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-rw-r--r--src/qmqpd/qmqpd_peer.c309
1 files changed, 309 insertions, 0 deletions
diff --git a/src/qmqpd/qmqpd_peer.c b/src/qmqpd/qmqpd_peer.c
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+++ b/src/qmqpd/qmqpd_peer.c
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+/*++
+/* NAME
+/* qmqpd_peer 3
+/* SUMMARY
+/* look up peer name/address information
+/* SYNOPSIS
+/* #include "qmqpd.h"
+/*
+/* void qmqpd_peer_init(state)
+/* QMQPD_STATE *state;
+/*
+/* void qmqpd_peer_reset(state)
+/* QMQPD_STATE *state;
+/* DESCRIPTION
+/* The qmqpd_peer_init() routine attempts to produce a printable
+/* version of the peer name and address of the specified socket.
+/* Where information is unavailable, the name and/or address
+/* are set to "unknown".
+/*
+/* qmqpd_peer_init() updates the following fields:
+/* .IP name
+/* The client hostname. An unknown name is represented by the
+/* string "unknown".
+/* .IP addr
+/* Printable representation of the client address.
+/* .IP namaddr
+/* String of the form: "name[addr]:port".
+/* .PP
+/* qmqpd_peer_reset() releases memory allocated by qmqpd_peer_init().
+/* LICENSE
+/* .ad
+/* .fi
+/* The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/* Wietse Venema
+/* IBM T.J. Watson Research
+/* P.O. Box 704
+/* Yorktown Heights, NY 10598, USA
+/*
+/* Wietse Venema
+/* Google, Inc.
+/* 111 8th Avenue
+/* New York, NY 10011, USA
+/*--*/
+
+/* System library. */
+
+#include <sys_defs.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <errno.h>
+#include <netdb.h>
+#include <string.h>
+
+/* Utility library. */
+
+#include <msg.h>
+#include <mymalloc.h>
+#include <stringops.h>
+#include <myaddrinfo.h>
+#include <sock_addr.h>
+#include <inet_proto.h>
+#include <split_at.h>
+
+/* Global library. */
+
+#include <mail_proto.h>
+#include <valid_mailhost_addr.h>
+#include <mail_params.h>
+
+/* Application-specific. */
+
+#include "qmqpd.h"
+
+/* qmqpd_peer_init - initialize peer information */
+
+void qmqpd_peer_init(QMQPD_STATE *state)
+{
+ const char *myname = "qmqpd_peer_init";
+ struct sockaddr_storage ss;
+ struct sockaddr *sa;
+ SOCKADDR_SIZE sa_length;
+ const INET_PROTO_INFO *proto_info = inet_proto_info();
+
+ sa = (struct sockaddr *) &ss;
+ sa_length = sizeof(ss);
+
+ /*
+ * Look up the peer address information.
+ */
+ if (getpeername(vstream_fileno(state->client), sa, &sa_length) >= 0) {
+ errno = 0;
+ }
+
+ /*
+ * If peer went away, give up.
+ */
+ if (errno != 0 && errno != ENOTSOCK) {
+ state->name = mystrdup(CLIENT_NAME_UNKNOWN);
+ state->addr = mystrdup(CLIENT_ADDR_UNKNOWN);
+ state->rfc_addr = mystrdup(CLIENT_ADDR_UNKNOWN);
+ state->addr_family = AF_UNSPEC;
+ state->port = mystrdup(CLIENT_PORT_UNKNOWN);
+ }
+
+ /*
+ * Convert the client address to printable address and hostname.
+ *
+ * XXX If we're given an IPv6 (or IPv4) connection from, e.g., inetd, while
+ * Postfix IPv6 (or IPv4) support is turned off, don't (skip to the final
+ * else clause, pretend the origin is localhost[127.0.0.1], and become an
+ * open relay).
+ */
+ else if (errno == 0
+ && (sa->sa_family == AF_INET
+#ifdef AF_INET6
+ || sa->sa_family == AF_INET6
+#endif
+ )) {
+ MAI_HOSTNAME_STR client_name;
+ MAI_HOSTADDR_STR client_addr;
+ MAI_SERVPORT_STR client_port;
+ int aierr;
+ char *colonp;
+
+ /*
+ * Sanity check: we can't use sockets that we're not configured for.
+ */
+ if (strchr((char *) proto_info->sa_family_list, sa->sa_family) == 0)
+ msg_fatal("cannot handle socket type %s with \"%s = %s\"",
+#ifdef AF_INET6
+ sa->sa_family == AF_INET6 ? "AF_INET6" :
+#endif
+ sa->sa_family == AF_INET ? "AF_INET" :
+ "other", VAR_INET_PROTOCOLS, var_inet_protocols);
+
+ /*
+ * Sorry, but there are some things that we just cannot do while
+ * connected to the network.
+ */
+ if (geteuid() != var_owner_uid || getuid() != var_owner_uid) {
+ msg_error("incorrect QMQP server privileges: uid=%lu euid=%lu",
+ (unsigned long) getuid(), (unsigned long) geteuid());
+ msg_fatal("the Postfix QMQP server must run with $%s privileges",
+ VAR_MAIL_OWNER);
+ }
+
+ /*
+ * Convert the client address to printable form.
+ */
+ if ((aierr = sockaddr_to_hostaddr(sa, sa_length, &client_addr,
+ &client_port, 0)) != 0)
+ msg_fatal("%s: cannot convert client address/port to string: %s",
+ myname, MAI_STRERROR(aierr));
+ state->port = mystrdup(client_port.buf);
+
+ /*
+ * XXX Require that the infrastructure strips off the IPv6 datalink
+ * suffix to avoid false alarms with strict address syntax checks.
