X-Git-Url: https://git.decadent.org.uk/gitweb/?p=nfs-utils.git;a=blobdiff_plain;f=utils%2Fmountd%2Fcache.c;h=0af640441b9b86eab0f0dd023f8ed985b4b4d410;hp=68cccdfddb70535f58c248798839fff5338ba656;hb=12a31b8011ab258fc726300dcfbb7a03af74adb3;hpb=40aed2c3fb5164195a9975ae7f15ebd4b992839d

diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c
index 68cccdf..0af6404 100644
--- a/utils/mountd/cache.c
+++ b/utils/mountd/cache.c
@@ -341,63 +341,49 @@ static char *next_mnt(void **v, char *p)
 	return me->mnt_dir;
 }
 
-static void nfsd_fh(FILE *f)
+/* True iff e1 is a child of e2 and e2 has crossmnt set: */
+static bool subexport(struct exportent *e1, struct exportent *e2)
 {
-	/* request are:
-	 *  domain fsidtype fsid
-	 * interpret fsid, find export point and options, and write:
-	 *  domain fsidtype fsid expiry path
-	 */
-	char *cp;
-	char *dom;
-	int fsidtype;
-	int fsidlen;
-	unsigned int dev, major=0, minor=0;
-	unsigned int inode=0;
-	unsigned long long inode64;
-	unsigned int fsidnum=0;
-	char fsid[32];
-	struct exportent *found = NULL;
-	struct addrinfo *ai = NULL;
-	char *found_path = NULL;
-	nfs_export *exp;
-	int i;
-	int dev_missing = 0;
-	int uuidlen = 0;
-	char *fhuuid = NULL;
+	char *p1 = e1->e_path, *p2 = e2->e_path;
+	int l2 = strlen(p2);
 
-	if (readline(fileno(f), &lbuf, &lbuflen) != 1)
-		return;
+	return e2->e_flags & NFSEXP_CROSSMOUNT
+	       && strncmp(p1, p2, l2) == 0
+	       && p1[l2] == '/';
+}
 
-	xlog(D_CALL, "nfsd_fh: inbuf '%s'", lbuf);
+struct parsed_fsid {
+	int fsidtype;
+	/* We could use a union for this, but it would be more
+	 * complicated; why bother? */
+	unsigned int inode;
+	unsigned int minor;
+	unsigned int major;
+	unsigned int fsidnum;
+	int uuidlen;
+	char *fhuuid;
+};
 
-	cp = lbuf;
-	
-	dom = malloc(strlen(cp));
-	if (dom == NULL)
-		return;
-	if (qword_get(&cp, dom, strlen(cp)) <= 0)
-		goto out;
-	if (qword_get_int(&cp, &fsidtype) != 0)
-		goto out;
-	if (fsidtype < 0 || fsidtype > 7)
-		goto out; /* unknown type */
-	if ((fsidlen = qword_get(&cp, fsid, 32)) <= 0)
-		goto out;
+int parse_fsid(int fsidtype, int fsidlen, char *fsid, struct parsed_fsid *parsed)
+{
+	unsigned int dev;
+	unsigned long long inode64;
+
+	parsed->fsidtype = fsidtype;
 	switch(fsidtype) {
 	case FSID_DEV: /* 4 bytes: 2 major, 2 minor, 4 inode */
 		if (fsidlen != 8)
-			goto out;
+			return -1;
 		memcpy(&dev, fsid, 4);
-		memcpy(&inode, fsid+4, 4);
-		major = ntohl(dev)>>16;
-		minor = ntohl(dev) & 0xFFFF;
+		memcpy(&parsed->inode, fsid+4, 4);
+		parsed->major = ntohl(dev)>>16;
+		parsed->minor = ntohl(dev) & 0xFFFF;
 		break;
 
 	case FSID_NUM: /* 4 bytes - fsid */
 		if (fsidlen != 4)
-			goto out;
-		memcpy(&fsidnum, fsid, 4);
+			return -1;
+		memcpy(&parsed->fsidnum, fsid, 4);
 		break;
 
