summaryrefslogtreecommitdiffstats
path: root/src/smtp/smtp_key.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--src/smtp/smtp_key.c215
1 files changed, 215 insertions, 0 deletions
diff --git a/src/smtp/smtp_key.c b/src/smtp/smtp_key.c
new file mode 100644
index 0000000..643f4db
--- /dev/null
+++ b/src/smtp/smtp_key.c
@@ -0,0 +1,215 @@
+/*++
+/* NAME
+/* smtp_key 3
+/* SUMMARY
+/* cache/table lookup key management
+/* SYNOPSIS
+/* #include "smtp.h"
+/*
+/* char *smtp_key_prefix(buffer, delim_na, iterator, context_flags)
+/* VSTRING *buffer;
+/* const char *delim_na;
+/* SMTP_ITERATOR *iterator;
+/* int context_flags;
+/* DESCRIPTION
+/* The Postfix SMTP server accesses caches and lookup tables,
+/* using lookup keys that contain information from various
+/* contexts: per-server configuration, per-request envelope,
+/* and results from DNS queries.
+/*
+/* These lookup keys sometimes share the same context information.
+/* The primary purpose of this API is to ensure that this
+/* shared context is used consistently, and that its use is
+/* made explicit (both are needed to verify that there is no
+/* false cache sharing).
+/*
+/* smtp_key_prefix() constructs a lookup key prefix from context
+/* that may be shared with other lookup keys. The user is free
+/* to append additional application-specific context. The result
+/* value is a pointer to the result text.
+/*
+/* Arguments:
+/* .IP buffer
+/* Storage for the result.
+/* .IP delim_na
+/* The field delimiter character, and the optional place holder
+/* character for a) information that is unavailable, b)
+/* information that is inapplicable, or c) that would result
+/* in an empty field. Key fields that contain "delim_na"
+/* characters will be base64-encoded.
+/* Do not specify "delim_na" characters that are part of the
+/* base64 character set.
+/* .IP iterator
+/* Information that will be selected by the specified flags.
+/* .IP context_flags
+/* Bit-wise OR of one or more of the following.
+/* .RS
+/* .IP SMTP_KEY_FLAG_SERVICE
+/* The global service name. This is a proxy for
+/* destination-independent and request-independent context.
+/* .IP SMTP_KEY_FLAG_SENDER
+/* The envelope sender address. This is a proxy for sender-dependent
+/* context, such as per-sender SASL authentication.
+/* .IP SMTP_KEY_FLAG_REQ_NEXTHOP
+/* The delivery request nexthop destination, including optional
+/* [] and :port (the same form that users specify in a SASL
+/* password or TLS policy lookup table). This is a proxy for
+/* destination-dependent, but host-independent context.
+/* .IP SMTP_KEY_FLAG_CUR_NEXTHOP
+/* The current iterator's nexthop destination (delivery request
+/* nexthop or fallback nexthop, including optional [] and
+/* :port).
+/* .IP SMTP_KEY_FLAG_HOSTNAME
+/* The current iterator's remote hostname.
+/* .IP SMTP_KEY_FLAG_ADDR
+/* The current iterator's remote address.
+/* .IP SMTP_KEY_FLAG_PORT
+/* The current iterator's remote port.
+/* .RE
+/* DIAGNOSTICS
+/* Panic: undefined flag or zero flags. Fatal: out of memory.
+/* 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 <netinet/in.h> /* ntohs() for Solaris or BSD */
+#include <arpa/inet.h> /* ntohs() for Linux or BSD */
+#include <string.h>
+
+ /*
+ * Utility library.
+ */
+#include <msg.h>
+#include <vstring.h>
+#include <base64_code.h>
+
+ /*
+ * Global library.
+ */
+#include <mail_params.h>
+
+ /*
+ * Application-specific.
+ */
+#include <smtp.h>
+
+ /*
+ * We use a configurable field terminator and optional place holder for data
+ * that is unavailable or inapplicable. We base64-encode content that
+ * contains these characters, and content that needs obfuscation.
