[v2,16/18] tools/xenstore: don't use struct node_perms in struct node

Message ID	20230710065947.4201-17-jgross@suse.com (mailing list archive)
State	Superseded
Headers	show Return-Path: <xen-devel-bounces@lists.xenproject.org> Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" <xen-devel-bounces@lists.xenproject.org> From: Juergen Gross <jgross@suse.com> To: xen-devel@lists.xenproject.org Cc: Juergen Gross <jgross@suse.com>, Wei Liu <wl@xen.org>, Julien Grall <julien@xen.org>, Anthony PERARD <anthony.perard@citrix.com> Subject: [PATCH v2 16/18] tools/xenstore: don't use struct node_perms in struct node Date: Mon, 10 Jul 2023 08:59:45 +0200 Message-Id: <20230710065947.4201-17-jgross@suse.com> In-Reply-To: <20230710065947.4201-1-jgross@suse.com> References: <20230710065947.4201-1-jgross@suse.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit
Series	tools/xenstore: drop TDB \| expand [v2,00/18] tools/xenstore: drop TDB [v2,01/18] tools/xenstore: explicitly specify create or modify for tdb_store() [v2,02/18] tools/xenstore: replace key in struct node with data base name [v2,03/18] tools/xenstore: let transaction_prepend() return the name for access [v2,04/18] tools/xenstore: rename do_tdb_delete() and change parameter type [v2,05/18] tools/xenstore: rename do_tdb_write() and change parameter type [v2,06/18] tools/xenstore: switch get_acc_data() to use name instead of key [v2,07/18] tools/xenstore: add wrapper for tdb_fetch() [v2,08/18] tools/xenstore: make hashtable key and value parameters const [v2,09/18] tools/xenstore: let hashtable_add() fail in case of existing entry [v2,10/18] tools/xenstore: add hashtable_replace() function [v2,11/18] tools/xenstore: drop use of tdb [v2,12/18] tools/xenstore: remove tdb code [v2,13/18] tools/xenstore: let db_delete() return void [v2,14/18] tools/xenstore: move copying of node data out of db_fetch() [v2,15/18] tools/xenstore: rework struct xs_tdb_record_hdr [v2,16/18] tools/xenstore: don't use struct node_perms in struct node [v2,17/18] tools/xenstore: use struct node_hdr in struct node [v2,18/18] tools/xenstore: add nocopy flag to node read functions

diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c index d886d66dd6..9f0e56a149 100644 --- a/tools/xenstore/xenstored_core.c +++ b/tools/xenstore/xenstored_core.c @@ -735,7 +735,7 @@ struct node *read_node(struct connection *conn, const void *ctx, /* Datalen, childlen, number of permissions */ node->generation = hdr->generation; - node->perms.num = hdr->num_perms; + node->num_perms = hdr->num_perms; node->datalen = hdr->datalen; node->childlen = hdr->childlen; node->acc.domid = perms_from_node_hdr(hdr)->id; @@ -743,12 +743,12 @@ struct node *read_node(struct connection *conn, const void *ctx, /* Copy node data to new memory area, starting with permissions. */ size -= sizeof(*hdr); - node->perms.p = talloc_size(node, size); - if (node->perms.p == NULL) { + node->perms = talloc_size(node, size); + if (node->perms == NULL) { errno = ENOMEM; goto error; } - memcpy(node->perms.p, perms_from_node_hdr(hdr), size); + memcpy(node->perms, perms_from_node_hdr(hdr), size); /* Permissions are struct xs_permissions. */ if (domain_adjust_node_perms(node)) @@ -759,7 +759,7 @@ struct node *read_node(struct connection *conn, const void *ctx, node->acc.memory = 0; /* Data is binary blob (usually ascii, no nul). */ - node->data = node->perms.p + hdr->num_perms; + node->data = node->perms + hdr->num_perms; /* Children is strings, nul separated. */ node->children = node->data + node->datalen; @@ -798,7 +798,7 @@ int write_node_raw(struct connection *conn, const char *db_name, return errno; size = sizeof(*hdr) - + node->perms.num * sizeof(node->perms.p[0]) + + node->num_perms * sizeof(node->perms[0]) + node->datalen + node->childlen; /* Call domain_max_chk() in any case in order to record max values. */ @@ -815,13 +815,13 @@ int write_node_raw(struct connection *conn, const char *db_name, hdr = data; hdr->generation = node->generation; - hdr->num_perms = node->perms.num; + hdr->num_perms = node->num_perms; hdr->datalen = node->datalen; hdr->childlen = node->childlen; p = perms_from_node_hdr(hdr); - memcpy(p, node->perms.p, node->perms.num * sizeof(*node->perms.p)); - p += node->perms.num * sizeof(*node->perms.p); + memcpy(p, node->perms, node->num_perms * sizeof(*node->perms)); + p += node->num_perms * sizeof(*node->perms); memcpy(p, node->data, node->datalen); p += node->datalen; memcpy(p, node->children, node->childlen); @@ -902,6 +902,7 @@ static int ask_parents(struct connection *conn, const void *ctx, const char *name, unsigned int *perm) { struct node *node; + struct node_perms perms; do { name = get_parent(ctx, name); @@ -921,7 +922,8 @@ static int ask_parents(struct connection *conn, const void *ctx, return 0; } - *perm = perm_for_conn(conn, &node->perms); + node_to_node_perms(node, &perms); + *perm = perm_for_conn(conn, &perms); return 0; } @@ -958,11 +960,13 @@ static struct node *get_node(struct connection *conn, unsigned int perm) { struct node *node; + struct node_perms perms; node = read_node(conn, ctx, name); /* If we don't have permission, we don't have node. */ if (node) { - if ((perm_for_conn(conn, &node->perms) & perm) != perm) { + node_to_node_perms(node, &perms); + if ((perm_for_conn(conn, &perms) & perm) != perm) { errno = EACCES; node = NULL; } @@ -1432,14 +1436,14 @@ static struct node *construct_node(struct connection *conn, const void *ctx, node->name = talloc_steal(node, names[levels - 1]); /* Inherit permissions, unpriv domains own what they create. */ - node->perms.num = parent->perms.num; - node->perms.p = talloc_memdup(node, parent->perms.p, - node->perms.num * - sizeof(*node->perms.p)); - if (!node->perms.p) + node->num_perms = parent->num_perms; + node->perms = talloc_memdup(node, parent->perms, + node->num_perms * + sizeof(*node->perms)); + if (!node->perms) goto nomem; if (domain_is_unprivileged(conn)) - node->perms.p[0].id = conn->id; + node->perms[0].id = conn->id; /* No children, no data */ node->children = node->data = NULL; @@ -1762,12 +1766,14 @@ static int do_get_perms(const void *ctx, struct connection *conn, struct node *node; char *strings; unsigned int len; + struct node_perms perms; node = get_spec_node(conn, ctx, onearg(in), NULL, XS_PERM_READ); if (!node) return errno; - strings = perms_to_strings(node, &node->perms, &len); + node_to_node_perms(node, &perms); + strings = perms_to_strings(node, &perms, &len); if (!strings) return errno; @@ -1815,10 +1821,10 @@ static int do_set_perms(const void *ctx, struct connection *conn, perms.p[0].id != get_node_owner(node)) return EPERM; - old_perms = node->perms; + node_to_node_perms(node, &old_perms); if (domain_nbentry_dec(conn, get_node_owner(node))) return