1 files changed, 322 insertions, 0 deletions
diff --git a/src/libauth/newns.c b/src/libauth/newns.c
new file mode 100644
index 00000000..66f51d37
--- /dev/null
+++ b/src/libauth/newns.c
@@ -0,0 +1,322 @@
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+#include <auth.h>
+#include <authsrv.h>
+#include "authlocal.h"
+
+enum
+{
+	NARG	= 15,		/* max number of arguments */
+	MAXARG	= 10*ANAMELEN,	/* max length of an argument */
+};
+
+static int	setenv(char*, char*);
+static char	*expandarg(char*, char*);
+static int	splitargs(char*, char*[], char*, int);
+static int	nsfile(Biobuf *, AuthRpc *);
+static int	nsop(int, char*[], AuthRpc*);
+static int	callexport(char*, char*);
+static int	catch(void*, char*);
+
+static int
+buildns(int newns, char *user, char *file)
+{
+	Biobuf *b;
+	char home[4*ANAMELEN];
+	int afd;
+	AuthRpc *rpc;
+	int cdroot;
+	char *path;
+
+	rpc = nil;
+	/* try for factotum now because later is impossible */
+	afd = open("/mnt/factotum/rpc", ORDWR);
+	if(afd >= 0){
+		rpc = auth_allocrpc(afd);
+		if(rpc == nil){
+			close(afd);
+			afd = -1;
+		}
+	}
+	if(file == nil){
+		if(!newns){
+			werrstr("no namespace file specified");
+			return -1;
+		}
+		file = "/lib/namespace";
+	}
+	b = Bopen(file, OREAD);
+	if(b == 0){
+		werrstr("can't open %s: %r", file);
+		close(afd);
+		auth_freerpc(rpc);
+		return -1;
+	}
+	if(newns){
+		rfork(RFENVG|RFCNAMEG);
+		setenv("user", user);
+		snprint(home, 2*ANAMELEN, "/usr/%s", user);
+		setenv("home", home);
+	}
+	cdroot = nsfile(b, rpc);
+	Bterm(b);
+	if(rpc){
+		close(rpc->afd);
+		auth_freerpc(rpc);
+	}
+
+	/* make sure we managed to cd into the new name space */
+	if(newns && !cdroot){
+		path = malloc(1024);
+		if(path == nil || getwd(path, 1024) == 0 || chdir(path) < 0)
+			chdir("/");
+		if(path != nil)
+			free(path);
+	}
+
+	return 0;
+}
+
+static int
+nsfile(Biobuf *b, AuthRpc *rpc)
+{
+	int argc;
+	char *cmd, *argv[NARG+1], argbuf[MAXARG*NARG];
+	int cdroot = 0;
+
+	atnotify(catch, 1);
+	while(cmd = Brdline(b, '\n')){
+		cmd[Blinelen(b)-1] = '\0';
+		while(*cmd==' ' || *cmd=='\t')
+			cmd++;
+		if(*cmd == '#')
+			continue;
+		argc = splitargs(cmd, argv, argbuf, NARG);
+		if(argc)
+			cdroot |= nsop(argc, argv, rpc);
+	}
+	atnotify(catch, 0);
+	return cdroot;
+}
+
+int
+newns(char *user, char *file)
+{
+	return buildns(1, user, file);
+}
+
+int
+addns(char *user, char *file)
+{
+	return buildns(0, user, file);
+}
+
+static int
+famount(int fd, AuthRpc *rpc, char *mntpt, int flags, char *aname)
+{
+	int afd;
+	AuthInfo *ai;
+
+	afd = fauth(fd, aname);
+	if(afd >= 0){
+		ai = fauth_proxy(afd, rpc, amount_getkey, "proto=p9any role=client");
+		if(ai != nil)
+			auth_freeAI(ai);
+	}
+	return mount(fd, afd, mntpt, flags, aname);
+}
+
+static int
+nsop(int argc, char *argv[], AuthRpc *rpc)
+{
+	char *argv0;
+	ulong flags;
+	int fd;
+	Biobuf *b;
+	int cdroot = 0;
+
+	flags = 0;
+	argv0 = 0;
+	ARGBEGIN{
+	case 'a':
+		flags |= MAFTER;
+		break;
+	case 'b':
+		flags |= MBEFORE;
+		break;
+	case 'c':
+		flags |= MCREATE;
+		break;
+	case 'C':
+		flags |= MCACHE;
+		break;
+	}ARGEND
+
+	if(!(flags & (MAFTER|MBEFORE)))
+		flags |= MREPL;
+
+	if(strcmp(argv0, ".") == 0 && argc == 1){
+		b = Bopen(argv[0], OREAD);
+		if(b == nil)
+			return 0;
+		cdroot |= nsfile(b, rpc);
+		Bterm(b);
+	} else if(strcmp(argv0, "clear") == 0 && argc == 0)
+		rfork(RFCNAMEG);
+	else if(strcmp(argv0, "bind") == 0 && argc == 2)
