
#include <sys/types.h>
#include <pwd.h>
#include "mq.h"
#include "qp.h"
#include "proto.h"
#include "generic/type.h"
#include "generic/arp.h"
#include "generic/assert.h"
#include "generic/buf.h"
#include "generic/clock.h"
#include "generic/eth.h"
#include "generic/event.h"
#include "generic/ip.h"
#include "generic/psip.h"
#include "generic/rand256.h"
#include "generic/sr.h"
#include "generic/tcp.h"
#include "generic/udp.h"
THIS_FILE
#define RANDOM_DEV_NAME "/dev/random"
endpoint_t this_proc; /* Process number of this server. */
/* Killing Solaris */
int killer_inet= 0;
#ifdef BUF_CONSISTENCY_CHECK
extern int inet_buf_debug;
#endif
#if HZ_DYNAMIC
u32_t system_hz;
#endif
static void nw_conf(void);
static void nw_init(void);
static void ds_event(void);
/* SEF functions and variables. */
static void sef_local_startup(void);
static int sef_cb_init_fresh(int type, sef_init_info_t *info);
int main(int argc, char *argv[])
{
message mess;
int ipc_status;
int r;
/* SEF local startup. */
sef_local_startup();
while (TRUE)
{
#ifdef BUF_CONSISTENCY_CHECK
if (inet_buf_debug)
{
static int buf_debug_count= 0;
if (++buf_debug_count >= inet_buf_debug)
{
buf_debug_count= 0;
if (!bf_consistency_check())
break;
}
}
#endif
if (ev_head)
{
ev_process();
continue;
}
if (clck_call_expire)
{
clck_expire_timers();
continue;
}
r= sef_receive_status(ANY, &mess, &ipc_status);
if (r<0)
{
ip_panic(("unable to receive: %d", r));
}
reset_time();
if (mess.m_source == VFS_PROC_NR)
{
sr_rec(&mess, ipc_status);
}
else if (is_ipc_notify(ipc_status))
{
if (mess.m_source == CLOCK)
{
clck_tick(&mess);
}
else if (mess.m_source == DS_PROC_NR)
{
/* DS notifies us of an event. */
ds_event();
}
else
{
printf("inet: got unexpected notify from %d\n",
mess.m_source);
}
}
else if (mess.m_type == DL_CONF_REPLY ||
mess.m_type == DL_TASK_REPLY ||
mess.m_type == DL_STAT_REPLY)
{
eth_rec(&mess);
}
else
{
printf("inet: got bad message type 0x%x from %d\n",
mess.m_type, mess.m_source);
}
}
ip_panic(("task is not allowed to terminate"));
return 1;
}
/*===========================================================================*
* sef_local_startup *
*===========================================================================*/
static void sef_local_startup()
{
/* Register init callbacks. */
sef_setcb_init_fresh(sef_cb_init_fresh);
sef_setcb_init_restart(sef_cb_init_fresh);
/* No live update support for now. */
/* Let SEF perform startup. */
sef_startup();
}
/*===========================================================================*
* sef_cb_init_fresh *
*===========================================================================*/
static int sef_cb_init_fresh(int type, sef_init_info_t *info)
{
/* Initialize the inet server. */
int r;
int timerand, fd;
u8_t randbits[32];
struct timeval tv;
#if DEBUG
printf("Starting inet...\n");
printf("%s\n", version);
#endif
#if HZ_DYNAMIC
system_hz = sys_hz();
#endif
/* Read configuration. */
nw_conf();
/* Get a random number */
timerand= 1;
fd= open(RANDOM_DEV_NAME, O_RDONLY | O_NONBLOCK);
if (fd != -1)
{
r= read(fd, randbits, sizeof(randbits));
if (r == sizeof(randbits))
timerand= 0;
else
{
printf("inet: unable to read random data from %s: %s\n",