+ */
+
+/* smtp_key_append_na - append place-holder key field */
+
+static void smtp_key_append_na(VSTRING *buffer, const char *delim_na)
+{
+ if (delim_na[1] != 0)
+ VSTRING_ADDCH(buffer, delim_na[1]);
+ VSTRING_ADDCH(buffer, delim_na[0]);
+}
+
+/* smtp_key_append_str - append string-valued key field */
+
+static void smtp_key_append_str(VSTRING *buffer, const char *str,
+ const char *delim_na)
+{
+ if (str == 0 || str[0] == 0) {
+ smtp_key_append_na(buffer, delim_na);
+ } else if (str[strcspn(str, delim_na)] != 0) {
+ base64_encode_opt(buffer, str, strlen(str), BASE64_FLAG_APPEND);
+ VSTRING_ADDCH(buffer, delim_na[0]);
+ } else {
+ vstring_sprintf_append(buffer, "%s%c", str, delim_na[0]);
+ }
+}
+
+/* smtp_key_append_uint - append unsigned-valued key field */
+
+static void smtp_key_append_uint(VSTRING *buffer, unsigned num,
+ const char *delim_na)
+{
+ vstring_sprintf_append(buffer, "%u%c", num, delim_na[0]);
+}
+
+/* smtp_key_prefix - format common elements in lookup key */
+
+char *smtp_key_prefix(VSTRING *buffer, const char *delim_na,
+ SMTP_ITERATOR *iter, int flags)
+{
+ static const char myname[] = "smtp_key_prefix";
+ SMTP_STATE *state = iter->parent; /* private member */
+
+ /*
+ * Sanity checks.
+ */
+ if (state == 0)
+ msg_panic("%s: no parent state", myname);
+ if (flags & ~SMTP_KEY_MASK_ALL)
+ msg_panic("%s: unknown key flags 0x%x",
+ myname, flags & ~SMTP_KEY_MASK_ALL);
+ if (flags == 0)
+ msg_panic("%s: zero flags", myname);
+
+ /*
+ * Initialize.
+ */
+ VSTRING_RESET(buffer);
+
+ /*
+ * Per-service and per-request context.
+ */
+ if (flags & SMTP_KEY_FLAG_SERVICE)
+ smtp_key_append_str(buffer, state->service, delim_na);
+ if (flags & SMTP_KEY_FLAG_SENDER)
+ smtp_key_append_str(buffer, state->request->sender, delim_na);
+
+ /*
+ * Per-destination context, non-canonicalized form.
+ */
+ if (flags & SMTP_KEY_FLAG_REQ_NEXTHOP)
+ smtp_key_append_str(buffer, STR(iter->request_nexthop), delim_na);
+ if (flags & SMTP_KEY_FLAG_CUR_NEXTHOP)
+ smtp_key_append_str(buffer, STR(iter->dest), delim_na);
+
+ /*
+ * Per-host context, canonicalized form.
+ */
+ if (flags & SMTP_KEY_FLAG_HOSTNAME)
+ smtp_key_append_str(buffer, STR(iter->host), delim_na);
+ if (flags & SMTP_KEY_FLAG_ADDR)
+ smtp_key_append_str(buffer, STR(iter->addr), delim_na);
+ if (flags & SMTP_KEY_FLAG_PORT)
+ smtp_key_append_uint(buffer, ntohs(iter->port), delim_na);
+
+ /*
+ * Requested TLS level, if applicable. TODO(tlsproxy) should the lookup
+ * engine also try the requested TLS level and 'stronger', in case a
+ * server hosts multiple domains with different TLS requirements?
+ */
+ if (flags & SMTP_KEY_FLAG_TLS_LEVEL)
+#ifdef USE_TLS
+ smtp_key_append_uint(buffer, state->tls->level, delim_na);
+#else
+ smtp_key_append_na(buffer, delim_na);
+#endif
+
+ VSTRING_TERMINATE(buffer);
+
+ return STR(buffer);
+}