+ */
+#ifdef HAS_IPV6
+ if (strchr(client_addr.buf, '%') != 0)
+ msg_panic("%s: address %s has datalink suffix",
+ myname, client_addr.buf);
+#endif
+
+ /*
+ * We convert IPv4-in-IPv6 address to 'true' IPv4 address early on,
+ * but only if IPv4 support is enabled (why would anyone want to turn
+ * it off)? With IPv4 support enabled we have no need for the IPv6
+ * form in logging, hostname verification and access checks.
+ */
+#ifdef HAS_IPV6
+ if (sa->sa_family == AF_INET6) {
+ if (strchr((char *) proto_info->sa_family_list, AF_INET) != 0
+ && IN6_IS_ADDR_V4MAPPED(&SOCK_ADDR_IN6_ADDR(sa))
+ && (colonp = strrchr(client_addr.buf, ':')) != 0) {
+ struct addrinfo *res0;
+
+ if (msg_verbose > 1)
+ msg_info("%s: rewriting V4-mapped address \"%s\" to \"%s\"",
+ myname, client_addr.buf, colonp + 1);
+
+ state->addr = mystrdup(colonp + 1);
+ state->rfc_addr = mystrdup(colonp + 1);
+ state->addr_family = AF_INET;
+ aierr = hostaddr_to_sockaddr(state->addr, (char *) 0, 0, &res0);
+ if (aierr)
+ msg_fatal("%s: cannot convert %s from string to binary: %s",
+ myname, state->addr, MAI_STRERROR(aierr));
+ sa_length = res0->ai_addrlen;
+ if (sa_length > sizeof(ss))
+ sa_length = sizeof(ss);
+ memcpy((void *) sa, res0->ai_addr, sa_length);
+ freeaddrinfo(res0);
+ }
+
+ /*
+ * Following RFC 2821 section 4.1.3, an IPv6 address literal gets
+ * a prefix of 'IPv6:'. We do this consistently for all IPv6
+ * addresses that appear in headers or envelopes. The fact
+ * that valid_mailhost_addr() enforces the form helps of course.
+ * We use the form without IPV6: prefix when doing access
+ * control, or when accessing the connection cache.
+ */
+ else {
+ state->addr = mystrdup(client_addr.buf);
+ state->rfc_addr =
+ concatenate(IPV6_COL, client_addr.buf, (char *) 0);
+ state->addr_family = sa->sa_family;
+ }
+ }
+
+ /*
+ * An IPv4 address is in dotted quad decimal form.
+ */
+ else
+#endif
+ {
+ state->addr = mystrdup(client_addr.buf);
+ state->rfc_addr = mystrdup(client_addr.buf);
+ state->addr_family = sa->sa_family;
+ }
+
+ /*
+ * Look up and sanity check the client hostname.
+ *
+ * It is unsafe to allow numeric hostnames, especially because there
+ * exists pressure to turn off the name->addr double check. In that
+ * case an attacker could trivally bypass access restrictions.
+ *
+ * sockaddr_to_hostname() already rejects malformed or numeric names.
+ */
+#define REJECT_PEER_NAME(state) { \
+ myfree(state->name); \
+ state->name = mystrdup(CLIENT_NAME_UNKNOWN); \
+ }
+
+ if ((aierr = sockaddr_to_hostname(sa, sa_length, &client_name,
+ (MAI_SERVNAME_STR *) 0, 0)) != 0) {
+ state->name = mystrdup(CLIENT_NAME_UNKNOWN);
+ } else {
+ struct addrinfo *res0;
+ struct addrinfo *res;
+
+ state->name = mystrdup(client_name.buf);
+
+ /*
+ * Reject the hostname if it does not list the peer address.
+ */
+ aierr = hostname_to_sockaddr_pf(state->name, state->addr_family,
+ (char *) 0, 0, &res0);
+ if (aierr) {
+ msg_warn("hostname %s does not resolve to address %s: %s",
+ state->name, state->addr, MAI_STRERROR(aierr));
+ REJECT_PEER_NAME(state);
+ } else {
+ for (res = res0; /* void */ ; res = res->ai_next) {
+ if (res == 0) {
+ msg_warn("hostname %s does not resolve to address %s",
+ state->addr, state->name);
+ REJECT_PEER_NAME(state);
+ break;
+ }
+ if (strchr((char *) proto_info->sa_family_list, res->ai_family) == 0) {
+ msg_info("skipping address family %d for host %s",
+ res->ai_family, state->name);
+ continue;
+ }
+ if (sock_addr_cmp_addr(res->ai_addr, sa) == 0)
+ break; /* keep peer name */
+ }
+ freeaddrinfo(res0);
+ }
+ }
+ }
+
+ /*
+ * If it's not Internet, assume the client is local, and avoid using the
+ * naming service because that can hang when the machine is disconnected.
+ */
+ else {
+ state->name = mystrdup("localhost");
+ state->addr = mystrdup("127.0.0.1"); /* XXX bogus. */
+ state->rfc_addr = mystrdup("127.0.0.1");/* XXX bogus. */
+ state->addr_family = AF_UNSPEC;
+ state->port = mystrdup("0"); /* XXX bogus. */
+ }
+
+ /*
+ * Do the name[addr]:port formatting for pretty reports.
+ */
+ state->namaddr =
+ concatenate(state->name, "[", state->addr, "]",
+ var_qmqpd_client_port_log ? ":" : (char *) 0,
+ state->port, (char *) 0);
+}
+
+/* qmqpd_peer_reset - destroy peer information */
+
+void qmqpd_peer_reset(QMQPD_STATE *state)
+{
+ myfree(state->name);
+ myfree(state->addr);
+ myfree(state->namaddr);
+ myfree(state->rfc_addr);
+ myfree(state->port);
+}
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