X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Fnetlink.c;h=5414239c794ecf4254f0830a7c2c62943fc1231d;hb=bee6b8bc16b1c42fef8843cffe4d68b464cddadf;hp=1e1ec61f6c1fc3d06718031acf4dc2f630c2b006;hpb=506564b8cf00ea42d3b9b818a6b7a33800f07d31;p=openvswitch diff --git a/lib/netlink.c b/lib/netlink.c index 1e1ec61f..5414239c 100644 --- a/lib/netlink.c +++ b/lib/netlink.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks. + * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. @@ -88,26 +88,6 @@ nl_msg_reserve(struct ofpbuf *msg, size_t size) ofpbuf_prealloc_tailroom(msg, NLMSG_ALIGN(size)); } -static uint32_t -get_nlmsg_seq(void) -{ - /* Next nlmsghdr sequence number. - * - * This implementation uses sequence numbers that are unique process-wide, - * to avoid a hypothetical race: send request, close socket, open new - * socket that reuses the old socket's PID value, send request on new - * socket, receive reply from kernel to old socket but with same PID and - * sequence number. (This race could be avoided other ways, e.g. by - * preventing PIDs from being quickly reused). */ - static uint32_t next_seq; - - if (next_seq == 0) { - /* Pick initial sequence number. */ - next_seq = getpid() ^ time_wall(); - } - return next_seq++; -} - /* Puts a nlmsghdr at the beginning of 'msg', which must be initially empty. * Uses the given 'type' and 'flags'. 'expected_payload' should be * an estimate of the number of payload bytes to be supplied; if the size of @@ -121,8 +101,9 @@ get_nlmsg_seq(void) * is often NLM_F_REQUEST indicating that a request is being made, commonly * or'd with NLM_F_ACK to request an acknowledgement. * - * Sets the new nlmsghdr's nlmsg_pid field to 0 for now. nl_sock_send() will - * fill it in just before sending the message. + * Sets the new nlmsghdr's nlmsg_len, nlmsg_seq, and nlmsg_pid fields to 0 for + * now. Functions that send Netlink messages will fill these in just before + * sending the message. * * nl_msg_put_genlmsghdr() is more convenient for composing a Generic Netlink * message. */ @@ -139,7 +120,7 @@ nl_msg_put_nlmsghdr(struct ofpbuf *msg, nlmsghdr->nlmsg_len = 0; nlmsghdr->nlmsg_type = type; nlmsghdr->nlmsg_flags = flags; - nlmsghdr->nlmsg_seq = get_nlmsg_seq(); + nlmsghdr->nlmsg_seq = 0; nlmsghdr->nlmsg_pid = 0; } @@ -620,6 +601,51 @@ static const size_t attr_len_range[][2] = { [NL_A_NESTED] = { 0, SIZE_MAX }, }; +bool +nl_attr_validate(const struct nlattr *nla, const struct nl_policy *policy) +{ + uint16_t type = nl_attr_type(nla); + size_t min_len; + size_t max_len; + size_t len; + + if (policy->type == NL_A_NO_ATTR) { + return true; + } + + /* Figure out min and max length. */ + min_len = policy->min_len; + if (!min_len) { + min_len = attr_len_range[policy->type][0]; + } + max_len = policy->max_len; + if (!max_len) { + max_len = attr_len_range[policy->type][1]; + } + + /* Verify length. */ + len = nl_attr_get_size(nla); + if (len < min_len || len > max_len) { + VLOG_DBG_RL(&rl, "attr %"PRIu16" length %zu not in " + "allowed range %zu...