1 files changed, 127 insertions, 84 deletions

diff --git a/srcx/util.c b/srcx/util.c
index 8894c61..ffea8ff 100644
--- a/srcx/util.c
+++ b/srcx/util.c
@@ -57,112 +57,155 @@
 #include <string.h>
 #include <unistd.h>
 
+#include <netinet/in.h>
+
 #include "util.h"
 
 extern char** environ;
 
-size_t get_jail_sysctl(struct xprison** ret)
+void
+jails_load (jails *jls)
 {
-    struct xprison* xp;
-    size_t len;
-    *ret = NULL;
-
-    if(sysctlbyname("security.jail.list", NULL, &len, NULL, 0) == -1)
-      err(1, "couldn't list jails");
-
-retry:
+	struct xprison *xp;
 
-    if(len <= 0)
-        return 0;
-
-    xp = calloc(len, 1);
-    if(xp == NULL)
-        err(1, "out of memory");
-
-    if(sysctlbyname("security.jail.list", xp, &len, NULL, 0) == -1)
-    {
-        if(errno == ENOMEM)
-        {
-            free(xp);
-            goto retry;
-        }
+	memset (jls, 0, sizeof (jails));
 
-        err(1, "couldn't list jails");
-    }
+	if(sysctlbyname("security.jail.list", NULL, &jls->length, NULL, 0) == -1)
+		err(1, "couldn't list jails");
 
-    if(len < sizeof(*xp) || len % sizeof(*xp) || xp->pr_version != XPRISON_VERSION)
-        errx(1, "kernel and userland out of sync");
+retry:
 
-    *ret = xp;
-    return len / sizeof(*xp);
+	if(jls->length <= 0)
+	{
+		jls->data = NULL;
+		jls->last = NULL;
+	}
+
+	jls->data = calloc(jls->length, 1);
+	if(jls->data == NULL)
+		err(1, "out of memory");
+
+	if(sysctlbyname("security.jail.list", jls->data, &jls->length, NULL, 0) == -1)
+	{
+		if(errno == ENOMEM)
+		{
+			free(jls->data);
+			jls->data = NULL;
+			goto retry;
+		}
+
+		err(1, "couldn't list jails");
+	}
+
+	xp = jls->data;
+	if(jls->length < sizeof(*xp) || xp->pr_version != XPRISON_VERSION)
+		errx(1, "kernel and userland out of sync");
 }
 
-void free_jail_sysctl(size_t len, struct xprison* xp)
+struct xprison*
+jails_next (jails *jls)
 {
-    if(len == 0 || xp == NULL)
-        return;
-
-    /*
-     * An extra precaution to prevent leakage of information
-     * into the jail.
-     */
-
-    memset(xp, 0, sizeof(struct xprison) * len);
-    free(xp);
+	struct xprison *xp = jls->last;
+	unsigned char *data, *next, *end;
+
+	if(xp == NULL)
+	{
+		xp = jls->data;
+	}
+	else
+	{
+		switch(xp->pr_version)
+		{
+		case 1:
+		case 2:
+			xp = xp + 1;
+			break;
+		case 3:
+			data = (unsigned char*)(xp + 1);
+			data += (xp->pr_ip4s * sizeof(struct in_addr));
+			data += (xp->pr_ip6s * sizeof(struct in6_addr));
+			xp = (struct xprison*)data;
+			break;
+		default:
+			errx(1, "unknown jail structure");
+			break;
+		}
+	}
+
+	if(xp == NULL)
+		return NULL;
+
+	next = (unsigned char*)(xp + 1);
+	end = ((unsigned char*)jls->data) + jls->length;
+	if (next > end)
+		return NULL;
+
+	if(xp->pr_version != XPRISON_VERSION)
+		errx(1, "kernel and userland out of sync");
+
+	jls->last = xp;
+	return xp;
 }
 
-struct xprison* find_jail(const char* str, size_t len, struct xprison* xp)
+void
+jails_done(jails *jls)
 {
-    int jid;
-    size_t i;
-    char* e;
-
-    if(len == 0 || xp == NULL)
-        return NULL;
-
-    jid = strtol(str, &e, 10);
-
-    /* If it was all a number ... */
-    if(!*e)
-    {
-        if(jid <= 0)
-            errx(1, "invalid jail id: %s", str);
-
-        /* Validate the number */
-        for(i = 0; i < len; i++)
-        {
-            if(jid == xp[i].pr_id)
-                return &(xp[i]);
-        }
-    }
-
-    for(i = 0; i < len; i++)
-    {
-        if(strcmp(xp[i].pr_host, str) == 0)
-            return &(xp[i]);
-    }
+	memset(jls->data, 0, jls->length);
+	free(jls->data);
+	jls->data = NULL;
+	jls->length = 0;
+	jls->last = NULL;
+}
 
-    return NULL;
+struct xprison*
+jails_find(jails *jls, const char* str)
+{
+	struct xprison *xp;
+	char *e;
+	int jid;
+
+	jid = strtol(str, &e, 10);
+	jls->last = NULL;
+
+	for(;;)
+	{
+		xp = jails_next(jls);
+		if(xp == NULL)
+			return NULL;
+
+		/* If it was all a number ... */
+		if(!*e)
+		{
+			if(jid <= 0)
+				errx(1, "invalid jail id: %s", str);
+			if(jid == xp->pr_id)
+				return xp;
+		}
+
+		/* A host name? */
+		else
+		{
+			if(strcmp(xp->pr_host, str) == 0)
+				return xp;
+		}
+	}
+
+	/* Not reached */
 }
 
 int translate_jail_name(const char* str)
 {
-    struct xprison* sxp = NULL;
-    struct xprison* xp = NULL;
-    size_t len;
-    int jid = -1;
-
-    len = get_jail_sysctl(&sxp);
-    if(sxp)
-    {
-        xp = find_jail(str, len, sxp);
-        if(xp != NULL)
-            jid = xp->pr_id;
+	struct xprison* xp;
+	int jid = -1;
+	jails jls;
 
-        free(sxp);
-    }
+	jails_load(&jls);
+	xp = jails_find(&jls, str);
+	if(xp != NULL)
+		jid = xp->pr_id;
+	jails_done(&jls);
 
-    return jid;
+	return jid;
 }
 
 int kvm_prepare_jail(struct xprison* xp)