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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 15:26:00 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 15:26:00 +0000
commit830407e88f9d40d954356c3754f2647f91d5c06a (patch)
treed6a0ece6feea91f3c656166dbaa884ef8a29740e /daemon/proxyv2.c
parentInitial commit. (diff)
downloadknot-resolver-830407e88f9d40d954356c3754f2647f91d5c06a.tar.xz
knot-resolver-830407e88f9d40d954356c3754f2647f91d5c06a.zip
Adding upstream version 5.6.0.upstream/5.6.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--daemon/proxyv2.c290
1 files changed, 290 insertions, 0 deletions
diff --git a/daemon/proxyv2.c b/daemon/proxyv2.c
new file mode 100644
index 0000000..f977ccb
--- /dev/null
+++ b/daemon/proxyv2.c
@@ -0,0 +1,290 @@
+/* Copyright (C) CZ.NIC, z.s.p.o. <knot-resolver@labs.nic.cz>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include "daemon/proxyv2.h"
+
+#include "lib/generic/trie.h"
+
+const char PROXY2_SIGNATURE[12] = {
+ 0x0D, 0x0A, 0x0D, 0x0A, 0x00, 0x0D, 0x0A, 0x51, 0x55, 0x49, 0x54, 0x0A
+};
+
+#define PROXY2_IP6_ADDR_SIZE 16
+#define PROXY2_UNIX_ADDR_SIZE 108
+
+#define TLV_TYPE_SSL 0x20
+
+enum proxy2_family {
+ PROXY2_AF_UNSPEC = 0x0,
+ PROXY2_AF_INET = 0x1,
+ PROXY2_AF_INET6 = 0x2,
+ PROXY2_AF_UNIX = 0x3
+};
+
+enum proxy2_protocol {
+ PROXY2_PROTOCOL_UNSPEC = 0x0,
+ PROXY2_PROTOCOL_STREAM = 0x1,
+ PROXY2_PROTOCOL_DGRAM = 0x2
+};
+
+/** PROXYv2 protocol header section */
+struct proxy2_header {
+ uint8_t signature[sizeof(PROXY2_SIGNATURE)];
+ uint8_t version_command;
+ uint8_t family_protocol;
+ uint16_t length; /**< Length of the address section */
+};
+
+/** PROXYv2 additional information in Type-Length-Value (TLV) format. */
+struct proxy2_tlv {
+ uint8_t type;
+ uint8_t length_hi;
+ uint8_t length_lo;
+ uint8_t value[];
+};
+
+/** PROXYv2 protocol address section */
+union proxy2_address {
+ struct {
+ uint32_t src_addr;
+ uint32_t dst_addr;
+ uint16_t src_port;
+ uint16_t dst_port;
+ } ipv4_addr;
+ struct {
+ uint8_t src_addr[PROXY2_IP6_ADDR_SIZE];
+ uint8_t dst_addr[PROXY2_IP6_ADDR_SIZE];
+ uint16_t src_port;
+ uint16_t dst_port;
+ } ipv6_addr;
+ struct {
+ uint8_t src_addr[PROXY2_UNIX_ADDR_SIZE];
+ uint8_t dst_addr[PROXY2_UNIX_ADDR_SIZE];
+ } unix_addr;
+};
+
+
+/** Gets protocol version from the specified PROXYv2 header. */
+static inline unsigned char proxy2_header_version(const struct proxy2_header* h)
+{
+ return (h->version_command & 0xF0) >> 4;
+}
+
+/** Gets command from the specified PROXYv2 header. */
+static inline enum proxy2_command proxy2_header_command(const struct proxy2_header *h)
+{
+ return h->version_command & 0x0F;
+}
+
+/** Gets address family from the specified PROXYv2 header. */
+static inline enum proxy2_family proxy2_header_family(const struct proxy2_header *h)
+{
+ return (h->family_protocol & 0xF0) >> 4;
+}
+
