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Fri, 11 Apr 2025 09:11:04 -0400 X-MC-Unique: JB9pUWNcM5-Y1UQZVpadAg-1 X-Mimecast-MFC-AGG-ID: JB9pUWNcM5-Y1UQZVpadAg_1744377063 Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 5944A195608D for ; Fri, 11 Apr 2025 13:11:03 +0000 (UTC) Received: from lenovo-t14s.redhat.com (unknown [10.44.32.165]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 39F2419560AD; Fri, 11 Apr 2025 13:11:01 +0000 (UTC) From: Laurent Vivier To: passt-dev@passt.top Subject: [PATCH v2 16/20] dhcpv6: Use iov_tail in dhcpv6_opt() Date: Fri, 11 Apr 2025 15:10:26 +0200 Message-ID: <20250411131031.1398006-17-lvivier@redhat.com> In-Reply-To: <20250411131031.1398006-1-lvivier@redhat.com> References: <20250411131031.1398006-1-lvivier@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: P2y2hN20yhA8ikismuurkJ778lW7F6sgsRTKpWEIRlY_1744377063 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit content-type: text/plain; charset="US-ASCII"; x-default=true Message-ID-Hash: IOWK5UNOKRASDUSZXGYYYQSHPLW67OOT X-Message-ID-Hash: IOWK5UNOKRASDUSZXGYYYQSHPLW67OOT X-MailFrom: lvivier@redhat.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: Laurent Vivier X-Mailman-Version: 3.3.8 Precedence: list List-Id: Development discussion and patches for passt Archived-At: Archived-At: List-Archive: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Signed-off-by: Laurent Vivier --- dhcpv6.c | 179 ++++++++++++++++++++++++++++++++----------------------- iov.c | 1 - 2 files changed, 103 insertions(+), 77 deletions(-) diff --git a/dhcpv6.c b/dhcpv6.c index cf5c77d5af72..6458697d348e 100644 --- a/dhcpv6.c +++ b/dhcpv6.c @@ -278,112 +278,122 @@ static struct resp_not_on_link_t { /** * dhcpv6_opt() - Get option from DHCPv6 message - * @p: Packet pool, single packet with UDP header - * @offset: Offset to look at, 0: end of header, set to option start + * @data: Data to look at (input/output) * @type: Option type to look up, network order * - * Return: pointer to option header, or NULL on malformed or missing option + * Return: true if found and @data points to the option header, + * or false on malformed or missing option and @data is + * unmodified. */ -static struct opt_hdr *dhcpv6_opt(const struct pool *p, size_t *offset, - uint16_t type) +static bool dhcpv6_opt(struct iov_tail *data, uint16_t type) { - struct opt_hdr *o; - size_t left; + struct iov_tail head = *data; + const struct opt_hdr *o; + struct opt_hdr oc; - ASSERT(*offset >= UDP_MSG_HDR_SIZE); - - while ((o = packet_get_try(p, 0, *offset, sizeof(*o), &left))) { + while ((o = IOV_PEEK_HEADER(data, oc))) { unsigned int opt_len = ntohs(o->l) + sizeof(*o); - if (ntohs(o->l) > left) - return NULL; + if (opt_len > iov_tail_size(data)) + break; if (o->t == type) - return o; + return true; - *offset += opt_len; + iov_tail_drop(data, opt_len); } - return NULL; + *data = head; + return false; } /** * dhcpv6_ia_notonlink() - Check if any IA contains non-appropriate addresses - * @p: Packet pool, single packet starting from UDP header + * @data: Data to look at, packet starting from UDP header (input/output) * @la: Address we want to lease to the client * - * Return: pointer to non-appropriate IA_NA or IA_TA, if any, NULL otherwise + * Return: true and @data points to non-appropriate IA_NA or IA_TA, if any, + * false otherwise and @data is unmodified */ -static struct opt_hdr *dhcpv6_ia_notonlink(const struct pool *p, - struct in6_addr *la) +static bool dhcpv6_ia_notonlink(struct iov_tail *data, + struct in6_addr *la) { int ia_types[2] = { OPT_IA_NA, OPT_IA_TA }, *ia_type; const struct opt_ia_addr *opt_addr; + struct iov_tail current, ia_base; + struct opt_ia_addr opt_addrc; char buf[INET6_ADDRSTRLEN]; + const struct opt_ia_na *ia; struct in6_addr req_addr; const struct opt_hdr *h; - struct opt_hdr *ia; - size_t