+		bind(argv[0], argv[1], flags);
+	else if(strcmp(argv0, "unmount") == 0){
+		if(argc == 1)
+			unmount(nil, argv[0]);
+		else if(argc == 2)
+			unmount(argv[0], argv[1]);
+	} else if(strcmp(argv0, "mount") == 0){
+		fd = open(argv[0], ORDWR);
+		if(argc == 2)
+			famount(fd, rpc, argv[1], flags, "");
+		else if(argc == 3)
+			famount(fd, rpc, argv[1], flags, argv[2]);
+		close(fd);
+	} else if(strcmp(argv0, "import") == 0){
+		fd = callexport(argv[0], argv[1]);
+		if(argc == 2)
+			famount(fd, rpc, argv[1], flags, "");
+		else if(argc == 3)
+			famount(fd, rpc, argv[2], flags, "");
+		close(fd);
+	} else if(strcmp(argv0, "cd") == 0 && argc == 1)
+		if(chdir(argv[0]) == 0 && *argv[0] == '/')
+			cdroot = 1;
+	return cdroot;
+}
+
+static char *wocp = "sys: write on closed pipe";
+
+static int
+catch(void *x, char *m)
+{
+	USED(x);
+	return strncmp(m, wocp, strlen(wocp)) == 0;
+}
+
+static int
+callexport(char *sys, char *tree)
+{
+	char *na, buf[3];
+	int fd;
+	AuthInfo *ai;
+
+	na = netmkaddr(sys, 0, "exportfs");
+	if((fd = dial(na, 0, 0, 0)) < 0)
+		return -1;
+	if((ai = auth_proxy(fd, auth_getkey, "proto=p9any role=client")) == nil
+	|| write(fd, tree, strlen(tree)) < 0
+	|| read(fd, buf, 3) != 2 || buf[0]!='O' || buf[1]!= 'K'){
+		close(fd);
+		auth_freeAI(ai);
+		return -1;
+	}
+	auth_freeAI(ai);
+	return fd;
+}
+
+static int
+splitargs(char *p, char *argv[], char *argbuf, int nargv)
+{
+	char *q;
+	int i, n;
+
+	n = gettokens(p, argv, nargv, " \t'\r");
+	if(n == nargv)
+		return 0;
+	for(i = 0; i < n; i++){
+		q = argv[i];
+		argv[i] = argbuf;
+		argbuf = expandarg(q, argbuf);
+		if(!argbuf)
+			return 0;
+	}
+	return n;
+}
+
+/*
+ * copy the arg into the buffer,
+ * expanding any environment variables.
+ * environment variables are assumed to be
+ * names (ie. < ANAMELEN long)
+ * the entire argument is expanded to be at
+ * most MAXARG long and null terminated
+ * the address of the byte after the terminating null is returned
+ * any problems cause a 0 return;
+ */
+static char *
+expandarg(char *arg, char *buf)
+{
+	char env[3+ANAMELEN], *p, *q, *x;
+	int fd, n, len;
+
+	n = 0;
+	while(p = utfrune(arg, L'$')){
+		len = p - arg;
+		if(n + len + ANAMELEN >= MAXARG-1)
+			return 0;
+		memmove(&buf[n], arg, len);
+		n += len;
+		p++;
+		arg = utfrune(p, L'\0');
+		q = utfrune(p, L'/');
+		if(q && q < arg)
+			arg = q;
+		q = utfrune(p, L'.');
+		if(q && q < arg)
+			arg = q;
+		q = utfrune(p, L'$');
+		if(q && q < arg)
+			arg = q;
+		len = arg - p;
+		if(len >= ANAMELEN)
+			continue;
+		strcpy(env, "#e/");
+		strncpy(env+3, p, len);
+		env[3+len] = '\0';
+		fd = open(env, OREAD);
+		if(fd >= 0){
+			len = read(fd, &buf[n], ANAMELEN - 1);
+			/* some singleton environment variables have trailing NULs */
+			/* lists separate entries with NULs; we arbitrarily take the first element */
+			if(len > 0){
+				x = memchr(&buf[n], 0, len);
+				if(x != nil)
+					len = x - &buf[n];
+				n += len;
+			}
+			close(fd);
+		}
+	}
+	len = strlen(arg);
+	if(n + len >= MAXARG - 1)
+		return 0;
+	strcpy(&buf[n], arg);
+	return &buf[n+len+1];
+}
+
+static int
+setenv(char *name, char *val)
+{
+	int f;
+	char ename[ANAMELEN+6];
+	long s;
+
+	sprint(ename, "#e/%s", name);
+	f = create(ename, OWRITE, 0664);
+	if(f < 0)
+		return -1;
+	s = strlen(val);
+	if(write(f, val, s) != s){
+		close(f);
+		return -1;
+	}
+	close(f);
+	return 0;
+}