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authorDenis Vlasenko2006-09-11 17:42:44 +0000
committerDenis Vlasenko2006-09-11 17:42:44 +0000
commit00d7d6cef6419654071ccc77d9b2f212198dab3d (patch)
treedd597506d203700ee8bdab93e5467cac0e2a1712 /util-linux
parent64d7e93081141cb6f1668436a5629a2304047f38 (diff)
downloadbusybox-00d7d6cef6419654071ccc77d9b2f212198dab3d.zip
busybox-00d7d6cef6419654071ccc77d9b2f212198dab3d.tar.gz
nfsmount: sanitize it. It had a rather peculiar idea of implementing "bg"
option - it was going to return a special flag back to caller and expecting caller to call it again with special parameter! Also caller was charged with calling mount() syscall... mount: mtab support was non-functional. Enabling it revealed serious bug which is not fixed yet.
Diffstat (limited to 'util-linux')
-rw-r--r--util-linux/mount.c28
-rw-r--r--util-linux/nfsmount.c380
2 files changed, 221 insertions, 187 deletions
diff --git a/util-linux/mount.c b/util-linux/mount.c
index b1d9e28..bd2a62d 100644
--- a/util-linux/mount.c
+++ b/util-linux/mount.c
@@ -102,7 +102,7 @@ static void append_mount_options(char **oldopts, char *newopts)
}
/* Use the mount_options list to parse options into flags.
- * Return list of unrecognized options in *strflags if strflags!=NULL */
+ * Also return list of unrecognized options if unrecognized!=NULL */
static int parse_mount_options(char *options, char **unrecognized)
{
int flags = MS_SILENT;
@@ -188,7 +188,7 @@ void delete_block_backed_filesystems(void);
#endif
#if ENABLE_FEATURE_MTAB_SUPPORT
-static int useMtab;
+static int useMtab = 1;
static int fakeIt;
#else
#define useMtab 0
@@ -196,8 +196,7 @@ static int fakeIt;
#endif
// Perform actual mount of specific filesystem at specific location.
-
-static int mount_it_now(struct mntent *mp, int vfsflags, char *filteropts)
+int mount_it_now(struct mntent *mp, int vfsflags, char *filteropts)
{
int rc;
@@ -228,7 +227,7 @@ static int mount_it_now(struct mntent *mp, int vfsflags, char *filteropts)
int i;
if(!mountTable)
- bb_error_msg("No %s",bb_path_mtab_file);
+ bb_error_msg("no %s",bb_path_mtab_file);
// Add vfs string flags
@@ -244,7 +243,13 @@ static int mount_it_now(struct mntent *mp, int vfsflags, char *filteropts)
// Write and close.
if(!mp->mnt_type || !*mp->mnt_type) mp->mnt_type="--bind";
- addmntent(mountTable, mp);
+// addmntent(mountTable, mp);
+if(0) bb_error_msg("buggy: addmntent(fsname='%s' dir='%s' type='%s' opts='%s')",
+mp->mnt_fsname,
+mp->mnt_dir,
+mp->mnt_type,
+mp->mnt_opts
+);
endmntent(mountTable);
if (ENABLE_FEATURE_CLEAN_UP)
if(strcmp(mp->mnt_type,"--bind")) mp->mnt_type = 0;
@@ -319,13 +324,7 @@ static int singlemount(struct mntent *mp, int ignore_busy)
(!mp->mnt_type || !strcmp(mp->mnt_type,"nfs")) &&
strchr(mp->mnt_fsname, ':') != NULL)
{
- if (nfsmount(mp->mnt_fsname, mp->mnt_dir, &vfsflags, &filteropts, 1)) {
- bb_perror_msg("nfsmount failed");
- } else {
- // Strangely enough, nfsmount() doesn't actually mount() anything.
- mp->mnt_type = "nfs";
- rc = mount_it_now(mp, vfsflags, filteropts);
- }
+ rc = nfsmount(mp, vfsflags, filteropts);
goto report_error;
}
@@ -400,7 +399,8 @@ report_error:
if (rc && errno == EBUSY && ignore_busy) rc = 0;
if (rc < 0)
- bb_perror_msg("mounting %s on %s failed", mp->mnt_fsname, mp->mnt_dir);
+ /* perror here sometimes says "mounting ... on ... failed: Success" */
+ bb_error_msg("mounting %s on %s failed", mp->mnt_fsname, mp->mnt_dir);
return rc;
}
diff --git a/util-linux/nfsmount.c b/util-linux/nfsmount.c
index d43bc3e..4e523b5 100644
--- a/util-linux/nfsmount.c
+++ b/util-linux/nfsmount.c
@@ -22,6 +22,8 @@
*/
#include "busybox.h"
+#include <syslog.h>
+#include <mntent.h>
#include <sys/utsname.h>
#undef TRUE
#undef FALSE
@@ -332,15 +334,8 @@ static bool_t xdr_mountres3(XDR *xdrs, mountres3 *objp)
return TRUE;
}
-
#define MAX_NFSPROT ((nfs_mount_version >= 4) ? 3 : 2)
-enum {
- EX_FAIL = 32, /* mount failure */
- EX_BG = 256 /* retry in background (internal only) */
-};
-
-
/*
* nfs_mount_version according to the sources seen at compile time.