offset; + struct opt_ia_na iac; + struct opt_hdr hc; foreach(ia_type, ia_types) { - offset = UDP_MSG_HDR_SIZE; - while ((ia = dhcpv6_opt(p, &offset, *ia_type))) { - if (ntohs(ia->l) < OPT_VSIZE(ia_na)) - return NULL; - - offset += sizeof(struct opt_ia_na); - - while ((h = dhcpv6_opt(p, &offset, OPT_IAAADR))) { - if (ntohs(h->l) != OPT_VSIZE(ia_addr)) - return NULL; - - opt_addr = (const struct opt_ia_addr *)h; + current = *data; + while (dhcpv6_opt(¤t, *ia_type)) { + ia_base = current; + ia = IOV_REMOVE_HEADER(¤t, iac); + if (!ia || ntohs(ia->hdr.l) < OPT_VSIZE(ia_na)) + goto notfound; + + while (dhcpv6_opt(¤t, OPT_IAAADR)) { + h = IOV_PEEK_HEADER(¤t, hc); + if (!h || ntohs(h->l) != OPT_VSIZE(ia_addr)) + goto notfound; + + opt_addr = IOV_REMOVE_HEADER(¤t, + opt_addrc); req_addr = opt_addr->addr; if (!IN6_ARE_ADDR_EQUAL(la, &req_addr)) - goto err; - - offset += sizeof(struct opt_ia_addr); + goto notonlink; } } } - return NULL; +notfound: + return false; -err: +notonlink: info("DHCPv6: requested address %s not on link", inet_ntop(AF_INET6, &req_addr, buf, sizeof(buf))); - return ia; + *data = ia_base; + return true; } /** * dhcpv6_send_ia_notonlink() - Send NotOnLink status - * @c: Execution context - * @ia: Pointer to non-appropriate IA_NA or IA_TA - * @client_id: Client ID message option - * xid: Transaction ID for message exchange + * @c: Execution context + * @ia_base: Non-appropriate IA_NA or IA_TA base + * @client_id_base: Client ID message option base + * @len: Client ID length + * @xid: Transaction ID for message exchange */ -static void dhcpv6_send_ia_notonlink(struct ctx *c, struct opt_hdr *ia, - const struct opt_hdr *client_id, - uint32_t xid) +static void dhcpv6_send_ia_notonlink(struct ctx *c, + const struct iov_tail *ia_base, + const struct iov_tail *client_id_base, + int len, uint32_t xid) { const struct in6_addr *src = &c->ip6.our_tap_ll; + struct opt_hdr *ia = (struct opt_hdr *)resp_not_on_link.var; size_t n; info("DHCPv6: received CONFIRM with inappropriate IA," " sending NotOnLink status in REPLY"); - ia->l = htons(OPT_VSIZE(ia_na) + sizeof(sc_not_on_link)); - n = sizeof(struct opt_ia_na); - memcpy(resp_not_on_link.var, ia, n); + iov_to_buf(&ia_base->iov[0], ia_base->cnt, ia_base->off, + resp_not_on_link.var, n); + ia->l = htons(OPT_VSIZE(ia_na) + sizeof(sc_not_on_link)); memcpy(resp_not_on_link.var + n, &sc_not_on_link, sizeof(sc_not_on_link)); n += sizeof(sc_not_on_link); - memcpy(resp_not_on_link.var + n, client_id, - sizeof(struct opt_hdr) + ntohs(client_id->l)); + iov_to_buf(&client_id_base->iov[0], client_id_base->cnt, + client_id_base->off, resp_not_on_link.var + n, + sizeof(struct opt_hdr) + len); - n += sizeof(struct opt_hdr) + ntohs(client_id->l); + n += sizeof(struct opt_hdr) + len; n = offsetof(struct resp_not_on_link_t, var) + n; @@ -472,17 +482,19 @@ search: /** * dhcpv6_client_fqdn_fill() - Fill in client FQDN option + * @data: Data to look at * @c: Execution context * @buf: Response message buffer where options will be appended * @offset: Offset in message buffer for new options * * Return: updated length of response message buffer. */ -static size_t dhcpv6_client_fqdn_fill(const struct pool *p, const struct ctx *c, +static size_t dhcpv6_client_fqdn_fill(const struct iov_tail *data, + const struct ctx *c, char *buf, int offset) { - struct opt_client_fqdn const *req_opt; + struct iov_tail current = *data; struct opt_client_fqdn *o; size_t opt_len; @@ -501,13 +513,16 @@ static size_t dhcpv6_client_fqdn_fill(const struct pool *p, const struct ctx *c, o = (struct opt_client_fqdn *)(buf + offset); encode_domain_name(o->domain_name, c->fqdn); - req_opt = (struct opt_client_fqdn *)dhcpv6_opt(p, - &(size_t){ UDP_MSG_HDR_SIZE }, - OPT_CLIENT_FQDN); - if (req_opt && req_opt->flags & 0x01 /* S flag */) - o->flags = 0x02 /* O flag */; - else - o->flags = 0x00; + if (dhcpv6_opt(¤t, OPT_CLIENT_FQDN)) { + struct opt_client_fqdn const *req_opt; + struct opt_client_fqdn req_optc; + + req_opt = IOV_PEEK_HEADER(¤t, req_optc); + if (req_opt && req_opt->flags & 0x01 /* S flag */) + o->flags = 0x02 /* O flag */; + else + o->flags = 0x00; + } opt_len++; @@ -529,12 +544,16 @@ static size_t dhcpv6_client_fqdn_fill(const struct pool *p, const struct ctx *c, int dhcpv6(struct ctx *c, const struct pool *p, const struct in6_addr *saddr, const struct in6_addr *daddr) { - const struct opt_hdr *client_id, *server_id, *ia; + const struct opt_server_id *server_id = NULL; + struct iov_tail data, opt, client_id_base; + const struct opt_hdr *client_id = NULL; + const struct opt_ia_na *ia = NULL; + struct opt_server_id server_idc; + struct opt_hdr client_idc; const struct in6_addr *src; const struct msg_hdr *mh; const struct udphdr *uh; - struct opt_hdr *bad_ia; - struct iov_tail data; + struct opt_ia_na iac; struct msg_hdr mhc; struct udphdr uhc; size_t mlen, n; @@ -563,20 +582,26 @@ int dhcpv6(struct ctx *c, const struct pool *p, src = &c->ip6.our_tap_ll; - mh = IOV_PEEK_HEADER(&data, mhc); + mh = IOV_REMOVE_HEADER(&data, mhc); if (!mh) return -1; - client_id = dhcpv6_opt(p, &(size_t){ UDP_MSG_HDR_SIZE }, OPT_CLIENTID); + client_id_base = data; + if (dhcpv6_opt(&client_id_base, OPT_CLIENTID)) + client_id = IOV_PEEK_HEADER(&client_id_base, client_idc); if (!client_id || ntohs(client_id->l) > OPT_VSIZE(client_id)) return -1; - server_id = dhcpv6_opt(p, &(size_t){ UDP_MSG_HDR_SIZE }, OPT_SERVERID); - if (server_id && ntohs(server_id->l) != OPT_VSIZE(server_id)) + opt = data; + if (dhcpv6_opt(&opt, OPT_SERVERID)) + server_id = IOV_PEEK_HEADER(&opt, server_idc); + if (server_id && ntohs(server_id->hdr.l) != OPT_VSIZE(server_id)) return -1; - ia = dhcpv6_opt(p, &(size_t){ UDP_MSG_HDR_SIZE }, OPT_IA_NA); - if (ia && ntohs(ia->l) < MIN(OPT_VSIZE(ia_na), OPT_VSIZE(ia_ta))) + opt = data; + if (dhcpv6_opt(&opt, OPT_IA_NA)) + ia = IOV_PEEK_HEADER(&opt, iac); + if (ia && ntohs(ia->hdr.l) < MIN(OPT_VSIZE(ia_na), OPT_VSIZE(ia_ta))) return -1; resp.hdr.type = TYPE_REPLY; @@ -591,9 +616,10 @@ int dhcpv6(struct ctx *c, const struct pool *p, if (mh->type == TYPE_CONFIRM && server_id) return -1; - if ((bad_ia = dhcpv6_ia_notonlink(p, &c->ip6.addr))) { + if (dhcpv6_ia_notonlink(&data, &c->ip6.addr)) { - dhcpv6_send_ia_notonlink(c, bad_ia, client_id, mh->xid); + dhcpv6_send_ia_notonlink(c, &data, &client_id_base, + ntohs(client_id->l), mh->xid); return 1; } @@ -605,7 +631,7 @@ int dhcpv6(struct ctx *c, const struct pool *p, memcmp(&resp.server_id, server_id, sizeof(resp.server_id))) return -1; - if (ia || dhcpv6_opt(p, &(size_t){ UDP_MSG_HDR_SIZE }, OPT_IA_TA)) + if (ia || dhcpv6_opt(&data, OPT_IA_TA)) return -1; info("DHCPv6: received INFORMATION_REQUEST, sending REPLY"); @@ -631,13 +657,14 @@ int dhcpv6(struct ctx *c, const struct pool *p, if (ia) resp.ia_na.iaid = ((struct opt_ia_na *)ia)->iaid; - memcpy(&resp.client_id, client_id, - ntohs(client_id->l) + sizeof(struct opt_hdr)); + iov_to_buf(&client_id_base.iov[0], client_id_base.cnt, + client_id_base.off, &resp.client_id, + ntohs(client_id->l) + sizeof(struct opt_hdr)); n = offsetof(struct resp_t, client_id) + sizeof(struct opt_hdr) + ntohs(client_id->l); n = dhcpv6_dns_fill(c, (char *)&resp, n); - n = dhcpv6_client_fqdn_fill(p, c, (char *)&resp, n); + n = dhcpv6_client_fqdn_fill(&data, c, (char *)&resp, n); resp.hdr.xid = mh->xid; diff --git a/iov.c b/iov.c index d09e51190d54..adb47293dd28 100644 --- a/iov.c +++ b/iov.c @@ -108,7 +108,6 @@ size_t iov_from_buf(const struct iovec *iov, size_t iov_cnt, * * Returns: The number of bytes successfully copied. */ -/* cppcheck-suppress [staticFunction] */ size_t iov_to_buf(const struct iovec *iov, size_t iov_cnt, size_t offset, void *buf, size_t bytes) { -- 2.49.0