+/** Gets transport protocol from the specified PROXYv2 header. */
+static inline enum proxy2_family proxy2_header_protocol(const struct proxy2_header *h)
+{
+ return h->family_protocol & 0x0F;
+}
+
+static inline union proxy2_address *proxy2_get_address(const struct proxy2_header *h)
+{
+ return (union proxy2_address *) ((uint8_t *) h + sizeof(struct proxy2_header));
+}
+
+static inline struct proxy2_tlv *get_tlvs(const struct proxy2_header *h, size_t addr_len)
+{
+ return (struct proxy2_tlv *) ((uint8_t *) proxy2_get_address(h) + addr_len);
+}
+
+/** Gets the length of the TLV's `value` attribute. */
+static inline uint16_t proxy2_tlv_length(const struct proxy2_tlv *tlv)
+{
+ return ((uint16_t) tlv->length_hi << 16) | tlv->length_lo;
+}
+
+static inline bool has_tlv(const struct proxy2_header *h,
+ const struct proxy2_tlv *tlv)
+{
+ uint64_t addr_length = ntohs(h->length);
+ ptrdiff_t hdr_len = sizeof(struct proxy2_header) + addr_length;
+
+ uint8_t *tlv_hdr_end = (uint8_t *) tlv + sizeof(struct proxy2_tlv);
+ ptrdiff_t distance = tlv_hdr_end - (uint8_t *) h;
+ if (hdr_len < distance)
+ return false;
+
+ uint8_t *tlv_end = tlv_hdr_end + proxy2_tlv_length(tlv);
+ distance = tlv_end - (uint8_t *) h;
+ return hdr_len >= distance;
+}
+
+static inline void next_tlv(struct proxy2_tlv **tlv)
+{
+ uint8_t *next = ((uint8_t *) *tlv + sizeof(struct proxy2_tlv) + proxy2_tlv_length(*tlv));
+ *tlv = (struct proxy2_tlv *) next;
+}
+
+
+bool proxy_allowed(const struct network *net, const struct sockaddr *saddr)
+{
+ union kr_in_addr addr;
+ trie_t *trie;
+ size_t addr_size;
+ switch (saddr->sa_family) {
+ case AF_INET:
+ if (net->proxy_all4)
+ return true;
+
+ trie = net->proxy_addrs4;
+ addr_size = sizeof(addr.ip4);
+ addr.ip4 = ((struct sockaddr_in *) saddr)->sin_addr;
+ break;
+ case AF_INET6:
+ if (net->proxy_all6)
+ return true;
+
+ trie = net->proxy_addrs6;
+ addr_size = sizeof(addr.ip6);
+ addr.ip6 = ((struct sockaddr_in6 *) saddr)->sin6_addr;
+ break;
+ default:
+ kr_assert(false); // Only IPv4 and IPv6 proxy addresses supported
+ return false;
+ }
+
+ trie_val_t *val;
+ int ret = trie_get_leq(trie, (char *) &addr, addr_size, &val);
+ if (ret != kr_ok() && ret != 1)
+ return false;
+
+ kr_assert(val);
+ const struct net_proxy_data *found = *val;
+ kr_assert(found);
+ return kr_bitcmp((char *) &addr, (char *) &found->addr, found->netmask) == 0;
+}
+
+ssize_t proxy_process_header(struct proxy_result *out, struct session *s,
+ const void *buf, const ssize_t nread)
+{
+ if (!buf)
+ return kr_error(EINVAL);
+
+ const struct proxy2_header *hdr = (struct proxy2_header *) buf;
+
+ uint64_t content_length = ntohs(hdr->length);
+ ssize_t hdr_len = sizeof(struct proxy2_header) + content_length;
+
+ /* PROXYv2 requires the header to be received all at once */
+ if (nread < hdr_len) {
+ return kr_error(KNOT_EMALF);
+ }
+