*/
@@ -426,50 +421,62 @@ next:
return &p;
}
-int nfsmount(const char *spec, const char *node, int *flags,
- char **mount_opts, int running_bg)
+static int daemonize(void)
{
- /* prev_bg_host is a -o bg support:
- * "bg: if the first NFS mount attempt times out,
- * retry the mount in the background.
- * After a mount operation is backgrounded,
- * all subsequent mounts on the same NFS server
- * will be backgrounded immediately, without first
- * attempting the mount. A missing mount point is treated
- * as a timeout, to allow for nested NFS mounts."
- *
- * But current implementation is a dirty hack -
- * it works only if all mounts are to one host!
- * IOW: think what will happen if you have this sequence:
- * mount a.a.a.a:/dir /mnt/a -o bg
- * mount b.b.b.b:/dir /mnt/b -o bg
- * mount a.a.a.a:/dir /mnt/a -o bg
- * mount b.b.b.b:/dir /mnt/b -o bg
- */
+ int fd;
+ int pid = fork();
+ if (pid < 0) /* error */
+ return -errno;
+ if (pid > 0) /* parent */
+ return 0;
+ /* child */
+ fd = xopen(bb_dev_null, O_RDWR);
+ dup2(fd, 0);
+ dup2(fd, 1);
+ dup2(fd, 2);
+ if (fd > 2) close(fd);
+ setsid();
+ openlog(bb_applet_name, LOG_PID, LOG_DAEMON);
+ logmode = LOGMODE_SYSLOG;
+ return 1;
+}
+
+// TODO
+static inline int we_saw_this_host_before(const char *hostname)
+{
+ return 0;
+}
+
+/* RPC strerror analogs are terminally idiotic:
+ * *mandatory* prefix and \n at end.
+ * This hopefully helps. Usage:
+ * error_msg_rpc(clnt_*error*(" ")) */
+static void error_msg_rpc(const char *msg)
+{
+ size_t len;
+ while (msg[0] == ' ' || msg[0] == ':') msg++;
+ len = strlen(msg);
+ while (len && msg[len-1] == '\n') len--;
+ bb_error_msg("%.*s", len, msg);
+}
- static char *prev_bg_host;
- char *hostdir;
+int nfsmount(struct mntent *mp, int vfsflags, char *filteropts)
+{
CLIENT *mclient;
char *hostname;
char *pathname;
- char *old_opts;
char *mounthost;
- struct timeval total_timeout;
- enum clnt_stat clnt_stat;
struct nfs_mount_data data;
- char *opt, *opteq;
- int val;
+ char *opt;
struct hostent *hp;
struct sockaddr_in server_addr;
struct sockaddr_in mount_server_addr;
- struct pmap* pm_mnt;
int msock, fsock;
- struct timeval retry_timeout;
union {
struct fhstatus nfsv2;
struct mountres3 nfsv3;
} status;
- struct stat statbuf;
+ int daemonized;
char *s;
int port;
int mountport;
@@ -488,29 +495,27 @@ int nfsmount(const char *spec, const char *node, int *flags,
int nfsprog;
int nfsvers;
int retval;
- time_t t;
- time_t prevt;
- time_t timeout;
find_kernel_nfs_mount_version();
- /* NB: old_opts and hostdir must be free()d prior to return! */
-
- old_opts = NULL;
+ daemonized = 0;
mounthost = NULL;
- retval = EX_FAIL;
+ retval = ETIMEDOUT;
msock = fsock = -1;
mclient = NULL;
- hostdir = xstrdup(spec);
+ /* NB: hostname, mounthost, filteropts must be free()d prior to return */
+
+ filteropts = xstrdup(filteropts); /* going to trash it later... */
+
+ hostname = xstrdup(mp->mnt_fsname);
/* mount_main() guarantees that ':' is there */
- s = strchr(hostdir, ':');
- hostname = hostdir;
+ s = strchr(hostname, ':');
pathname = s + 1;
*s = '\0';
/* Ignore all but first hostname in replicated mounts
until they can be fully supported. (mack@sgi.com) */
- s = strchr(hostdir, ',');
+ s = strchr(hostname, ',');
if (s) {
*s = '\0';
bb_error_msg("warning: multiple hostnames not supported");
@@ -538,12 +543,15 @@ int nfsmount(const char *spec, const char *node, int *flags,
/* add IP address to mtab options for use when unmounting */
- s = inet_ntoa(server_addr.sin_addr);
- old_opts = *mount_opts;
- if (!old_opts)
- old_opts = xstrdup("");
- *mount_opts = xasprintf("%s%saddr=%s",
- old_opts, *old_opts ? "," : "", s);
+ if (!mp->mnt_opts) { /* TODO: actually mp->mnt_opts is never NULL */
+ mp->mnt_opts = xasprintf("addr=%s", inet_ntoa(server_addr.sin_addr));
+ } else {
+ char *tmp = xasprintf("%s%saddr=%s", mp->mnt_opts,
+ mp->mnt_opts[0] ? "," : "",
+ inet_ntoa(server_addr.sin_addr));
+ free(mp->mnt_opts);
+ mp->mnt_opts = tmp;
+ }
/* Set default options.
