A long enough lxcpath (and small PATH_MAX through crappy defines) can cause
the creation of the string to be hashed to fail. So just use alloca to
get the size string we need.
More importantly, while I can't explain it, if lxcpath is too long, setting
sockname[sizeof(addr->sun_path)-2] to \0 simply doesn't seem to work. So set
sockname[sizeof(addr->sun_path)-3] to \0, which does work.
With this, and with
lxc.lxcpath =
/opt/lxc0123456789/lxc0123456789/lxc0123456789/lxc0123456789/lxc0123456789/lxc0123456789/lxc0123456789/lxc0123456789/lxc0123456789/lxc0123456789
in /etc/lxc/lxc.conf, I can run lxc-wait just fine. Without it, it fails
(as does lxc-start -d, which uses lxc_wait to verify the container started)
Signed-off-by: Serge Hallyn <serge.hal...@ubuntu.com>
---
src/lxc/monitor.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/src/lxc/monitor.c b/src/lxc/monitor.c
index 7c6dbb4..59b02b3 100644
--- a/src/lxc/monitor.c
+++ b/src/lxc/monitor.c
@@ -142,7 +142,7 @@ int lxc_monitor_sock_name(const char *lxcpath, struct
sockaddr_un *addr) {
size_t len;
int ret;
char *sockname = &addr->sun_path[1];
- char path[PATH_MAX+18];
+ char *path;
uint64_t hash;
/* addr.sun_path is only 108 bytes, so we hash the full name and
@@ -150,18 +150,20 @@ int lxc_monitor_sock_name(const char *lxcpath, struct
sockaddr_un *addr) {
*/
memset(addr, 0, sizeof(*addr));
addr->sun_family = AF_UNIX;
- len = sizeof(addr->sun_path) - 1;
- 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);
+ len = strlen(lxcpath) + 18;
+ path = alloca(len);
+ ret = snprintf(path, len, "lxc/%s/monitor-sock", lxcpath);
+ if (ret < 0 || ret >= len) {
+ ERROR("memory error creating monitor path");
return -1;
}
+ len = sizeof(addr->sun_path) - 1;
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';
+ sockname[sizeof(addr->sun_path)-3] = '\0';
INFO("using monitor sock name %s", sockname);
return 0;
}
--
2.1.0.rc1
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