Small tweaks

Lots of new code imported.

src/cmd/factotum/plan9.c

@@ -0,0 +1,189 @@
+#include "std.h"
+#include "dat.h"
+#include <bio.h>
+
+int
+memrandom(void *p, int n)
+{
+	uchar *cp;
+
+	for(cp = (uchar*)p; n > 0; n--)
+		*cp++ = fastrand();
+	return 0;
+}
+
+/*
+ *  create a change uid capability 
+ */
+static int caphashfd;
+
+static char*
+mkcap(char *from, char *to)
+{
+	uchar rand[20];
+	char *cap;
+	char *key;
+	int nfrom, nto;
+	uchar hash[SHA1dlen];
+
+	if(caphashfd < 0)
+		return nil;
+
+	/* create the capability */
+	nto = strlen(to);
+	nfrom = strlen(from);
+	cap = emalloc(nfrom+1+nto+1+sizeof(rand)*3+1);
+	sprint(cap, "%s@%s", from, to);
+	memrandom(rand, sizeof(rand));
+	key = cap+nfrom+1+nto+1;
+	enc64(key, sizeof(rand)*3, rand, sizeof(rand));
+
+	/* hash the capability */
+	hmac_sha1((uchar*)cap, strlen(cap), (uchar*)key, strlen(key), hash, nil);
+
+	/* give the kernel the hash */
+	key[-1] = '@';
+	if(write(caphashfd, hash, SHA1dlen) < 0){
+		free(cap);
+		return nil;
+	}
+
+	return cap;
+}
+
+Attr*
+addcap(Attr *a, char *from, Ticket *t)
+{
+	char *cap;
+
+	cap = mkcap(from, t->suid);
+	return addattr(a, "cuid=%q suid=%q cap=%q", t->cuid, t->suid, cap);
+}
+
+/* bind in the default network and cs */
+static int
+bindnetcs(void)
+{
+	int srvfd;
+
+	if(access("/net/tcp", AEXIST) < 0)
+		bind("#I", "/net", MBEFORE);
+
+	if(access("/net/cs", AEXIST) < 0){
+		if((srvfd = open("#s/cs", ORDWR)) >= 0){
+			/* mount closes srvfd on success */
+			if(mount(srvfd, -1, "/net", MBEFORE, "") >= 0)
+				return 0;
+			close(srvfd);
+		}
+		return -1;
+	}
+	return 0;
+}
+
+int
+_authdial(char *net, char *authdom)
+{
+	int vanilla;
+
+	vanilla = net==nil || strcmp(net, "/net")==0;
+
+	if(!vanilla || bindnetcs()>=0)
+		return authdial(net, authdom);
+
+	/* use the auth sever passed to us as an arg */
+	if(authaddr == nil)
+		return -1;
+	return dial(netmkaddr(authaddr, "tcp", "567"), 0, 0, 0);
+}
+
+Key*
+plan9authkey(Attr *a)
+{
+	char *dom;
+	Key *k;
+
+	/*
+	 * The only important part of a is dom.
+	 * We don't care, for example, about user name.
+	 */
+	dom = strfindattr(a, "dom");
+	if(dom)
+		k = keylookup("proto=p9sk1 role=server user? dom=%q", dom);
+	else
+		k = keylookup("proto=p9sk1 role=server user? dom?");
+	if(k == nil)
+		werrstr("could not find plan 9 auth key dom %q", dom);
+	return k;
+}
+
+/*
+ *  prompt for a string with a possible default response
+ */
+char*
+readcons(char *prompt, char *def, int raw)
+{
+	int fdin, fdout, ctl, n;
+	char line[10];
+	char *s;
+
+	fdin = open("/dev/cons", OREAD);
+	if(fdin < 0)
+		fdin = 0;
+	fdout = open("/dev/cons", OWRITE);
+	if(fdout < 0)
+		fdout = 1;
+	if(def != nil)
+		fprint(fdout, "%s[%s]: ", prompt, def);
+	else
+		fprint(fdout, "%s: ", prompt);
+	if(raw){
+		ctl = open("/dev/consctl", OWRITE);
+		if(ctl >= 0)
+			write(ctl, "rawon", 5);
+	} else
+		ctl = -1;
+	s = estrdup("");
+	for(;;){
+		n = read(fdin, line, 1);
+		if(n == 0){
+		Error:
+			close(fdin);
+			close(fdout);
+			if(ctl >= 0)
+				close(ctl);
+			free(s);
+			return nil;
+		}
+		if(n < 0)
+			goto Error;
+		if(line[0] == 0x7f)
+			goto Error;
+		if(n == 0 || line[0] == '\n' || line[0] == '\r'){
+			if(raw){
+				write(ctl, "rawoff", 6);
+				write(fdout, "\n", 1);
+			}
+			close(ctl);
+			close(fdin);
+			close(fdout);
+			if(*s == 0 && def != nil)
+				s = estrappend(s, "%s", def);
+			return s;
+		}
+		if(line[0] == '\b'){
+			if(strlen(s) > 0)
+				s[strlen(s)-1] = 0;
+		} else if(line[0] == 0x15) {	/* ^U: line kill */
+			if(def != nil)
+				fprint(fdout, "\n%s[%s]: ", prompt, def);
+			else
+				fprint(fdout, "\n%s: ", prompt);
+			
+			s[0] = 0;
+		} else {
+			s = estrappend(s, "%c", line[0]);
+		}
+	}
+	return nil; /* not reached */
+}