* rsize/wsize (and bsize, for ver >= 3) are left 0 in order to
@@ -576,10 +584,10 @@ int nfsmount(const char *spec, const char *node, int *flags,
/* parse options */
- for (opt = strtok(old_opts, ","); opt; opt = strtok(NULL, ",")) {
- opteq = strchr(opt, '=');
+ for (opt = strtok(filteropts, ","); opt; opt = strtok(NULL, ",")) {
+ char *opteq = strchr(opt, '=');
if (opteq) {
- val = atoi(opteq + 1);
+ int val = atoi(opteq + 1);
*opteq = '\0';
if (!strcmp(opt, "rsize"))
data.rsize = val;
@@ -641,7 +649,7 @@ int nfsmount(const char *spec, const char *node, int *flags,
}
}
else {
- val = 1;
+ int val = 1;
if (!strncmp(opt, "no", 2)) {
val = 0;
opt += 2;
@@ -723,19 +731,20 @@ int nfsmount(const char *spec, const char *node, int *flags,
data.version = nfs_mount_version;
- if (*flags & MS_REMOUNT)
- goto copy_data_and_return;
+ if (vfsflags & MS_REMOUNT)
+ goto do_mount;
/*
* If the previous mount operation on the same host was
* backgrounded, and the "bg" for this mount is also set,
* give up immediately, to avoid the initial timeout.
*/
- if (bg && !running_bg &&
- prev_bg_host && strcmp(hostname, prev_bg_host) == 0) {
- if (retry > 0)
- retval = EX_BG;
- goto ret;
+ if (bg && we_saw_this_host_before(hostname)) {
+ daemonized = daemonize(); /* parent or error */
+ if (daemonized <= 0) { /* parent or error */
+ retval = -daemonized;
+ goto ret;
+ }
}
/* create mount daemon client */
@@ -745,7 +754,8 @@ int nfsmount(const char *spec, const char *node, int *flags,
mount_server_addr.sin_family = AF_INET;
mount_server_addr.sin_addr.s_addr = inet_addr(hostname);
} else {
- if ((hp = gethostbyname(mounthost)) == NULL) {
+ hp = gethostbyname(mounthost);
+ if (hp == NULL) {
bb_herror_msg("%s", mounthost);
goto fail;
} else {
@@ -761,11 +771,9 @@ int nfsmount(const char *spec, const char *node, int *flags,
}
/*
- * The following loop implements the mount retries. On the first
- * call, "running_bg" is 0. When the mount times out, and the
- * "bg" option is set, the exit status EX_BG will be returned.
- * For a backgrounded mount, there will be a second call by the
- * child process with "running_bg" set to 1.
+ * The following loop implements the mount retries. When the mount
+ * times out, and the "bg" option is set, we background ourself
+ * and continue trying.
*
* The case where the mount point is not present and the "bg"
* option is set, is treated as a timeout. This is done to
@@ -773,115 +781,122 @@ int nfsmount(const char *spec, const char *node, int *flags,
*
* The "retry" count specified by the user is the number of
* minutes to retry before giving up.
- *
- * Only the first error message will be displayed.