ENOMEM; - node->perms = perms; + node_perms_to_node(&perms, node); if (domain_nbentry_inc(conn, get_node_owner(node))) return ENOMEM; @@ -2330,8 +2336,8 @@ static void manual_node(const char *name, const char *child) barf_perror("Could not allocate initial node %s", name); node->name = name; - node->perms.p = &perms; - node->perms.num = 1; + node->perms = &perms; + node->num_perms = 1; node->children = (char *)child; if (child) node->childlen = strlen(child) + 1; @@ -3202,10 +3208,10 @@ static int dump_state_node(const void *ctx, struct connection *conn, sn.conn_id = 0; sn.ta_id = 0; sn.ta_access = 0; - sn.perm_n = node->perms.num; + sn.perm_n = node->num_perms; sn.path_len = pathlen; sn.data_len = node->datalen; - head.length += node->perms.num * sizeof(*sn.perms); + head.length += node->num_perms * sizeof(*sn.perms); head.length += pathlen; head.length += node->datalen; head.length = ROUNDUP(head.length, 3); @@ -3215,7 +3221,7 @@ static int dump_state_node(const void *ctx, struct connection *conn, if (fwrite(&sn, sizeof(sn), 1, fp) != 1) return dump_state_node_err(data, "Dump node state error"); - ret = dump_state_node_perms(fp, node->perms.p, node->perms.num); + ret = dump_state_node_perms(fp, node->perms, node->num_perms); if (ret) return dump_state_node_err(data, ret); @@ -3412,29 +3418,29 @@ void read_state_node(const void *ctx, const void *state) node->data = name + sn->path_len; node->childlen = 0; node->children = NULL; - node->perms.num = sn->perm_n; - node->perms.p = talloc_array(node, struct xs_permissions, - node->perms.num); - if (!node->perms.p) + node->num_perms = sn->perm_n; + node->perms = talloc_array(node, struct xs_permissions, + node->num_perms); + if (!node->perms) barf("allocation error restoring node"); - for (i = 0; i < node->perms.num; i++) { + for (i = 0; i < node->num_perms; i++) { switch (sn->perms[i].access) { case 'r': - node->perms.p[i].perms = XS_PERM_READ; + node->perms[i].perms = XS_PERM_READ; break; case 'w': - node->perms.p[i].perms = XS_PERM_WRITE; + node->perms[i].perms = XS_PERM_WRITE; break; case 'b': - node->perms.p[i].perms = XS_PERM_READ | XS_PERM_WRITE; + node->perms[i].perms = XS_PERM_READ | XS_PERM_WRITE; break; default: - node->perms.p[i].perms = XS_PERM_NONE; + node->perms[i].perms = XS_PERM_NONE; break; } if (sn->perms[i].flags & XS_STATE_NODE_PERM_IGNORE) - node->perms.p[i].perms |= XS_PERM_IGNORE; - node->perms.p[i].id = sn->perms[i].domid; + node->perms[i].perms |= XS_PERM_IGNORE; + node->perms[i].id = sn->perms[i].domid; } if (!strstarts(name, "@")) { diff --git a/tools/xenstore/xenstored_core.h b/tools/xenstore/xenstored_core.h index 968b6f843c..c706d30b63 100644 --- a/tools/xenstore/xenstored_core.h +++ b/tools/xenstore/xenstored_core.h @@ -209,7 +209,8 @@ struct node { #define NO_GENERATION ~((uint64_t)0) /* Permissions. */ - struct node_perms perms; + unsigned int num_perms; + struct xs_permissions *perms; /* Contents. */ unsigned int datalen; @@ -250,7 +251,23 @@ unsigned int perm_for_conn(struct connection *conn, /* Get owner of a node. */ static inline unsigned int get_node_owner(const struct node *node) { - return node->perms.p[0].id; + return node->perms[0].id; +} + +/* Transfer permissions from node to struct node_perms. */ +static inline void node_to_node_perms(const struct node *node, + struct node_perms *perms) +{ + perms->num = node->num_perms; + perms->p = node->perms; +} + +/* Transfer permissions from struct node_perms to node. */ +static inline void node_perms_to_node(const struct node_perms *perms, + struct node *node) +{ + node->num_perms = perms->num; + node->perms = perms->p; } /* Write a node to the data base. */ diff --git a/tools/xenstore/xenstored_domain.c b/tools/xenstore/xenstored_domain.c index d8810fa353..b17402fe11 100644 --- a/tools/xenstore/xenstored_domain.c +++ b/tools/xenstore/xenstored_domain.c @@ -513,12 +513,12 @@ static int domain_tree_remove_sub(const void *ctx, struct connection *conn, struct domain *domain = arg; int ret = WALK_TREE_OK; - if (node->perms.p[0].id != domain->domid) + if (node->perms[0].id != domain->domid) return WALK_TREE_OK; if (keep_orphans) { domain_nbentry_dec(NULL, domain->domid); - node->perms.p[0].id = priv_domid; + node->perms[0].id = priv_domid; node->acc.memory = 0; domain_nbentry_inc(NULL, priv_domid); if (write_node_raw(NULL, node->name, node, NODE_MODIFY, true)) { @@ -1335,12 +1335,11 @@ int domain_adjust_node_perms(struct node *node) { unsigned int i; - for (i = 1; i < node->perms.num; i++) { - if (node->perms.p[i].perms & XS_PERM_IGNORE) + for (i = 1; i < node->num_perms; i++) { + if (node->perms[i].perms & XS_PERM_IGNORE) continue; - if (!chk_domain_generation(node->perms.p[i].id, - node->generation)) - node->perms.p[i].perms |= XS_PERM_IGNORE; + if (!chk_domain_generation(node->perms[i].id, node->generation)) + node->perms[i].perms |= XS_PERM_IGNORE; } return 0; diff --git a/tools/xenstore/xenstored_transaction.c b/tools/xenstore/xenstored_transaction.c index 77c14f4c24..e39df3a82d 100644 --- a/tools/xenstore/xenstored_transaction.c +++ b/tools/xenstore/xenstored_transaction.c @@ -259,13 +259,13 @@ int access_node(struct connection *conn, struct node *node, if (!i->trans_name) goto nomem; i->node = strchr(i->trans_name, '/') + 1; - if (node->generation != NO_GENERATION && node->perms.num) { + if (node->generation != NO_GENERATION && node->num_perms) { i->perms.p = talloc_array(i, struct xs_permissions, - node->perms.num); + node->num_perms); if (!i->perms.p) goto nomem; - i->perms.num = node->perms.num; - memcpy(i->perms.p, node->perms.p, + i->perms.num = node->num_perms; + memcpy(i->perms.p, node->perms, i->perms.num * sizeof(*i->perms.p)); } diff --git a/tools/xenstore/xenstored_watch.c b/tools/xenstore/xenstored_watch.c index 4195c59e17..10645f762d 100644 --- a/tools/xenstore/xenstored_watch.c +++ b/tools/xenstore/xenstored_watch.c @@ -79,6 +79,7 @@ static bool watch_permitted(struct connection *conn, const void *ctx, unsigned int perm; struct node *parent; char *parent_name; + struct node_perms node_perms; if (perms) { perm = perm_for_conn(conn, perms); @@ -92,7 +93,8 @@ static bool watch_permitted(struct connection *conn, const void *ctx, return false; } - perm = perm_for_conn(conn, &node->perms); + node_to_node_perms(node, &node_perms); + perm = perm_for_conn(conn, &node_perms); if (perm & XS_PERM_READ) return true; @@ -106,7 +108,8 @@ static bool watch_permitted(struct connection *conn, const void *ctx, return false; } - perm = perm_for_conn(conn, &parent->perms); + node_to_node_perms(parent, &node_perms); + perm = perm_for_conn(conn, &node_perms); return perm & XS_PERM_READ; }

[v2,16/18] tools/xenstore: don't use struct node_perms in struct node

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Patch