Clean up the svr4 socket cache and streams code some to make it more easily
locked. - Move all the svr4 socket cache code into svr4_socket.c, specifically move svr4_delete_socket() over from streams.c. Make the socket cache entry structure and svr4_head private to svr4_socket.c as a result. - Add a mutex to protect the svr4 socket cache. - Change svr4_find_socket() to copy the sockaddr_un struct into a caller-supplied sockaddr_un rather than giving the caller a pointer to our internal one. This removes the one case where code outside of svr4_socket.c could access data in the cache. - Add an eventhandler for process_exit and process_exec to purge the cache of any entries for the exiting or execing process. - Add methods to init and destroy the socket cache and call them from the svr4 ABI module's event handler. - Conditionally grab Giant around socreate() in streamsopen(). - Use fdclose() instead of inlining it in streamsopen() when handling socreate() failure. - Only allocate a stream structure and attach it to a socket in streamsopen(). Previously, if a svr4 program performed a stream operation on an arbitrary socket not opened via the streams device, we would attach streams state data to it and change f_ops of the associated struct file while it was in use. The latter was especially not safe, and if a program wants a stream object it should open it via the streams device anyway. - Don't bother locking so_emuldata in the streams code now that we only touch it right after creating a socket (in streamsopen()) or when tearing it down when the file is closed. - Remove D_NEEDGIANT from the streams device as it is no longer needed.
This commit is contained in:
John Baldwin
parent
52d639a953
commit
e0569c0798
@ -46,7 +46,9 @@ __FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/queue.h>
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#include <sys/eventhandler.h>
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#include <sys/file.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/mutex.h>
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#include <sys/socket.h>
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@ -65,17 +67,34 @@ __FBSDID("$FreeBSD$");
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#include <compat/svr4/svr4_sockmod.h>
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#include <compat/svr4/svr4_proto.h>
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struct sockaddr_un *
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svr4_find_socket(td, fp, dev, ino)
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struct svr4_sockcache_entry {
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struct proc *p; /* Process for the socket */
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void *cookie; /* Internal cookie used for matching */
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struct sockaddr_un sock;/* Pathname for the socket */
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dev_t dev; /* Device where the socket lives on */
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ino_t ino; /* Inode where the socket lives on */
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TAILQ_ENTRY(svr4_sockcache_entry) entries;
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};
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static TAILQ_HEAD(, svr4_sockcache_entry) svr4_head;
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static struct mtx svr4_sockcache_lock;
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static eventhandler_tag svr4_sockcache_exit_tag, svr4_sockcache_exec_tag;
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static void svr4_purge_sockcache(void *arg, struct proc *p);
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int
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svr4_find_socket(td, fp, dev, ino, saun)
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struct thread *td;
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struct file *fp;
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dev_t dev;
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ino_t ino;
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struct sockaddr_un *saun;
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{
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struct svr4_sockcache_entry *e;
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void *cookie = ((struct socket *)fp->f_data)->so_emuldata;
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DPRINTF(("svr4_find_socket: [%p,%d,%d]: ", td, dev, ino));
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mtx_lock(&svr4_sockcache_lock);
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TAILQ_FOREACH(e, &svr4_head, entries)
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if (e->p == td->td_proc && e->dev == dev && e->ino == ino) {
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#ifdef DIAGNOSTIC
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@ -84,18 +103,16 @@ svr4_find_socket(td, fp, dev, ino)
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#endif
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e->cookie = cookie;
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DPRINTF(("%s\n", e->sock.sun_path));
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return &e->sock;
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*saun = e->sock;
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mtx_unlock(&svr4_sockcache_lock);
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return (0);
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}
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mtx_unlock(&svr4_sockcache_lock);
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DPRINTF(("not found\n"));
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return NULL;
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return (ENOENT);
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}
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/*
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* svr4_delete_socket() is in sys/dev/streams.c (because it's called by
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* the streams "soo_close()" routine).
