- Also convert to unix abstract socket
- A simple FNV hash is used instead of SHA-1 since we may not HAVE_GNUTLS
Signed-off-by: Dwight Engen <dwight.en...@oracle.com>
---
src/lxc/monitor.c | 60 ++++++++++++++++++++++++++++++++++++-------------------
1 file changed, 40 insertions(+), 20 deletions(-)
diff --git a/src/lxc/monitor.c b/src/lxc/monitor.c
index bdcc581..64e9987 100644
--- a/src/lxc/monitor.c
+++ b/src/lxc/monitor.c
@@ -28,6 +28,8 @@
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
+#include <inttypes.h>
+#include <stdint.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
@@ -123,38 +125,56 @@ int lxc_monitor_close(int fd)
return close(fd);
}
+/* Note we don't use SHA-1 here as we don't want to depend on HAVE_GNUTLS.
+ * FNV has good anti collision properties and we're not worried
+ * about pre-image resistance or one-way-ness, we're just trying to make
+ * the name unique in the 108 bytes of space we have.
+ */
+#define FNV1A_64_INIT ((uint64_t)0xcbf29ce484222325ULL)
+static uint64_t fnv_64a_buf(void *buf, size_t len, uint64_t hval)
+{
+ unsigned char *bp;
+
+ for(bp = buf; bp < (unsigned char *)buf + len; bp++)
+ {
+ /* xor the bottom with the current octet */
+ hval ^= (uint64_t)*bp;
+
+ /* gcc optimised:
+ * multiply by the 64 bit FNV magic prime mod 2^64
+ */
+ hval += (hval << 1) + (hval << 4) + (hval << 5) +
+ (hval << 7) + (hval << 8) + (hval << 40);
+ }
+
+ return hval;
+}
+
int lxc_monitor_sock_name(const char *lxcpath, struct sockaddr_un *addr) {
size_t len;
int ret;
- char *sockname = &addr->sun_path[0]; // 1 for abstract
- const char *rundir;
+ char *sockname = &addr->sun_path[1];
+ char path[PATH_MAX+18];
+ uint64_t hash;
- /* addr.sun_path is only 108 bytes.
- * should we take a hash of lxcpath? a subset of it? ftok()? we need
- * to make sure it is unique.
+ /* addr.sun_path is only 108 bytes, so we hash the full name and
+ * then append as much of the name as we can fit.
*/
memset(addr, 0, sizeof(*addr));
addr->sun_family = AF_UNIX;
len = sizeof(addr->sun_path) - 1;
- rundir = get_rundir();
- ret = snprintf(sockname, len, "%s/lxc/%s", rundir, lxcpath);
- if (ret < 0 || ret >= len) {
- ERROR("rundir/lxcpath (%s/%s) too long for monitor unix
socket", rundir, lxcpath);
+ ret = snprintf(path, sizeof(path), "lxc/%s/monitor-sock", lxcpath);
+ if (ret < 0 || ret >= sizeof(path)) {
+ ERROR("lxcpath %s too long for monitor unix socket", lxcpath);
return -1;
}
- process_lock();
- ret = mkdir_p(sockname, 0755);
- process_unlock();
- if (ret < 0) {
- ERROR("unable to create monitor sock %s", sockname);
- return ret;
- }
- ret = snprintf(sockname, len, "%s/lxc/%s/monitor-sock", rundir,
lxcpath);
- if (ret < 0 || ret >= len) {
- ERROR("rundir/lxcpath (%s/%s) too long for monitor unix
socket", rundir, lxcpath);
+ hash = fnv_64a_buf(path, ret, FNV1A_64_INIT);
+ ret = snprintf(sockname, len, "lxc/%016" PRIx64 "/%s", hash, lxcpath);
+ if (ret < 0)
return -1;
- }
+ sockname[sizeof(addr->sun_path)-2] = '\0';
+ INFO("using monitor sock name %s", sockname);
return 0;
}
--
1.8.1.4
------------------------------------------------------------------------------
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