 	case FSID_MAJOR_MINOR: /* 12 bytes: 4 major, 4 minor, 4 inode 
@@ -405,10 +391,12 @@ static void nfsd_fh(FILE *f)
 		 * an historical accident
 		 */
 		if (fsidlen != 12)
-			goto out;
-		memcpy(&dev, fsid, 4); major = ntohl(dev);
-		memcpy(&dev, fsid+4, 4); minor = ntohl(dev);
-		memcpy(&inode, fsid+8, 4);
+			return -1;
+		memcpy(&dev, fsid, 4);
+		parsed->major = ntohl(dev);
+		memcpy(&dev, fsid+4, 4);
+		parsed->minor = ntohl(dev);
+		memcpy(&parsed->inode, fsid+8, 4);
 		break;
 
 	case FSID_ENCODE_DEV: /* 8 bytes: 4 byte packed device number, 4 inode */
@@ -416,41 +404,137 @@ static void nfsd_fh(FILE *f)
 		 * no-one outside this host has any business interpreting it
 		 */
 		if (fsidlen != 8)
-			goto out;
+			return -1;
 		memcpy(&dev, fsid, 4);
-		memcpy(&inode, fsid+4, 4);
-		major = (dev & 0xfff00) >> 8;
-		minor = (dev & 0xff) | ((dev >> 12) & 0xfff00);
+		memcpy(&parsed->inode, fsid+4, 4);
+		parsed->major = (dev & 0xfff00) >> 8;
+		parsed->minor = (dev & 0xff) | ((dev >> 12) & 0xfff00);
 		break;
 
 	case FSID_UUID4_INUM: /* 4 byte inode number and 4 byte uuid */
 		if (fsidlen != 8)
-			goto out;
-		memcpy(&inode, fsid, 4);
-		uuidlen = 4;
-		fhuuid = fsid+4;
+			return -1;
+		memcpy(&parsed->inode, fsid, 4);
+		parsed->uuidlen = 4;
+		parsed->fhuuid = fsid+4;
 		break;
 	case FSID_UUID8: /* 8 byte uuid */
 		if (fsidlen != 8)
-			goto out;
-		uuidlen = 8;
-		fhuuid = fsid;
+			return -1;
+		parsed->uuidlen = 8;
+		parsed->fhuuid = fsid;
 		break;
 	case FSID_UUID16: /* 16 byte uuid */
 		if (fsidlen != 16)
-			goto out;
-		uuidlen = 16;
-		fhuuid = fsid;
+			return -1;
+		parsed->uuidlen = 16;
+		parsed->fhuuid = fsid;
 		break;
 	case FSID_UUID16_INUM: /* 8 byte inode number and 16 byte uuid */
 		if (fsidlen != 24)
-			goto out;
+			return -1;
 		memcpy(&inode64, fsid, 8);
-		inode = inode64;
-		uuidlen = 16;
-		fhuuid = fsid+8;
+		parsed->inode = inode64;
+		parsed->uuidlen = 16;
+		parsed->fhuuid = fsid+8;
 		break;
 	}
+	return 0;
+}
+
+static bool match_fsid(struct parsed_fsid *parsed, nfs_export *exp, char *path)
+{
+	struct stat stb;
+	int type;
+	char u[16];
+
+	if (stat(path, &stb) != 0)
+		return false;
+	if (!S_ISDIR(stb.st_mode) && !S_ISREG(stb.st_mode))
+		return false;
+
+	switch (parsed->fsidtype) {
+	case FSID_DEV:
+	case FSID_MAJOR_MINOR:
+	case FSID_ENCODE_DEV:
+		if (stb.st_ino != parsed->inode)
+			return false;
+		if (parsed->major != major(stb.st_dev) ||
+		    parsed->minor != minor(stb.st_dev))
+			return false;
+		return true;
+	case FSID_NUM:
+		if (((exp->m_export.e_flags & NFSEXP_FSID) == 0 ||
+		     exp->m_export.e_fsid != parsed->fsidnum))
+			return false;
+		return true;
+	case FSID_UUID4_INUM:
+	case FSID_UUID16_INUM:
+		if (stb.st_ino != parsed->inode)
+			return false;
+		goto check_uuid;
+	case FSID_UUID8:
+	case FSID_UUID16:
+		if (!is_mountpoint(path))
+			return false;
+	check_uuid:
+		if (exp->m_export.e_uuid)
+			get_uuid(exp->m_export.e_uuid, parsed->uuidlen, u);
+		else
+			for (type = 0;
+			     uuid_by_path(path, type, parsed->uuidlen, u);
+			     type++)
+				if (memcmp(u, parsed->fhuuid, parsed->uuidlen) == 0)
+					return true;
+
+		if (memcmp(u, parsed->fhuuid, parsed->uuidlen) != 0)
+			return false;
+		return true;
+	}
+	/* Well, unreachable, actually: */
+	return false;
+}
+
+static void nfsd_fh(FILE *f)
+{
+	/* request are:
+	 *  domain fsidtype fsid
+	 * interpret fsid, find export point and options, and write:
+	 *  domain fsidtype fsid expiry path
+	 */
+	char *cp;
+	char *dom;
+	int fsidtype;
+	int fsidlen;
+	char fsid[32];
+	struct parsed_fsid parsed;
+	struct exportent *found = NULL;
+	struct addrinfo *ai = NULL;
+	char *found_path = NULL;
+	nfs_export *exp;
+	int i;
+	int dev_missing = 0;
+
+	if (readline(fileno(f), &lbuf, &lbuflen) != 1)
+		return;
+
+	xlog(D_CALL, "nfsd_fh: inbuf '%s'", lbuf);
+
+	cp = lbuf;
+
+	dom = malloc(strlen(cp));
+	if (dom == NULL)
+		return;
+	if (qword_get(&cp, dom, strlen(cp)) <= 0)
+		goto out;
+	if (qword_get_int(&cp, &fsidtype) != 0)
+		goto out;
+	if (fsidtype < 0 || fsidtype > 7)
+		goto out; /* unknown type */
+	if ((fsidlen = qword_get(&cp, fsid, 32)) <= 0)
+		goto out;
+	if (parse_fsid(fsidtype, fsidlen, fsid, &parsed))
+		goto out;
 
