diff options
Diffstat (limited to 'fwd.c')
| -rw-r--r-- | fwd.c | 103 |
1 files changed, 103 insertions, 0 deletions
@@ -13,6 +13,7 @@ * Author: David Gibson <david@gibson.dropbear.id.au> */ +#include <assert.h> #include <stdint.h> #include <errno.h> #include <fcntl.h> @@ -22,6 +23,8 @@ #include "util.h" #include "ip.h" +#include "siphash.h" +#include "inany.h" #include "fwd.h" #include "passt.h" #include "lineread.h" @@ -301,6 +304,20 @@ parse_err: } /** + * fwd_rule_addr() - Return match address for a rule + * @rule: Forwarding rule + * + * Return: matching address for rule, NULL if it matches all addresses + */ +static const union inany_addr *fwd_rule_addr(const struct fwd_rule *rule) +{ + if (rule->flags & FWD_DUAL_STACK_ANY) + return NULL; + + return &rule->addr; +} + +/** * fwd_port_is_ephemeral() - Is port number ephemeral? * @port: Port number * @@ -313,6 +330,92 @@ bool fwd_port_is_ephemeral(in_port_t port) return (port >= fwd_ephemeral_min) && (port <= fwd_ephemeral_max); } +/** + * fwd_rule_add() - Add a rule to a forwarding table + * @fwd: Table to add to + * @flags: Flags for this entry + * @addr: Our address to forward (NULL for both 0.0.0.0 and ::) + * @ifname: Only forward from this interface name, if non-empty + * @first: First port number to forward + * @last: Last port number to forward + * @to: First port of target port range to map to + */ +void fwd_rule_add(struct fwd_ports *fwd, uint8_t flags, + const union inany_addr *addr, const char *ifname, + in_port_t first, in_port_t last, in_port_t to) +{ + /* Flags which can be set from the caller */ + const uint8_t allowed_flags = FWD_WEAK; + struct fwd_rule *new; + unsigned port; + + ASSERT(!(flags & ~allowed_flags)); + + if (fwd->count >= ARRAY_SIZE(fwd->rules)) + die("Too many port forwarding ranges"); + + new = &fwd->rules[fwd->count++]; + new->flags = flags; + + if (addr) { + new->addr = *addr; + } else { + new->addr = inany_any6; + new->flags |= FWD_DUAL_STACK_ANY; + } + + memset(new->ifname, 0, sizeof(new->ifname)); + if (ifname) { + int ret; + + ret = snprintf(new->ifname, sizeof(new->ifname), "%s", ifname); + if (ret <= 0 || (size_t)ret >= sizeof(new->ifname)) + die("Invalid interface name: %s", ifname); + } + + ASSERT(first <= last); + new->first = first; + new->last = last; + + new->to = to; + + for (port = new->first; port <= new->last; port++) { + /* Fill in the legacy data structures to match the table */ + bitmap_set(fwd->map, port); + fwd->delta[port] = new->to - new->first; + } +} + +/** + * fwd_rules_print() - Print forwarding rules for debugging + * @fwd: Table to print + */ +void fwd_rules_print(const struct fwd_ports *fwd) +{ + unsigned i; + + for (i = 0; i < fwd->count; i++) { + const struct fwd_rule *rule = &fwd->rules[i]; + const char *percent = *rule->ifname ? "%" : ""; + char addr[INANY_ADDRSTRLEN]; + const char *weak = ""; + + inany_ntop(fwd_rule_addr(rule), addr, sizeof(addr)); + if (rule->flags & FWD_WEAK) + weak = " (best effort)"; + + if (rule->first == rule->last) { + info(" [%s]%s%s:%hu => %hu %s", + addr, percent, rule->ifname, + rule->first, rule->to, weak); + } else { + info(" [%s]%s%s:%hu-%hu => %hu-%hu %s", + addr, percent, rule->ifname, rule->first, rule->last, + rule->to, rule->last - rule->first + rule->to, weak); + } + } +} + /* See enum in kernel's include/net/tcp_states.h */ #define UDP_LISTEN 0x07 #define TCP_LISTEN 0x0a |