%zu", type, len, min_len, max_len); + return false; + } + + /* Strings must be null terminated and must not have embedded nulls. */ + if (policy->type == NL_A_STRING) { + if (((char *) nla)[nla->nla_len - 1]) { + VLOG_DBG_RL(&rl, "attr %"PRIu16" lacks null at end", type); + return false; + } + if (memchr(nla + 1, '\0', len - 1) != NULL) { + VLOG_DBG_RL(&rl, "attr %"PRIu16" has bad length", type); + return false; + } + } + + return true; +} + /* Parses the 'msg' starting at the given 'nla_offset' as a sequence of Netlink * attributes. 'policy[i]', for 0 <= i < n_attrs, specifies how the attribute * with nla_type == i is parsed; a pointer to attribute i is stored in @@ -633,21 +659,10 @@ nl_policy_parse(const struct ofpbuf *msg, size_t nla_offset, struct nlattr *attrs[], size_t n_attrs) { struct nlattr *nla; - size_t n_required; size_t left; size_t i; - n_required = 0; - for (i = 0; i < n_attrs; i++) { - attrs[i] = NULL; - - assert(policy[i].type < N_NL_ATTR_TYPES); - if (policy[i].type != NL_A_NO_ATTR - && policy[i].type != NL_A_FLAG - && !policy[i].optional) { - n_required++; - } - } + memset(attrs, 0, n_attrs * sizeof *attrs); if (msg->size < nla_offset) { VLOG_DBG_RL(&rl, "missing headers in nl_policy_parse"); @@ -656,54 +671,31 @@ nl_policy_parse(const struct ofpbuf *msg, size_t nla_offset, NL_ATTR_FOR_EACH (nla, left, (struct nlattr *) ((char *) msg->data + nla_offset), - msg->size - nla_offset) { - size_t offset = (char*)nla - (char*)msg->data; - size_t len = nl_attr_get_size(nla); + msg->size - nla_offset) + { uint16_t type = nl_attr_type(nla); if (type < n_attrs && policy[type].type != NL_A_NO_ATTR) { const struct nl_policy *e = &policy[type]; - size_t min_len, max_len; - - /* Validate length and content. */ - min_len = e->min_len ? e->min_len : attr_len_range[e->type][0]; - max_len = e->max_len ? e->max_len : attr_len_range[e->type][1]; - if (len < min_len || len > max_len) { - VLOG_DBG_RL(&rl, "%zu: attr %"PRIu16" length %zu not in " - "allowed range %zu...%zu", - offset, type, len, min_len, max_len); + if (!nl_attr_validate(nla, e)) { return false; } - if (e->type == NL_A_STRING) { - if (((char *) nla)[nla->nla_len - 1]) { - VLOG_DBG_RL(&rl, "%zu: attr %"PRIu16" lacks null at end", - offset, type); - return false; - } - if (memchr(nla + 1, '\0', len - 1) != NULL) { - VLOG_DBG_RL(&rl, "%zu: attr %"PRIu16" has bad length", - offset, type); - return false; - } - } - if (!e->optional && attrs[type] == NULL) { - assert(n_required > 0); - --n_required; - } if (attrs[type]) { - VLOG_DBG_RL(&rl, "%zu: duplicate attr %"PRIu16, offset, type); + VLOG_DBG_RL(&rl, "duplicate attr %"PRIu16, type); } attrs[type] = nla; - } else { - /* Skip attribute type that we don't care about. */ } } if (left) { VLOG_DBG_RL(&rl, "attributes followed by garbage"); return false; } - if (n_required) { - VLOG_DBG_RL(&rl, "%zu required attrs missing", n_required); - return false; + + for (i = 0; i < n_attrs; i++) { + const struct nl_policy *e = &policy[i]; + if (!e->optional && e->type != NL_A_NO_ATTR && !attrs[i]) { + VLOG_DBG_RL(&rl, "required attr %zu missing", i); + return false; + } } return true; } @@ -729,7 +721,7 @@ nl_attr_find__(const struct nlattr *attrs, size_t size, uint16_t type) size_t left; NL_ATTR_FOR_EACH (nla, left, attrs, size) { - if (nl_attr_type (nla) == type) { + if (nl_attr_type(nla) == type) { return nla; } }