 	auth_reload();
 
@@ -458,10 +542,7 @@ static void nfsd_fh(FILE *f)
 	for (i=0 ; i < MCL_MAXTYPES; i++) {
 		nfs_export *next_exp;
 		for (exp = exportlist[i].p_head; exp; exp = next_exp) {
-			struct stat stb;
-			char u[16];
 			char *path;
-			int type;
 
 			if (exp->m_export.e_flags & NFSEXP_CROSSMOUNT) {
 				static nfs_export *prev = NULL;
@@ -494,50 +575,9 @@ static void nfsd_fh(FILE *f)
 					   exp->m_export.e_mountpoint:
 					   exp->m_export.e_path))
 				dev_missing ++;
-			if (stat(path, &stb) != 0)
-				continue;
-			if (!S_ISDIR(stb.st_mode) && !S_ISREG(stb.st_mode)) {
+
+			if (!match_fsid(&parsed, exp, path))
 				continue;
-			}
-			switch(fsidtype){
-			case FSID_DEV:
-			case FSID_MAJOR_MINOR:
-			case FSID_ENCODE_DEV:
-				if (stb.st_ino != inode)
-					continue;
-				if (major != major(stb.st_dev) ||
-				    minor != minor(stb.st_dev))
-					continue;
-				break;
-			case FSID_NUM:
-				if (((exp->m_export.e_flags & NFSEXP_FSID) == 0 ||
-				     exp->m_export.e_fsid != fsidnum))
-					continue;
-				break;
-			case FSID_UUID4_INUM:
-			case FSID_UUID16_INUM:
-				if (stb.st_ino != inode)
-					continue;
-				goto check_uuid;
-			case FSID_UUID8:
-			case FSID_UUID16:
-				if (!is_mountpoint(path))
-					continue;
-			check_uuid:
-				if (exp->m_export.e_uuid)
-					get_uuid(exp->m_export.e_uuid,
-						 uuidlen, u);
-				else
-					for (type = 0;
-					     uuid_by_path(path, type, uuidlen, u);
-					     type++)
-						if (memcmp(u, fhuuid, uuidlen) == 0)
-							break;
-
-				if (memcmp(u, fhuuid, uuidlen) != 0)
-					continue;
-				break;
-			}
 			if (use_ipaddr) {
 				if (ai == NULL) {
 					struct addrinfo *tmp;
@@ -550,16 +590,26 @@ static void nfsd_fh(FILE *f)
 				if (!client_check(exp->m_client, ai))
 					continue;
 			}
-			/* It's a match !! */
-			if (!found) {
+			if (!found || subexport(&exp->m_export, found)) {
 				found = &exp->m_export;
+				free(found_path);
 				found_path = strdup(path);
 				if (found_path == NULL)
 					goto out;
-			} else if (strcmp(found->e_path, exp->m_export.e_path)!= 0)
+			} else if (strcmp(found->e_path, exp->m_export.e_path) != 0
+				   && !subexport(found, &exp->m_export))
 			{
 				xlog(L_WARNING, "%s and %s have same filehandle for %s, using first",
 				     found_path, path, dom);
+			} else {
+				/* same path, if one is V4ROOT, choose the other */
+				if (found->e_flags & NFSEXP_V4ROOT) {
+					found = &exp->m_export;
+					free(found_path);
+					found_path = strdup(path);
+					if (found_path == NULL)
+						goto out;
+				}
 			}
 		}
 	}
@@ -731,10 +781,14 @@ lookup_export(char *dom, char *path, struct addrinfo *ai)
 				found_type = i;
 				continue;
 			}
-
-			/* Always prefer non-V4ROOT mounts */
-			if (found->m_export.e_flags & NFSEXP_V4ROOT)
+			/* Always prefer non-V4ROOT exports */
+			if (exp->m_export.e_flags & NFSEXP_V4ROOT)
+				continue;
+			if (found->m_export.e_flags & NFSEXP_V4ROOT) {
+				found = exp;
+				found_type = i;
 				continue;
+			}
 