*/
- retry_timeout.tv_sec = 3;
- retry_timeout.tv_usec = 0;
- total_timeout.tv_sec = 20;
- total_timeout.tv_usec = 0;
- timeout = time(NULL) + 60 * retry;
- prevt = 0;
- t = 30;
- val = 1;
- for (;;) {
- if (bg && stat(node, &statbuf) == -1) {
- if (running_bg) {
- sleep(val); /* 1, 2, 4, 8, 16, 30, ... */
- val *= 2;
- if (val > 30)
- val = 30;
- }
- } else {
- /* be careful not to use too many CPU cycles */
- if (t - prevt < 30)
- sleep(30);
-
- pm_mnt = get_mountport(&mount_server_addr,
- mountprog,
- mountvers,
- proto,
- mountport);
-
- /* contact the mount daemon via TCP */
- mount_server_addr.sin_port = htons(pm_mnt->pm_port);
- msock = RPC_ANYSOCK;
-
- switch (pm_mnt->pm_prot) {
- case IPPROTO_UDP:
- mclient = clntudp_create(&mount_server_addr,
+ {
+ struct timeval total_timeout;
+ struct timeval retry_timeout;
+ struct pmap* pm_mnt;
+ time_t t;
+ time_t prevt;
+ time_t timeout;
+
+ retry_timeout.tv_sec = 3;
+ retry_timeout.tv_usec = 0;
+ total_timeout.tv_sec = 20;
+ total_timeout.tv_usec = 0;
+ timeout = time(NULL) + 60 * retry;
+ prevt = 0;
+ t = 30;
+retry:
+ /* be careful not to use too many CPU cycles */
+ if (t - prevt < 30)
+ sleep(30);
+
+ pm_mnt = get_mountport(&mount_server_addr,
+ mountprog,
+ mountvers,
+ proto,
+ mountport);
+ nfsvers = (pm_mnt->pm_vers < 2) ? 2 : pm_mnt->pm_vers;
+
+ /* contact the mount daemon via TCP */
+ mount_server_addr.sin_port = htons(pm_mnt->pm_port);
+ msock = RPC_ANYSOCK;
+
+ switch (pm_mnt->pm_prot) {
+ case IPPROTO_UDP:
+ mclient = clntudp_create(&mount_server_addr,
pm_mnt->pm_prog,
pm_mnt->pm_vers,
retry_timeout,
&msock);
- if (mclient)
- break;
- mount_server_addr.sin_port = htons(pm_mnt->pm_port);
- msock = RPC_ANYSOCK;
- case IPPROTO_TCP:
- mclient = clnttcp_create(&mount_server_addr,
+ if (mclient)
+ break;
+ mount_server_addr.sin_port = htons(pm_mnt->pm_port);
+ msock = RPC_ANYSOCK;
+ case IPPROTO_TCP:
+ mclient = clnttcp_create(&mount_server_addr,
pm_mnt->pm_prog,
pm_mnt->pm_vers,
&msock, 0, 0);
- break;
- default:
- mclient = 0;
- }
- if (mclient) {
- /* try to mount hostname:pathname */
- mclient->cl_auth = authunix_create_default();
-
- /* make pointers in xdr_mountres3 NULL so
- * that xdr_array allocates memory for us
- */
- memset(&status, 0, sizeof(status));
-
- if (pm_mnt->pm_vers == 3)
- clnt_stat = clnt_call(mclient, MOUNTPROC3_MNT,
- (xdrproc_t) xdr_dirpath,
- (caddr_t) &pathname,
- (xdrproc_t) xdr_mountres3,
- (caddr_t) &status,
- total_timeout);
- else
- clnt_stat = clnt_call(mclient, MOUNTPROC_MNT,
- (xdrproc_t) xdr_dirpath,
- (caddr_t) &pathname,
- (xdrproc_t) xdr_fhstatus,
- (caddr_t) &status,
- total_timeout);
-
- if (clnt_stat == RPC_SUCCESS)
- break; /* we're done */
- if (errno != ECONNREFUSED) {
- clnt_perror(mclient, "mount");
- goto fail; /* don't retry */
- }
- if (!running_bg && prevt == 0)
- clnt_perror(mclient, "mount");
- auth_destroy(mclient->cl_auth);
- clnt_destroy(mclient);
- mclient = 0;
- close(msock);
- } else {
- if (!running_bg && prevt == 0)
- clnt_pcreateerror("mount");
+ break;
+ default:
+ mclient = 0;
+ }
+ if (!mclient) {
+ if (!daemonized && prevt == 0)
+ error_msg_rpc(clnt_spcreateerror(" "));
+ } else {
+ enum clnt_stat clnt_stat;
