NetBSD/libexec/identd/netbsd.c

246 lines
4.8 KiB
C

/* $NetBSD: netbsd.c,v 1.11 1997/10/08 07:24:51 mrg Exp $ */
/*
** netbsd.c Low level kernel access functions for NetBSD
**
** This program is in the public domain and may be used freely by anyone
** who wants to.
**
** Last update: 17 March 1993
**
** Please send bug fixes/bug reports to: Peter Eriksson <pen@lysator.liu.se>
*/
#include <stdio.h>
#include <errno.h>
#include <ctype.h>
#include <limits.h>
#include <nlist.h>
#include <pwd.h>
#include <signal.h>
#include <syslog.h>
#include <stdlib.h>
#include "kvm.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#define _KERNEL
#include <sys/file.h>
#undef _KERNEL
#include <sys/sysctl.h>
#include <fcntl.h>
#include <sys/user.h>
#include <sys/wait.h>
#include <net/if.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet/tcp.h>
#include <netinet/ip_var.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>
#include <arpa/inet.h>
#include "identd.h"
#include "error.h"
struct nlist nl[] =
{
#define N_FILE 0
#define N_NFILE 1
#define N_TCBTABLE 2
{ "_filehead" },
{ "_nfiles" },
{ "_tcbtable" },
{ "" }
};
static kvm_t *kd;
static struct file *xfile;
static int nfile;
static struct inpcbtable tcbtable;
static int getbuf __P((long, char *, int, char *));
static struct socket *getlist __P((struct inpcbtable *, struct inpcbtable *,
struct in_addr *, int, struct in_addr *, int));
int k_open()
{
char errbuf[_POSIX2_LINE_MAX];
/*
** Open the kernel memory device
*/
if ((kd = kvm_openfiles(path_unix, path_kmem, NULL, O_RDONLY, errbuf)) ==
NULL)
ERROR1("main: kvm_open: %s", errbuf);
/*
** Extract offsets to the needed variables in the kernel
*/
if (kvm_nlist(kd, nl) < 0)
ERROR("main: kvm_nlist");
return 0;
}
/*
** Get a piece of kernel memory with error handling.
** Returns 1 if call succeeded, else 0 (zero).
*/
static int getbuf(addr, buf, len, what)
long addr;
char *buf;
int len;
char *what;
{
if (kvm_read(kd, addr, buf, len) < 0)
{
if (syslog_flag)
syslog(LOG_ERR, "getbuf: kvm_read(%#lx, %d) - %s : %m",
addr, len, what);
return 0;
}
return 1;
}
/*
** Traverse the inpcb list until a match is found.
** Returns NULL if no match.
*/
static struct socket *
getlist(tcbtablep, ktcbtablep, faddr, fport, laddr, lport)
struct inpcbtable *tcbtablep, *ktcbtablep;
struct in_addr *faddr;
int fport;
struct in_addr *laddr;
int lport;
{
struct inpcb *kpcbp, pcb;
if (!tcbtablep)
return NULL;
for (kpcbp = tcbtablep->inpt_queue.cqh_first;
kpcbp != (struct inpcb *)ktcbtablep;
kpcbp = pcb.inp_queue.cqe_next) {
if (!getbuf((long)kpcbp, (char *)&pcb, sizeof(struct inpcb),
"tcb"))
break;
if (pcb.inp_faddr.s_addr == faddr->s_addr &&
pcb.inp_laddr.s_addr == laddr->s_addr &&
pcb.inp_fport == fport &&
pcb.inp_lport == lport )
return pcb.inp_socket;
}
return NULL;
}
/*
** Return the user number for the connection owner
*/
int k_getuid(faddr, fport, laddr, lport, uid)
struct in_addr *faddr;
int fport;
struct in_addr *laddr;
int lport;
int *uid;
{
long addr;
struct socket *sockp;
int i, mib[2];
struct ucred ucb;
/* -------------------- FILE DESCRIPTOR TABLE -------------------- */
if (!getbuf(nl[N_NFILE].n_value, (char *)&nfile, sizeof(nfile), "nfile"))
return -1;
if (!getbuf(nl[N_FILE].n_value, (char *)&addr, sizeof(addr), "&file"))
return -1;
{
size_t siz;
int rv;
mib[0] = CTL_KERN;
mib[1] = KERN_FILE;
if ((rv = sysctl(mib, 2, NULL, &siz, NULL, 0)) == -1)
{
ERROR1("k_getuid: sysctl 1 (%d)", rv);
return -1;
}
xfile = malloc(siz);
if (!xfile)
ERROR1("k_getuid: malloc(%ld)", (u_long)siz);
if ((rv = sysctl(mib, 2, xfile, &siz, NULL, 0)) == -1)
{
ERROR1("k_getuid: sysctl 2 (%d)", rv);
return -1;
}
xfile = (struct file *)((char *)xfile + sizeof(filehead));
}
/* -------------------- TCP PCB LIST -------------------- */
if (!getbuf(nl[N_TCBTABLE].n_value, (char *)&tcbtable, sizeof(tcbtable),
"tcbtable"))
return -1;
sockp = getlist(&tcbtable, (struct inpcbtable *)nl[N_TCBTABLE].n_value,
faddr, fport, laddr, lport);
if (!sockp)
return -1;
/*
** Locate the file descriptor that has the socket in question
** open so that we can get the 'ucred' information
*/
for (i = 0; i < nfile; i++)
{
if (xfile[i].f_count == 0)
continue;
if (xfile[i].f_type == DTYPE_SOCKET &&
(struct socket *) xfile[i].f_data == sockp)
{
if (!getbuf((long)xfile[i].f_cred, (char *)&ucb, sizeof(ucb), "ucb"))
return -1;
*uid = ucb.cr_uid;
return 0;
}
}
return -1;
}