 			/* If one is a CROSSMOUNT, then prefer the longest path */
 			if (((found->m_export.e_flags & NFSEXP_CROSSMOUNT) ||
@@ -761,6 +815,229 @@ lookup_export(char *dom, char *path, struct addrinfo *ai)
 	return found;
 }
 
+#ifdef HAVE_NFS_PLUGIN_H
+#include <dlfcn.h>
+#include <nfs-plugin.h>
+
+/*
+ * Walk through a set of FS locations and build a set of export options.
+ * Returns true if all went to plan; otherwise, false.
+ */
+static _Bool
+locations_to_options(struct jp_ops *ops, nfs_fsloc_set_t locations,
+		char *options, size_t remaining, int *ttl)
+{
+	char *server, *last_path, *rootpath, *ptr;
+	_Bool seen = false;
+
+	last_path = NULL;
+	rootpath = NULL;
+	server = NULL;
+	ptr = options;
+	*ttl = 0;
+
+	for (;;) {
+		enum jp_status status;
+		int len;
+
+		status = ops->jp_get_next_location(locations, &server,
+							&rootpath, ttl);
+		if (status == JP_EMPTY)
+			break;
+		if (status != JP_OK) {
+			xlog(D_GENERAL, "%s: failed to parse location: %s",
+				__func__, ops->jp_error(status));
+			goto out_false;
+		}
+		xlog(D_GENERAL, "%s: Location: %s:%s",
+			__func__, server, rootpath);
+
+		if (last_path && strcmp(rootpath, last_path) == 0) {
+			len = snprintf(ptr, remaining, "+%s", server);
+			if (len < 0) {
+				xlog(D_GENERAL, "%s: snprintf: %m", __func__);
+				goto out_false;
+			}
+			if ((size_t)len >= remaining) {
+				xlog(D_GENERAL, "%s: options buffer overflow", __func__);
+				goto out_false;
+			}
+			remaining -= (size_t)len;
+			ptr += len;
+		} else {
+			if (last_path == NULL)
+				len = snprintf(ptr, remaining, "refer=%s@%s",
+							rootpath, server);
+			else
+				len = snprintf(ptr, remaining, ":%s@%s",
+							rootpath, server);
+			if (len < 0) {
+				xlog(D_GENERAL, "%s: snprintf: %m", __func__);
+				goto out_false;
+			}
+			if ((size_t)len >= remaining) {
+				xlog(D_GENERAL, "%s: options buffer overflow",
+					__func__);
+				goto out_false;
+			}
+			remaining -= (size_t)len;
+			ptr += len;
+			last_path = rootpath;
+		}
+
+		seen = true;
+		free(rootpath);
+		free(server);
+	}
+
+	xlog(D_CALL, "%s: options='%s', ttl=%d",
+		__func__, options, *ttl);
+	return seen;
+
+out_false:
+	free(rootpath);
+	free(server);
+	return false;
+}
+
+/*
+ * Walk through the set of FS locations and build an exportent.
+ * Returns pointer to an exportent if "junction" refers to a junction.
+ *
+ * Returned exportent points to static memory.
+ */
+static struct exportent *do_locations_to_export(struct jp_ops *ops,
+		nfs_fsloc_set_t locations, const char *junction,
+		char *options, size_t options_len)
+{
+	struct exportent *exp;
+	int ttl;
+
+	if (!locations_to_options(ops, locations, options, options_len, &ttl))
+		return NULL;
+
+	exp = mkexportent("*", (char *)junction, options);
+	if (exp == NULL) {
+		xlog(L_ERROR, "%s: Failed to construct exportent", __func__);
+		return NULL;
+	}
+
+	exp->e_uuid = NULL;
+	exp->e_ttl = ttl;
+	return exp;
+}
+
+/*
+ * Convert set of FS locations to an exportent.  Returns pointer to
+ * an exportent if "junction" refers to a junction.
+ *
+ * Returned exportent points to static memory.
