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netmgr:

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- make tcp listening IPC pipe name saner
 - put the pipe in /tmp on unices
 - add pid to the pipe name to avoid conflicts between processes
 - fsync directory in which the pipe resides to make sure that the
   child threads will see it and be able to open it
This commit is contained in:
Witold Kręcicki
2019-12-03 19:48:10 +01:00
parent b05194160b
commit 0bf74ac792
3 changed files with 41 additions and 11 deletions
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2
lib/isc/netmgr/netmgr-int.h
View File

@@ -339,7 +339,7 @@ struct isc_nmsocket {
/*% Used to transfer listening TCP sockets to children */
uv_pipe_t ipc;
char ipc_pipe_name[32];
char ipc_pipe_name[64];
atomic_int_fast32_t schildren;
/*% Extra data allocated at the end of each isc_nmhandle_t */

18
lib/isc/netmgr/netmgr.c
View File

@@ -44,9 +44,9 @@
ISC_THREAD_LOCAL int isc__nm_tid_v = ISC_NETMGR_TID_UNKNOWN;
#ifdef WIN32
#define NAMED_PIPE_PREFIX "\\\\.\\pipe\\named-ipc"
#define NAMED_PIPE_PATTERN "\\\\.\\pipe\\named-%d-%u.pipe"
#else
#define NAMED_PIPE_PREFIX ".named-ipc"
#define NAMED_PIPE_PATTERN "/tmp/named-%d-%u.pipe"
#endif
static void
@@ -840,14 +840,14 @@ isc__nmsocket_init(isc_nmsocket_t *sock, isc_nm_t *mgr,
}
/*
* XXXWPK Maybe it should be in tmp, maybe it should not
* be random?
* Use a random number in the named pipe name. Also add getpid()
* to the name to make sure we don't get a conflict between
* different unit tests running at the same time, where the PRNG
* is initialized to a constant seed.
*/
strcpy(sock->ipc_pipe_name, NAMED_PIPE_PREFIX);
for (int i = strlen(sock->ipc_pipe_name); i < 31; i++) {
sock->ipc_pipe_name[i] = isc_random8() % 24 + 'a';
}
sock->ipc_pipe_name[31] = '\0';
snprintf(sock->ipc_pipe_name, sizeof(sock->ipc_pipe_name),
NAMED_PIPE_PATTERN, getpid(), isc_random32());
sock->ipc_pipe_name[sizeof(sock->ipc_pipe_name) - 1] = '\0';
isc_mutex_init(&sock->lock);
isc_condition_init(&sock->cond);

32
lib/isc/netmgr/tcp.c
View File

@@ -10,6 +10,7 @@
*/
#include <unistd.h>
#include <libgen.h>
#include <uv.h>
#include <isc/atomic.h>
@@ -203,6 +204,25 @@ isc_nm_listentcp(isc_nm_t *mgr, isc_nmiface_t *iface,
}
}
#ifndef WIN32
/*
* Run fsync() on the directory containing a socket's IPC pipe, to
* ensure that all threads can see the pipe.
*/
static void
syncdir(const isc_nmsocket_t *sock) {
char *pipe = isc_mem_strdup(sock->mgr->mctx, sock->ipc_pipe_name);
int fd = open(dirname(pipe), O_RDONLY);
RUNTIME_CHECK(fd >= 0);
isc_mem_free(sock->mgr->mctx, pipe);
fsync(fd);
close(fd);
}
#endif
/*
* For TCP listening, we create a single socket, bind it, and then
* pass it to `ncpu` child sockets - the passing is done over IPC.
@@ -274,7 +294,17 @@ isc__nm_async_tcplisten(isc__networker_t *worker, isc__netievent_t *ievent0) {
r = uv_listen((uv_stream_t *) &sock->ipc, sock->nchildren,
ipc_connection_cb);
INSIST(r == 0);
#ifndef WIN32
/*
* On Unices a child thread might not see the pipe yet;
* that happened quite often in unit tests on FreeBSD.
* Syncing the directory ensures that the pipe is visible
* to everyone.
* This isn't done on Windows because named pipes exist
* within a different namespace, not on VFS.
*/
syncdir(sock);
#endif
/*
* We launch n 'tcpchildlistener' that will receive
* sockets to be listened on over ipc.