RANDOM_DEV_NAME, r == -1 ? strerror(errno) :
r == 0 ? "EOF" : "not enough data");
}
close(fd);
}
else
{
printf("inet: unable to open random device %s: %s\n",
RANDOM_DEV_NAME, strerror(errno));
}
if (timerand)
{
printf("inet: using current time for random-number seed\n");
r= gettimeofday(&tv, NULL);
if (r == -1)
{
printf("sysutime failed: %s\n", strerror(errno));
exit(1);
}
memcpy(randbits, &tv, sizeof(tv));
}
init_rand256(randbits);
/* Our new identity as a server. */
this_proc= info->endpoint;
#ifdef BUF_CONSISTENCY_CHECK
inet_buf_debug= (getenv("inetbufdebug") &&
(strcmp(getenv("inetbufdebug"), "on") == 0));
inet_buf_debug= 100;
if (inet_buf_debug)
{
ip_warning(( "buffer consistency check enabled" ));
}
#endif
if (getenv("killerinet"))
{
ip_warning(( "killer inet active" ));
killer_inet= 1;
}
nw_init();
/* Subscribe to driver events for network drivers. */
r = ds_subscribe("drv\\.net\\..*", DSF_INITIAL | DSF_OVERWRITE);
if(r != OK) {
ip_panic(("inet: can't subscribe to driver events"));
}
/* Drop privileges. */
if (setuid(SERVICE_UID) != 0)
printf("inet: warning, unable to drop privileges\n");
/* Announce we are up. INET announces its presence to VFS just like
* any other character driver.
*/
chardriver_announce();
return(OK);
}
static void nw_conf()
{
read_conf();
eth_prep();
arp_prep();
psip_prep();
ip_prep();
tcp_prep();
udp_prep();
}
static void nw_init()
{
mq_init();
bf_init();
clck_init();
sr_init();
qp_init();
eth_init();
arp_init();
psip_init();
ip_init();
tcp_init();
udp_init();
}
/*===========================================================================*
* ds_event *
*===========================================================================*/
static void ds_event()
{
char key[DS_MAX_KEYLEN];
char *driver_prefix = (char *) "drv.net.";
char *label;
u32_t value;
int type;
endpoint_t owner_endpoint;
int r;
int prefix_len;
prefix_len = strlen(driver_prefix);
/* We may get one notification for multiple updates from DS. Get events
* and owners from DS, until DS tells us that there are no more.
*/
while ((r = ds_check(key, &type, &owner_endpoint)) == OK) {
r = ds_retrieve_u32(key, &value);
if(r != OK) {
printf("inet: ds_event: ds_retrieve_u32 failed\n");
return;
}
/* Only check for network driver up events. */
if(strncmp(key, driver_prefix, prefix_len)
|| value != DS_DRIVER_UP) {
return;
}
/* The driver label comes after the prefix. */
label = key + prefix_len;
/* A driver is (re)started. */
eth_check_driver(label, owner_endpoint);
}
if(r != ENOENT)
printf("inet: ds_event: ds_check failed: %d\n", r);
}
void panic0(file, line)
char *file;
int line;
{
printf("panic at %s, %d: ", file, line);
}
__dead
void inet_panic(void)
{
printf("\ninet stacktrace: ");
util_stacktrace();
(panic)("aborted due to a panic");
for(;;);
}
#if !NDEBUG
__dead
void bad_assertion(file, line, what)
char *file;
int line;
char *what;
{
panic0(file, line);
printf("assertion \"%s\" failed", what);
panic("help");
}
__dead
void bad_compare(file, line, lhs, what, rhs)
char *file;
int line;
int lhs;
char *what;
int rhs;
{
panic0(file, line);
printf("compare (%d) %s (%d) failed", lhs, what, rhs);
panic("help");
}
#endif /* !NDEBUG */
/*
* $PchId: inet.c,v 1.23 2005/06/28 14:27:22 philip Exp $
*/