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060f24e310
Currently the code to translate host side addresses and ports to guest side addresses and ports, and vice versa, is scattered across the TCP code. This includes both port redirection as controlled by the -t and -T options, and our special case NAT controlled by the --no-map-gw option. Gather this logic into fwd_nat_from_*() functions for each input interface in fwd.c which take protocol and address information for the initiating side and generates the pif and address information for the forwarded side. This performs any NAT or port forwarding needed. We create a flow_target() helper which applies those forwarding functions as needed to automatically move a flow from INI to TGT state. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
152 lines
4.1 KiB
C
152 lines
4.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later
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* Copyright Red Hat
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* Author: David Gibson <david@gibson.dropbear.id.au>
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*
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* Definitions for the global table of packet flows.
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*/
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#ifndef FLOW_TABLE_H
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#define FLOW_TABLE_H
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#include "tcp_conn.h"
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#include "icmp_flow.h"
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/**
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* struct flow_free_cluster - Information about a cluster of free entries
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* @f: Generic flow information
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* @n: Number of entries in the free cluster (including this one)
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* @next: Index of next free cluster
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*/
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struct flow_free_cluster {
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/* Must be first element */
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struct flow_common f;
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unsigned n;
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unsigned next;
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};
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/**
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* union flow - Descriptor for a logical packet flow (e.g. connection)
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* @f: Fields common between all variants
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* @tcp: Fields for non-spliced TCP connections
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* @tcp_splice: Fields for spliced TCP connections
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*/
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union flow {
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struct flow_common f;
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struct flow_free_cluster free;
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struct tcp_tap_conn tcp;
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struct tcp_splice_conn tcp_splice;
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struct icmp_ping_flow ping;
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};
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/* Global Flow Table */
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extern unsigned flow_first_free;
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extern union flow flowtab[];
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/**
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* flow_foreach_sidei() - 'for' type macro to step through each side of flow
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* @sidei_: Takes value INISIDE, then TGTSIDE
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*/
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#define flow_foreach_sidei(sidei_) \
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for ((sidei_) = INISIDE; (sidei_) < SIDES; (sidei_)++)
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/** flow_idx() - Index of flow from common structure
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* @f: Common flow fields pointer
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*
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* Return: index of @f in the flow table
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*/
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static inline unsigned flow_idx(const struct flow_common *f)
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{
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return (union flow *)f - flowtab;
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}
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/** FLOW_IDX() - Find the index of a flow
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* @f_: Flow pointer, either union flow * or protocol specific
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*
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* Return: index of @f in the flow table
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*/
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#define FLOW_IDX(f_) (flow_idx(&(f_)->f))
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/** FLOW() - Flow entry at a given index
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* @idx: Flow index
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*
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* Return: pointer to entry @idx in the flow table
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*/
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#define FLOW(idx) (&flowtab[(idx)])
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/** flow_at_sidx() - Flow entry for a given sidx
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* @sidx: Flow & side index
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*
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* Return: pointer to the corresponding flow entry, or NULL
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*/
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static inline union flow *flow_at_sidx(flow_sidx_t sidx)
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{
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if (!flow_sidx_valid(sidx))
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return NULL;
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return FLOW(sidx.flowi);
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}
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/** pif_at_sidx() - Interface for a given flow and side
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* @sidx: Flow & side index
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*
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* Return: pif for the flow & side given by @sidx
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*/
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static inline uint8_t pif_at_sidx(flow_sidx_t sidx)
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{
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const union flow *flow = flow_at_sidx(sidx);
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if (!flow)
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return PIF_NONE;
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return flow->f.pif[sidx.sidei];
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}
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/** flow_sidx() - Index of one side of a flow from common structure
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* @f: Common flow fields pointer
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* @sidei: Which side to refer to (0 or 1)
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*
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* Return: index of @f and @side in the flow table
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*/
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static inline flow_sidx_t flow_sidx(const struct flow_common *f,
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unsigned sidei)
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{
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/* cppcheck-suppress [knownConditionTrueFalse, unmatchedSuppression] */
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ASSERT(sidei == !!sidei);
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return (flow_sidx_t){
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.sidei = sidei,
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.flowi = flow_idx(f),
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};
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}
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/** FLOW_SIDX() - Find the index of one side of a flow
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* @f_: Flow pointer, either union flow * or protocol specific
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* @sidei: Which side to index (0 or 1)
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*
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* Return: index of @f and @side in the flow table
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*/
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#define FLOW_SIDX(f_, sidei) (flow_sidx(&(f_)->f, (sidei)))
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union flow *flow_alloc(void);
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void flow_alloc_cancel(union flow *flow);
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const struct flowside *flow_initiate_af(union flow *flow, uint8_t pif,
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sa_family_t af,
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const void *saddr, in_port_t sport,
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const void *daddr, in_port_t dport);
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const struct flowside *flow_initiate_sa(union flow *flow, uint8_t pif,
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const union sockaddr_inany *ssa,
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in_port_t dport);
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const struct flowside *flow_target_af(union flow *flow, uint8_t pif,
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sa_family_t af,
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const void *saddr, in_port_t sport,
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const void *daddr, in_port_t dport);
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const struct flowside *flow_target(const struct ctx *c, union flow *flow,
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uint8_t proto);
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union flow *flow_set_type(union flow *flow, enum flow_type type);
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#define FLOW_SET_TYPE(flow_, t_, var_) (&flow_set_type((flow_), (t_))->var_)
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void flow_activate(struct flow_common *f);
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#define FLOW_ACTIVATE(flow_) \
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(flow_activate(&(flow_)->f))
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#endif /* FLOW_TABLE_H */
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