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*/
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int
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svr4_add_socket(td, path, st)
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struct thread *td;
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@ -105,8 +122,6 @@ svr4_add_socket(td, path, st)
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struct svr4_sockcache_entry *e;
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int len, error;
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mtx_lock(&Giant);
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e = malloc(sizeof(*e), M_TEMP, M_WAITOK);
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e->cookie = NULL;
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e->dev = st->st_dev;
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@ -115,7 +130,6 @@ svr4_add_socket(td, path, st)
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if ((error = copyinstr(path, e->sock.sun_path,
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sizeof(e->sock.sun_path), &len)) != 0) {
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mtx_unlock(&Giant);
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DPRINTF(("svr4_add_socket: copyinstr failed %d\n", error));
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free(e, M_TEMP);
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return error;
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@ -124,13 +138,76 @@ svr4_add_socket(td, path, st)
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e->sock.sun_family = AF_LOCAL;
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e->sock.sun_len = len;
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mtx_lock(&svr4_sockcache_lock);
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TAILQ_INSERT_HEAD(&svr4_head, e, entries);
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mtx_unlock(&Giant);
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mtx_unlock(&svr4_sockcache_lock);
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DPRINTF(("svr4_add_socket: %s [%p,%d,%d]\n", e->sock.sun_path,
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td->td_proc, e->dev, e->ino));
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return 0;
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}
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void
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svr4_delete_socket(p, fp)
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struct proc *p;
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struct file *fp;
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{
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struct svr4_sockcache_entry *e;
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void *cookie = ((struct socket *)fp->f_data)->so_emuldata;
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mtx_lock(&svr4_sockcache_lock);
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TAILQ_FOREACH(e, &svr4_head, entries)
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if (e->p == p && e->cookie == cookie) {
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TAILQ_REMOVE(&svr4_head, e, entries);
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mtx_unlock(&svr4_sockcache_lock);
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DPRINTF(("svr4_delete_socket: %s [%p,%d,%d]\n",
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e->sock.sun_path, p, (int)e->dev, e->ino));
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free(e, M_TEMP);
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return;
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}
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mtx_unlock(&svr4_sockcache_lock);
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}
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void
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svr4_purge_sockcache(arg, p)
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void *arg;
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struct proc *p;
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{
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struct svr4_sockcache_entry *e, *ne;
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mtx_lock(&svr4_sockcache_lock);
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TAILQ_FOREACH_SAFE(e, &svr4_head, entries, ne) {
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if (e->p == p) {
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TAILQ_REMOVE(&svr4_head, e, entries);
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DPRINTF(("svr4_purge_sockcache: %s [%p,%d,%d]\n",
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e->sock.sun_path, p, (int)e->dev, e->ino));
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free(e, M_TEMP);
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}
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}
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mtx_unlock(&svr4_sockcache_lock);
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}
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void
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svr4_sockcache_init(void)
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{
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TAILQ_INIT(&svr4_head);
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mtx_init(&svr4_sockcache_lock, "svr4 socket cache", NULL, MTX_DEF);
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svr4_sockcache_exit_tag = EVENTHANDLER_REGISTER(process_exit,
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svr4_purge_sockcache, NULL, EVENTHANDLER_PRI_ANY);
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svr4_sockcache_exec_tag = EVENTHANDLER_REGISTER(process_exec,
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svr4_purge_sockcache, NULL, EVENTHANDLER_PRI_ANY);
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}
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void
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svr4_sockcache_destroy(void)
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{
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KASSERT(TAILQ_EMPTY(&svr4_head),
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("%s: sockcache entries still around", __func__));
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EVENTHANDLER_DEREGISTER(process_exec, svr4_sockcache_exec_tag);
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EVENTHANDLER_DEREGISTER(process_exit, svr4_sockcache_exit_tag);
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mtx_destroy(&svr4_sockcache_lock);
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}
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int
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svr4_sys_socket(td, uap)
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@ -48,22 +48,11 @@ struct svr4_sockaddr_in {
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u_char sin_zero[8];
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};
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struct sockaddr_un *svr4_find_socket(struct thread *, struct file *,
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dev_t, ino_t);
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void svr4_delete_socket(struct proc *, struct file *);
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int svr4_add_socket(struct thread *, const char *, struct stat *);
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struct svr4_sockcache_entry {
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struct proc *p; /* Process for the socket */
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void *cookie; /* Internal cookie used for matching */
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struct sockaddr_un sock;/* Pathname for the socket */
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dev_t dev; /* Device where the socket lives on */
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ino_t ino; /* Inode where the socket lives on */