+ unsigned char version = proxy2_header_version(hdr);
+ if (version != 2) {
+ /* Version MUST be 2 for PROXYv2 protocol */
+ return kr_error(KNOT_EMALF);
+ }
+
+ enum proxy2_command command = proxy2_header_command(hdr);
+ if (command == PROXY2_CMD_LOCAL) {
+ /* Addresses for LOCAL are to be discarded */
+ *out = (struct proxy_result) { .command = PROXY2_CMD_LOCAL };
+ goto fill_wirebuf;
+ }
+
+ if (command != PROXY2_CMD_PROXY) {
+ /* PROXYv2 prohibits values other than LOCAL and PROXY */
+ return kr_error(KNOT_EMALF);
+ }
+
+ *out = (struct proxy_result) { .command = PROXY2_CMD_PROXY };
+
+ /* Parse flags */
+ enum proxy2_family family = proxy2_header_family(hdr);
+ switch(family) {
+ case PROXY2_AF_UNSPEC:
+ case PROXY2_AF_UNIX: /* UNIX is unsupported, fall back to UNSPEC */
+ out->family = AF_UNSPEC;
+ break;
+ case PROXY2_AF_INET:
+ out->family = AF_INET;
+ break;
+ case PROXY2_AF_INET6:
+ out->family = AF_INET6;
+ break;
+ default: /* PROXYv2 prohibits other values */
+ return kr_error(KNOT_EMALF);
+ }
+
+ enum proxy2_family protocol = proxy2_header_protocol(hdr);
+ switch (protocol) {
+ case PROXY2_PROTOCOL_DGRAM:
+ out->protocol = SOCK_DGRAM;
+ break;
+ case PROXY2_PROTOCOL_STREAM:
+ out->protocol = SOCK_STREAM;
+ break;
+ default: /* PROXYv2 prohibits other values */
+ return kr_error(KNOT_EMALF);
+ }
+
+ /* Parse addresses */
+ union proxy2_address* addr = proxy2_get_address(hdr);
+ size_t addr_length = 0;
+ switch(out->family) {
+ case AF_INET:
+ addr_length = sizeof(addr->ipv4_addr);
+ if (content_length < addr_length)
+ return kr_error(KNOT_EMALF);
+
+ out->src_addr.ip4 = (struct sockaddr_in) {
+ .sin_family = AF_INET,
+ .sin_addr = { .s_addr = addr->ipv4_addr.src_addr },
+ .sin_port = addr->ipv4_addr.src_port,
+ };
+ out->dst_addr.ip4 = (struct sockaddr_in) {
+ .sin_family = AF_INET,
+ .sin_addr = { .s_addr = addr->ipv4_addr.dst_addr },
+ .sin_port = addr->ipv4_addr.dst_port,
+ };
+ break;
+ case AF_INET6:
+ addr_length = sizeof(addr->ipv6_addr);
+ if (content_length < addr_length)
+ return kr_error(KNOT_EMALF);
+
+ out->src_addr.ip6 = (struct sockaddr_in6) {
+ .sin6_family = AF_INET6,
+ .sin6_port = addr->ipv6_addr.src_port
+ };
+ memcpy(
+ &out->src_addr.ip6.sin6_addr.s6_addr,
+ &addr->ipv6_addr.src_addr,
+ sizeof(out->src_addr.ip6.sin6_addr.s6_addr));
+ out->dst_addr.ip6 = (struct sockaddr_in6) {
+ .sin6_family = AF_INET6,
+ .sin6_port = addr->ipv6_addr.dst_port
+ };
+ memcpy(
+ &out->dst_addr.ip6.sin6_addr.s6_addr,
+ &addr->ipv6_addr.dst_addr,
+ sizeof(out->dst_addr.ip6.sin6_addr.s6_addr));
+ break;
+ }
+
+ /* Process additional information */
+ for (struct proxy2_tlv *tlv = get_tlvs(hdr, addr_length); has_tlv(hdr, tlv); next_tlv(&tlv)) {
+ switch (tlv->type) {
+ case TLV_TYPE_SSL:
+ out->has_tls = true;
+ break;
+ /* TODO: add more TLV types if needed */
+ }
+ }
+
+fill_wirebuf:
+ return session_wirebuf_trim(s, hdr_len);
+}