+ */
+static struct exportent *locations_to_export(struct jp_ops *ops,
+		nfs_fsloc_set_t locations, const char *junction)
+{
+	struct exportent *exp;
+	char *options;
+
+	options = malloc(BUFSIZ);
+	if (options == NULL) {
+		xlog(D_GENERAL, "%s: failed to allocate options buffer",
+			__func__);
+		return NULL;
+	}
+	options[0] = '\0';
+
+	exp = do_locations_to_export(ops, locations, junction,
+						options, BUFSIZ);
+
+	free(options);
+	return exp;
+}
+
+/*
+ * Retrieve locations information in "junction" and dump it to the
+ * kernel.  Returns pointer to an exportent if "junction" refers
+ * to a junction.
+ *
+ * Returned exportent points to static memory.
+ */
+static struct exportent *invoke_junction_ops(void *handle,
+		const char *junction)
+{
+	nfs_fsloc_set_t locations;
+	struct exportent *exp;
+	enum jp_status status;
+	struct jp_ops *ops;
+	char *error;
+
+	ops = (struct jp_ops *)dlsym(handle, "nfs_junction_ops");
+	error = dlerror();
+	if (error != NULL) {
+		xlog(D_GENERAL, "%s: dlsym(jp_junction_ops): %s",
+			__func__, error);
+		return NULL;
+	}
+	if (ops->jp_api_version != JP_API_VERSION) {
+		xlog(D_GENERAL, "%s: unrecognized junction API version: %u",
+			__func__, ops->jp_api_version);
+		return NULL;
+	}
+
+	status = ops->jp_init(false);
+	if (status != JP_OK) {
+		xlog(D_GENERAL, "%s: failed to resolve %s: %s",
+			__func__, junction, ops->jp_error(status));
+		return NULL;
+	}
+
+	status = ops->jp_get_locations(junction, &locations);
+	if (status != JP_OK) {
+		xlog(D_GENERAL, "%s: failed to resolve %s: %s",
+			__func__, junction, ops->jp_error(status));
+		return NULL;
+	}
+
+	exp = locations_to_export(ops, locations, junction);
+
+	ops->jp_put_locations(locations);
+	ops->jp_done();
+	return exp;
+}
+
+/*
+ * Load the junction plug-in, then try to resolve "pathname".
+ * Returns pointer to an initialized exportent if "junction"
+ * refers to a junction, or NULL if not.
+ *
+ * Returned exportent points to static memory.
+ */
+static struct exportent *lookup_junction(const char *pathname)
+{
+	struct exportent *exp;
+	void *handle;
+
+	handle = dlopen("libnfsjunct.so", RTLD_NOW);
+	if (handle == NULL) {
+		xlog(D_GENERAL, "%s: dlopen: %s", __func__, dlerror());
+		return NULL;
+	}
+	(void)dlerror();	/* Clear any error */
+
+	exp = invoke_junction_ops(handle, pathname);
+
+	/* We could leave it loaded to make junction resolution
+	 * faster next time.  However, if we want to replace the
+	 * library, that would require restarting mountd. */
+	(void)dlclose(handle);
+	return exp;
+}
+#else	/* !HAVE_NFS_PLUGIN_H */
+static inline struct exportent *lookup_junction(const char *UNUSED(pathname))
+{
+	return NULL;
+}
+#endif	/* !HAVE_NFS_PLUGIN_H */
+
 static void nfsd_export(FILE *f)
 {
 	/* requests are:
@@ -813,7 +1090,7 @@ static void nfsd_export(FILE *f)
 			dump_to_cache(f, dom, path, NULL);
 		}
 	} else {
-		dump_to_cache(f, dom, path, NULL);
+		dump_to_cache(f, dom, path, lookup_junction(path));
 	}
  out:
 	xlog(D_CALL, "nfsd_export: found %p path %s", found, path ? path : NULL);