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TAILQ_ENTRY(svr4_sockcache_entry) entries;
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};
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TAILQ_HEAD(svr4_sockcache_head, svr4_sockcache_entry);
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extern struct svr4_sockcache_head svr4_head;
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extern int svr4_str_initialized;
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int svr4_add_socket(struct thread *, const char *, struct stat *);
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void svr4_delete_socket(struct proc *, struct file *);
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int svr4_find_socket(struct thread *, struct file *, dev_t, ino_t,
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struct sockaddr_un *);
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void svr4_sockcache_init(void);
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void svr4_sockcache_destroy(void);
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#endif /* _SVR4_SOCKET_H_ */
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@ -1554,13 +1554,11 @@ svr4_do_putmsg(td, uap, fp)
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/* Maybe we've been given a device/inode pair */
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dev_t *dev = SVR4_ADDROF(&sc);
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ino_t *ino = (ino_t *) &dev[1];
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sa = (struct sockaddr *)
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svr4_find_socket(td, fp, *dev, *ino);
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if (sa == NULL) {
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sa = (struct sockaddr *)&saun;
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if (svr4_find_socket(td, fp, *dev, *ino, &saun) != 0) {
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/* I guess we have it by name */
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netaddr_to_sockaddr_un(&saun, &sc);
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}
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sa = (struct sockaddr *)&saun;
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sasize = sizeof(saun);
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}
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break;
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@ -62,6 +62,7 @@ __FBSDID("$FreeBSD$");
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#include <compat/svr4/svr4_types.h>
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#include <compat/svr4/svr4_syscall.h>
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#include <compat/svr4/svr4_signal.h>
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#include <compat/svr4/svr4_socket.h>
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#include <compat/svr4/svr4_sockio.h>
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#include <compat/svr4/svr4_errno.h>
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#include <compat/svr4/svr4_proto.h>
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@ -269,12 +270,14 @@ svr4_elf_modevent(module_t mod, int type, void *data)
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switch(type) {
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case MOD_LOAD:
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if (elf32_insert_brand_entry(&svr4_brand) < 0)
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error = EINVAL;
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if (error)
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if (elf32_insert_brand_entry(&svr4_brand) < 0) {
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printf("cannot insert svr4 elf brand handler\n");
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else if (bootverbose)
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error = EINVAL;
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break;
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}
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if (bootverbose)
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printf("svr4 ELF exec handler installed\n");
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svr4_sockcache_init();
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break;
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case MOD_UNLOAD:
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/* Only allow the emulator to be removed if it isn't in use. */
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@ -284,11 +287,14 @@ svr4_elf_modevent(module_t mod, int type, void *data)
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error = EINVAL;
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}
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if (error)
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if (error) {
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printf("Could not deinstall ELF interpreter entry (error %d)\n",
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error);
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else if (bootverbose)
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break;
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}
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if (bootverbose)
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printf("svr4 ELF exec handler removed\n");
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svr4_sockcache_destroy();
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break;
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default:
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return (EOPNOTSUPP);
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@ -68,8 +68,6 @@ static int svr4_soo_close(struct file *, struct thread *);
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static int svr4_ptm_alloc(struct thread *);
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static d_open_t streamsopen;
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struct svr4_sockcache_head svr4_head;
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/*
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* Device minor numbers
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*/
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@ -101,7 +99,6 @@ static struct fileops svr4_netops = {
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static struct cdevsw streams_cdevsw = {
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.d_version = D_VERSION,
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.d_flags = D_NEEDGIANT,
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.d_open = streamsopen,
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.d_name = "streams",
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};
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@ -119,7 +116,6 @@ streams_modevent(module_t mod, int type, void *unused)
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{
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switch (type) {
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case MOD_LOAD:
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TAILQ_INIT(&svr4_head);
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dt_ptm = make_dev(&streams_cdevsw, dev_ptm, 0, 0, 0666,
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"ptm");
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dt_arp = make_dev(&streams_cdevsw, dev_arp, 0, 0, 0666,
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@ -187,13 +183,12 @@ MODULE_VERSION(streams, 1);
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static int
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streamsopen(struct cdev *dev, int oflags, int devtype, struct thread *td)
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{
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int type, protocol;
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int fd, extraref;
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struct file *fp;
