[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v4 15/19] tools/xenstore: merge is_valid_nodename() into canonicalize()
Today is_valid_nodename() is always called directly after calling canonicalize(), with the exception of do_unwatch(), where the call is missing (which is not correct, but results just in a wrong error reason being returned). Merge is_valid_nodename() into canonicalize(). While at it merge valid_chars() into it, too. Signed-off-by: Juergen Gross <jgross@xxxxxxxx> --- V3: - new patch V4: - make name const in canonicalize() - don't merge valid_chars() (Julien Grall) - free full path string in case of error (Julien Grall) --- tools/xenstore/xenstored_core.c | 85 +++++++++++++++++--------------- tools/xenstore/xenstored_core.h | 6 +-- tools/xenstore/xenstored_watch.c | 16 ++---- 3 files changed, 50 insertions(+), 57 deletions(-) diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c index 0ebe4bb7d2..69e147df2c 100644 --- a/tools/xenstore/xenstored_core.c +++ b/tools/xenstore/xenstored_core.c @@ -1219,33 +1219,6 @@ static bool valid_chars(const char *node) "0123456789-/_@") == strlen(node)); } -bool is_valid_nodename(const struct connection *conn, const char *node, - bool allow_special) -{ - int local_off = 0; - unsigned int domid; - - /* Must start in / or - if special nodes are allowed - in @. */ - if (!strstarts(node, "/") && (!allow_special || !strstarts(node, "@"))) - return false; - - /* Cannot end in / (unless it's just "/"). */ - if (strends(node, "/") && !streq(node, "/")) - return false; - - /* No double //. */ - if (strstr(node, "//")) - return false; - - if (sscanf(node, "/local/domain/%5u/%n", &domid, &local_off) != 1) - local_off = 0; - - if (domain_max_chk(conn, ACC_PATHLEN, strlen(node) - local_off)) - return false; - - return valid_chars(node); -} - /* We expect one arg in the input: return NULL otherwise. * The payload must contain exactly one nul, at the end. */ @@ -1278,16 +1251,51 @@ static char *node_perms_to_strings(const struct node *node, unsigned int *len) } const char *canonicalize(struct connection *conn, const void *ctx, - const char *node) + const char *node, bool allow_special) { - const char *prefix; + const char *name; + int local_off = 0; + unsigned int domid; - if (!node || (node[0] == '/') || (node[0] == '@')) - return node; - prefix = get_implicit_path(conn); - if (prefix) - return talloc_asprintf(ctx, "%s/%s", prefix, node); - return node; + /* + * Invalid if any of: + * - no node at all + * - illegal character in node + * - starts with '@' but no special node allowed + */ + errno = EINVAL; + if (!node || + !valid_chars(node) || + (node[0] == '@' && !allow_special)) + return NULL; + + if (node[0] != '/' && node[0] != '@') { + name = talloc_asprintf(ctx, "%s/%s", get_implicit_path(conn), + node); + if (!name) + return NULL; + } else + name = node; + + if (sscanf(name, "/local/domain/%5u/%n", &domid, &local_off) != 1) + local_off = 0; + + /* + * Only valid if: + * - doesn't end in / (unless it's just "/") + * - no double // + * - not violating max allowed path length + */ + if (!(strends(name, "/") && !streq(name, "/")) && + !strstr(name, "//") && + !domain_max_chk(conn, ACC_PATHLEN, strlen(name) - local_off)) + return name; + + /* Release the memory if 'name' was allocated by us. */ + if (name != node) + talloc_free(name); + + return NULL; } static struct node *get_node_canonicalized(struct connection *conn, @@ -1301,13 +1309,10 @@ static struct node *get_node_canonicalized(struct connection *conn, if (!canonical_name) canonical_name = &tmp_name; - *canonical_name = canonicalize(conn, ctx, name); + *canonical_name = canonicalize(conn, ctx, name, allow_special); if (!*canonical_name) return NULL; - if (!is_valid_nodename(conn, *canonical_name, allow_special)) { - errno = EINVAL; - return NULL; - } + return get_node(conn, ctx, *canonical_name, perm); } diff --git a/tools/xenstore/xenstored_core.h b/tools/xenstore/xenstored_core.h index 5575cc0689..ad87199042 100644 --- a/tools/xenstore/xenstored_core.h +++ b/tools/xenstore/xenstored_core.h @@ -241,7 +241,7 @@ void send_ack(struct connection *conn, enum xsd_sockmsg_type type); /* Canonicalize this path if possible. */ const char *canonicalize(struct connection *conn, const void *ctx, - const char *node); + const char *node, bool allow_special); /* Get access permissions. */ unsigned int perm_for_conn(struct connection *conn, @@ -304,10 +304,6 @@ struct connection *get_connection_by_id(unsigned int conn_id); void check_store(void); void corrupt(struct connection *conn, const char *fmt, ...); -/* Is this a valid node name? */ -bool is_valid_nodename(const struct connection *conn, const char *node, - bool allow_special); - /* Get name of parent node. */ char *get_parent(const void *ctx, const char *node); diff --git a/tools/xenstore/xenstored_watch.c b/tools/xenstore/xenstored_watch.c index e695762c64..7d4d097cf9 100644 --- a/tools/xenstore/xenstored_watch.c +++ b/tools/xenstore/xenstored_watch.c @@ -164,17 +164,9 @@ static int check_watch_path(struct connection *conn, const void *ctx, const char **path, bool *relative) { *relative = !strstarts(*path, "/") && !strstarts(*path, "@"); - *path = canonicalize(conn, ctx, *path); - if (!*path) - return errno; - if (!is_valid_nodename(conn, *path, true)) - goto inval; - - return 0; + *path = canonicalize(conn, ctx, *path, true); - inval: - errno = EINVAL; - return errno; + return *path ? 0 : errno; } static struct watch *add_watch(struct connection *conn, const char *path, @@ -258,9 +250,9 @@ int do_unwatch(const void *ctx, struct connection *conn, if (get_strings(in, vec, ARRAY_SIZE(vec)) != ARRAY_SIZE(vec)) return EINVAL; - node = canonicalize(conn, ctx, vec[0]); + node = canonicalize(conn, ctx, vec[0], true); if (!node) - return ENOMEM; + return errno; list_for_each_entry(watch, &conn->watches, list) { if (streq(watch->node, node) && streq(watch->token, vec[1])) { list_del(&watch->list); -- 2.35.3
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