+ /* try to mount hostname:pathname */
+ mclient->cl_auth = authunix_create_default();
+
+ /* make pointers in xdr_mountres3 NULL so
+ * that xdr_array allocates memory for us
+ */
+ memset(&status, 0, sizeof(status));
+
+ if (pm_mnt->pm_vers == 3)
+ clnt_stat = clnt_call(mclient, MOUNTPROC3_MNT,
+ (xdrproc_t) xdr_dirpath,
+ (caddr_t) &pathname,
+ (xdrproc_t) xdr_mountres3,
+ (caddr_t) &status,
+ total_timeout);
+ else
+ clnt_stat = clnt_call(mclient, MOUNTPROC_MNT,
+ (xdrproc_t) xdr_dirpath,
+ (caddr_t) &pathname,
+ (xdrproc_t) xdr_fhstatus,
+ (caddr_t) &status,
+ total_timeout);
+
+ if (clnt_stat == RPC_SUCCESS)
+ goto prepare_kernel_data; /* we're done */
+ if (errno != ECONNREFUSED) {
+ error_msg_rpc(clnt_sperror(mclient, " "));
+ goto fail; /* don't retry */
}
- prevt = t;
+ /* Connection refused */
+ if (!daemonized && prevt == 0) /* print just once */
+ error_msg_rpc(clnt_sperror(mclient, " "));
+ auth_destroy(mclient->cl_auth);
+ clnt_destroy(mclient);
+ mclient = 0;
+ close(msock);
}
+
+ /* Timeout. We are going to retry... maybe */
+
if (!bg)
goto fail;
- if (!running_bg) {
- prev_bg_host = xstrdup(hostname);
- if (retry > 0)
- retval = EX_BG;
- goto fail;
+ if (!daemonized) {
+ daemonized = daemonize();
+ if (daemonized <= 0) { /* parent or error */
+ retval = -daemonized;
+ goto ret;
+ }
}
+ prevt = t;
t = time(NULL);
if (t >= timeout)
+ /* TODO error message */
goto fail;
+
+ goto retry;
}
- nfsvers = (pm_mnt->pm_vers < 2) ? 2 : pm_mnt->pm_vers;
+
+prepare_kernel_data:
if (nfsvers == 2) {
if (status.nfsv2.fhs_status != 0) {
@@ -927,17 +942,17 @@ int nfsmount(const char *spec, const char *node, int *flags,
} else
fsock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
if (fsock < 0) {
- perror("nfs socket");
+ bb_perror_msg("nfs socket");
goto fail;
}
if (bindresvport(fsock, 0) < 0) {
- perror("nfs bindresvport");
+ bb_perror_msg("nfs bindresvport");
goto fail;
}
if (port == 0) {
server_addr.sin_port = PMAPPORT;
port = pmap_getport(&server_addr, nfsprog, nfsvers,
- tcp ? IPPROTO_TCP : IPPROTO_UDP);
+ tcp ? IPPROTO_TCP : IPPROTO_UDP);
if (port == 0)
port = NFS_PORT;
#ifdef NFS_MOUNT_DEBUG
@@ -961,16 +976,34 @@ int nfsmount(const char *spec, const char *node, int *flags,
auth_destroy(mclient->cl_auth);
clnt_destroy(mclient);
close(msock);
-copy_data_and_return:
- *mount_opts = xrealloc(*mount_opts, sizeof(data));
- memcpy(*mount_opts, &data, sizeof(data));
- retval = 0;
+ if (bg) {
+ /* We must wait until mount directory is available */
+ struct stat statbuf;
+ int delay = 1;
+ while (stat(mp->mnt_dir, &statbuf) == -1) {
+ if (!daemonized) {
+ daemonized = daemonize();
+ if (daemonized <= 0) { /* parent or error */
+ retval = -daemonized;
+ goto ret;
+ }
+ }
+ sleep(delay); /* 1, 2, 4, 8, 16, 30, ... */
+ delay *= 2;
+ if (delay > 30)
+ delay = 30;
+ }
+ }
+
+do_mount: /* perform actual mount */
+
+ mp->mnt_type = "nfs";
+ retval = mount_it_now(mp, vfsflags, (char*)&data);
goto ret;
- /* abort */
+fail: /* abort */
-fail:
if (msock != -1) {
if (mclient) {
auth_destroy(mclient->cl_auth);
@@ -982,7 +1015,8 @@ fail:
close(fsock);
ret:
- free(hostdir);
- free(old_opts);
+ free(hostname);
+ free(mounthost);
+ free(filteropts);
return retval;
}