kern/src/net/nixip/netlog.c

#include <vfs.h>
#include <kfs.h>
#include <slab.h>
#include <kmalloc.h>
#include <kref.h>
#include <string.h>
#include <stdio.h>
#include <assert.h>
#include <error.h>
#include <cpio.h>
#include <pmap.h>
#include <smp.h>

enum {
	Nlog = 16 * 1024,
};

/*
 *  action log
 */
struct netlog {
	spinlock_t rwlock;
	int opens;
	char *buf;
	char *end;
	char *rptr;
	int len;

	int logmask;				/* mask of things to debug */
	uint8_t iponly[IPaddrlen];	/* ip address to print debugging for */
	int iponlyset;

	qlock_t qlock;
	struct rendez rv;
};

struct netlogflag {
	char *name;
	int mask;
};

static struct netlogflag flags[] = {
	{"ppp", Logppp,},
	{"ip", Logip,},
	{"fs", Logfs,},
	{"tcp", Logtcp,},
	{"icmp", Logicmp,},
	{"udp", Logudp,},
	{"compress", Logcompress,},
	{"gre", Loggre,},
	{"tcpwin", Logtcp | Logtcpwin,},
	{"tcprxmt", Logtcp | Logtcprxmt,},
	{"udpmsg", Logudp | Logudpmsg,},
	{"ipmsg", Logip | Logipmsg,},
	{"esp", Logesp,},
	{NULL, 0,},
};

char Ebadnetctl[] = "too few arguments for netlog control message";

enum {
	CMset,
	CMclear,
	CMonly,
};

static
struct cmdtab routecmd[] = {
	{CMset, "set", 0},
	{CMclear, "clear", 0},
	{CMonly, "only", 0},
};

void netloginit(struct fs *f)
{
	f->alog = kzmalloc(sizeof(struct netlog), 0);
	rendez_init(&f->alog->rv);
	qlock_init(&f->alog->qlock);
}

void netlogopen(struct fs *f)
{
	ERRSTACK(2);
	spin_lock(&f->alog->rwlock);
	if (waserror()) {
		spin_unlock(&f->alog->rwlock);
		nexterror();
	}
	if (f->alog->opens == 0) {
		if (f->alog->buf == NULL)
			f->alog->buf = kzmalloc(Nlog, 0);
		if (f->alog->buf == NULL)
			error(Enomem);
		f->alog->rptr = f->alog->buf;
		f->alog->end = f->alog->buf + Nlog;
	}
	f->alog->opens++;
	spin_unlock(&f->alog->rwlock);
	poperror();
}

void netlogclose(struct fs *f)
{
	ERRSTACK(2);
	spin_lock(&f->alog->rwlock);
	if (waserror()) {
		spin_unlock(&f->alog->rwlock);
		nexterror();
	}
	f->alog->opens--;
	if (f->alog->opens == 0) {
		kfree(f->alog->buf);
		f->alog->buf = NULL;
	}
	spin_unlock(&f->alog->rwlock);
	poperror();
}

static int netlogready(void *a)
{
	struct fs *f = a;

	return f->alog->len;
}

long netlogread(struct fs *f, void *a, uint32_t unused_len, long n)
{
	ERRSTACK(2);
	int i, d;
	char *p, *rptr;

	qlock(&f->alog->qlock);
	if (waserror()) {
		qunlock(&f->alog->qlock);
		nexterror();
	}

	for (;;) {
		spin_lock(&f->alog->rwlock);
		if (f->alog->len) {
			if (n > f->alog->len)
				n = f->alog->len;
			d = 0;
			rptr = f->alog->rptr;
			f->alog->rptr += n;
			if (f->alog->rptr >= f->alog->end) {
				d = f->alog->rptr - f->alog->end;
				f->alog->rptr = f->alog->buf + d;
			}
			f->alog->len -= n;
			spin_unlock(&f->alog->rwlock);

			i = n - d;
			p = a;
			memmove(p, rptr, i);
			memmove(p + i, f->alog->buf, d);
			break;
		} else
			spin_unlock(&f->alog->rwlock);

		rendez_sleep(&f->alog->rv, netlogready, f);
	}

	qunlock(&f->alog->qlock);
	poperror();

	return n;
}

void netlogctl(struct fs *f, char *s, int n)
{
	ERRSTACK(2);
	int i, set = 0;
	struct netlogflag *fp;
	struct cmdbuf *cb;
	struct cmdtab *ct;

	cb = parsecmd(s, n);
	if (waserror()) {
		kfree(cb);
		nexterror();
	}

	if (cb->nf < 2)
		error(Ebadnetctl);

	ct = lookupcmd(cb, routecmd, ARRAY_SIZE(routecmd));

	switch (ct->index) {
		case CMset:
			set = 1;
			break;

		case CMclear:
			set = 0;
			break;

		case CMonly:
			parseip(f->alog->iponly, cb->f[1]);
			if (ipcmp(f->alog->iponly, IPnoaddr) == 0)
				f->alog->iponlyset = 0;
			else
				f->alog->iponlyset = 1;
			kfree(cb);
			poperror();
			return;

		default:
			cmderror(cb, "unknown netlog control message");
	}

	for (i = 1; i < cb->nf; i++) {
		for (fp = flags; fp->name; fp++)
			if (strcmp(fp->name, cb->f[i]) == 0)
				break;
		if (fp->name == NULL)
			continue;
		if (set)
			f->alog->logmask |= fp->mask;
		else
			f->alog->logmask &= ~fp->mask;
	}

	kfree(cb);
	poperror();
}

void netlog(struct fs *f, int mask, char *fmt, ...)
{
	char buf[256], *t, *fp;
	int i, n;
	va_list arg;

	if (!(f->alog->logmask & mask))
		return;

	if (f->alog->opens == 0)
		return;

	va_start(arg, fmt);
	n = vsnprintf(buf, sizeof(buf), fmt, arg);
	va_end(arg);

	spin_lock(&f->alog->rwlock);
	i = f->alog->len + n - Nlog;
	if (i > 0) {
		f->alog->len -= i;
		f->alog->rptr += i;
		if (f->alog->rptr >= f->alog->end)
			f->alog->rptr = f->alog->buf + (f->alog->rptr - f->alog->end);
	}
	t = f->alog->rptr + f->alog->len;
	fp = buf;
	f->alog->len += n;
	while (n-- > 0) {
		if (t >= f->alog->end)
			t = f->alog->buf + (t - f->alog->end);
		*t++ = *fp++;
	}
	spin_unlock(&f->alog->rwlock);

	rendez_wakeup(&f->alog->rv);
}