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struct filedesc *fdp;
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struct svr4_strm *st;
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struct socket *so;
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int error;
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int family;
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struct proc *p = td->td_proc;
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struct file *fp;
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int family, type, protocol;
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int error, fd;
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if (td->td_dupfd >= 0)
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return ENODEV;
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@ -244,34 +239,40 @@ streamsopen(struct cdev *dev, int oflags, int devtype, struct thread *td)
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return EOPNOTSUPP;
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}
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fdp = td->td_proc->p_fd;
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if ((error = falloc(td, &fp, &fd)) != 0)
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return error;
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/* An extra reference on `fp' has been held for us by falloc(). */
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if ((error = socreate(family, &so, type, protocol,
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td->td_ucred, td)) != 0) {
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FILEDESC_LOCK_FAST(p->p_fd);
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/* Check the fd table entry hasn't changed since we made it. */
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extraref = 0;
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if (p->p_fd->fd_ofiles[fd] == fp) {
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p->p_fd->fd_ofiles[fd] = NULL;
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extraref = 1;
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}
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FILEDESC_UNLOCK_FAST(p->p_fd);
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if (extraref)
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fdrop(fp, td);
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fdrop(fp, td);
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return error;
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NET_LOCK_GIANT();
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error = socreate(family, &so, type, protocol, td->td_ucred, td);
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NET_UNLOCK_GIANT();
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if (error) {
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fdclose(fdp, fp, fd, td);
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fdrop(fp, td);
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return error;
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}
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FILEDESC_LOCK_FAST(p->p_fd);
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FILEDESC_LOCK_FAST(fdp);
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fp->f_data = so;
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fp->f_flag = FREAD|FWRITE;
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fp->f_ops = &svr4_netops;
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fp->f_type = DTYPE_SOCKET;
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FILEDESC_UNLOCK_FAST(p->p_fd);
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FILEDESC_UNLOCK_FAST(fdp);
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/*
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* Allocate a stream structure and attach it to this socket.
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* We don't bother locking so_emuldata for SVR4 stream sockets as
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* its value is constant for the lifetime of the stream once it
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* is initialized here.
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*/
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st = malloc(sizeof(struct svr4_strm), M_TEMP, M_WAITOK);
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st->s_family = so->so_proto->pr_domain->dom_family;
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st->s_cmd = ~0;
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st->s_afd = -1;
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st->s_eventmask = 0;
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so->so_emuldata = st;
|
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(void)svr4_stream_get(fp);
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fdrop(fp, td);
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td->td_dupfd = fd;
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return ENXIO;
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@ -334,59 +335,12 @@ svr4_stream_get(fp)
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struct file *fp;
|
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{
|
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struct socket *so;
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struct svr4_strm *st;
|
||||
|
||||
if (fp == NULL || fp->f_type != DTYPE_SOCKET)
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return NULL;
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|
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so = fp->f_data;
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|
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/*
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||||
* mpfixme: lock socketbuffer here
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||||
*/
|
||||
if (so->so_emuldata) {
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return so->so_emuldata;
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||||
}
|
||||
|
||||
/* Allocate a new one. */
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st = malloc(sizeof(struct svr4_strm), M_TEMP, M_WAITOK);
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st->s_family = so->so_proto->pr_domain->dom_family;
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st->s_cmd = ~0;
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st->s_afd = -1;
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st->s_eventmask = 0;
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||||
/*
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||||
* avoid a race where we loose due to concurrancy issues
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* of two threads trying to allocate the so_emuldata.
|
||||
*/
|
||||
if (so->so_emuldata) {
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/* lost the race, use the existing emuldata */
|
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FREE(st, M_TEMP);
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st = so->so_emuldata;
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||||
} else {
|
||||
/* we won, or there was no race, use our copy */
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so->so_emuldata = st;
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fp->f_ops = &svr4_netops;
|
||||
}
|
||||
|
||||
return st;
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||||
}
|
||||
|
||||
void
|
||||
svr4_delete_socket(p, fp)
|
||||
struct proc *p;
|
||||
struct file *fp;
|
||||
{
|
||||
struct svr4_sockcache_entry *e;
|
||||
void *cookie = ((struct socket *)fp->f_data)->so_emuldata;
|
||||
|
||||
TAILQ_FOREACH(e, &svr4_head, entries)
|
||||
if (e->p == p && e->cookie == cookie) {
|
||||
TAILQ_REMOVE(&svr4_head, e, entries);
|
||||
DPRINTF(("svr4_delete_socket: %s [%p,%d,%d]\n",
|
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e->sock.sun_path, p, (int)e->dev, e->ino));
|
||||
free(e, M_TEMP);
|
||||
return;
|
||||
}
|
||||
return so->so_emuldata;
|
||||
}
|
||||
|
||||
static int
|
||||
|
||||
Loading…
Reference in New Issue
Block a user