iscsi-login.c

iSCSI协议在LINUX下的源码.源代码是IBM公布的.主要是结合其OSD设备用的.

/*
 * iSCSI login library
 * Copyright (C) 2001 Cisco Systems, Inc.
 * maintained by [e-mail]
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * See the file COPYING included with this distribution for more details.
 *
 * $Id: iscsi-login.c,v 1.33 2005/01/19 22:55:30 mikenc Exp $
 *
 *
 * Formation of iSCSI login pdu, processing the login response and other
 * functions are defined here
 */
#include "iscsi-session.h"
#include "iscsi-login.h"
#include "iscsi-protocol.h"
#include "iscsi-sfnet.h"

/* caller is assumed to be well-behaved and passing NUL terminated strings */
int
iscsi_add_text(struct iscsi_session *session, struct iscsi_hdr *pdu, char *data,
	       int max_data_length, char *param, char *value)
{
	int param_len = strlen(param);
	int value_len = strlen(value);
	int length = param_len + 1 + value_len + 1;	/* param, separator,
							 * value, and trailing
							 * NULL
							 */
	int pdu_length = ntoh24(pdu->dlength);
	char *text = data;
	char *end = data + max_data_length;
	char *pdu_text;

	/* find the end of the current text */
	text += pdu_length;
	pdu_text = text;
	pdu_length += length;

	if (text + length >= end) {
		iscsi_host_notice(session, "Failed to add login text "
				  "'%s=%s'\n", param, value);
		return 0;
	}

	/* param */
	strncpy(text, param, param_len);
	text += param_len;

	/* separator */
	*text++ = ISCSI_TEXT_SEPARATOR;

	/* value */
	strncpy(text, value, value_len);
	text += value_len;

	/* NUL */
	*text++ = '\0';

	/* update the length in the PDU header */
	hton24(pdu->dlength, pdu_length);

	return 1;
}

static int
iscsi_find_key_value(char *param, char *pdu, char *pdu_end, char **value_start,
		     char **value_end)
{
	char *str = param;
	char *text = pdu;
	char *value;

	if (value_start)
		*value_start = NULL;
	if (value_end)
		*value_end = NULL;

	/* make sure they contain the same bytes */
	while (*str) {
		if (text >= pdu_end)
			return 0;
		if (*text == '\0')
			return 0;
		if (*str != *text)
			return 0;
		str++;
		text++;
	}

	if ((text >= pdu_end) || (*text == '\0')
	    || (*text != ISCSI_TEXT_SEPARATOR)) {
		return 0;
	}

	/* find the value */
	value = text + 1;

	/* find the end of the value */
	while ((text < pdu_end) && (*text))
		text++;

	if (value_start)
		*value_start = value;
	if (value_end)
		*value_end = text;

	return 1;
}

static enum iscsi_login_status
get_auth_key_type(struct iscsi_acl *auth_client, char **data, char *end)
{
	char *key;
	char *value = NULL;
        char *value_end = NULL;
	char *text = *data;

	int keytype = AUTH_KEY_TYPE_NONE;

	while (acl_get_next_key_type(&keytype) == AUTH_STATUS_NO_ERROR) {
		key = (char *)acl_get_key_name(keytype);

		if (key && iscsi_find_key_value(key, text, end, &value,
						&value_end)) {
			if (acl_recv_key_value(auth_client, keytype, value) !=
					       AUTH_STATUS_NO_ERROR) {
				iscsi_err("login negotiation failed, can't "
					  "accept %s in security stage\n",
					  text);
				return LOGIN_NEGOTIATION_FAILED;
			}
			text = value_end;
			*data = text;
			return LOGIN_OK;
		}
	}
	iscsi_err("Login negotiation failed, can't accept %s in security "
		  "stage\n", text);
	return LOGIN_NEGOTIATION_FAILED;
}

static enum iscsi_login_status
get_security_text_keys(struct iscsi_session *session, char **data,
		       struct iscsi_acl *auth_client, char *end)
{
	char *text = *data;
	char *value = NULL;
	char *value_end = NULL;
	size_t size;
	int tag;
	enum iscsi_login_status ret;

	/*
	 * a few keys are possible in Security stage
	 * which the auth code doesn't care about, but
	 * which we might want to see, or at least not
	 * choke on.
	 */
	if (iscsi_find_key_value("TargetAlias", text, end, &value,
		&value_end)) {
		size = value_end - value;
		session->target_alias = kmalloc(size + 1, GFP_ATOMIC);
		if (!session->target_alias) {
			/* Alias not critical. So just print an error */
			iscsi_host_err(session, "Login failed to allocate "
				       "alias\n");
			*data = value_end;
			return LOGIN_OK;
		}
		memcpy(session->target_alias, value, size);
		session->target_alias[size] = '\0';
		text = value_end;
	} else if (iscsi_find_key_value("TargetAddress", text, end, &value,
					 &value_end)) {
		/*
		 * if possible, change the session's
		 * ip_address and port to the new
		 * TargetAddress
		 */
		if (iscsi_update_address(session, value)) {
			text = value_end;
		} else {
			iscsi_host_err(session, "Login redirection failed, "
				       "can't handle redirection to %s\n",
				       value);
			return LOGIN_REDIRECTION_FAILED;
		}
	} else if (iscsi_find_key_value("TargetPortalGroupTag", text, end,
					 &value, &value_end)) {
		/*
		 * We should have already obtained this
		 * via discovery.
		 * We've already picked an isid, so the
		 * most we can do is confirm we reached
		 * the portal group we were expecting to
		 */
		tag = simple_strtoul(value, NULL, 0);
		if (session->portal_group_tag >= 0) {
			if (tag != session->portal_group_tag) {
				iscsi_host_err(session, "Portal group tag "
					       "mismatch, expected %u, "
					       "received %u\n",
					       session->portal_group_tag, tag);
				return LOGIN_WRONG_PORTAL_GROUP;
			}
		} else
			/* we now know the tag */
			session->portal_group_tag = tag;

		text = value_end;
	} else {
		/*
		 * any key we don't recognize either
		 * goes to the auth code, or we choke
		 * on it
		 */
		ret = get_auth_key_type(auth_client, &text, end);
		if (ret != LOGIN_OK)
			return ret;
	}
	*data = text;
	return LOGIN_OK;
}

static enum iscsi_login_status
get_op_params_text_keys(struct iscsi_session *session, char **data, char *end)
{
	char *text = *data;
	char *value = NULL;
	char *value_end = NULL;
	size_t size;

	if (iscsi_find_key_value("TargetAlias", text, end, &value,
				 &value_end)) {
		size = value_end - value;
		if (session->target_alias &&
		    strlen(session->target_alias) == size &&
		    memcmp(session->target_alias, value, size) == 0) {
			*data = value_end;
			return LOGIN_OK;
		}
		kfree(session->target_alias);
		session->target_alias = kmalloc(size + 1, GFP_ATOMIC);
		if (!session->target_alias) {
			/* Alias not critical. So just print an error */
			iscsi_host_err(session, "Login failed to allocate "
				       "alias\n");
			*data = value_end;
			return LOGIN_OK;
		}
		memcpy(session->target_alias, value, size);
		session->target_alias[size] = '\0';
		text = value_end;
	} else if (iscsi_find_key_value("TargetAddress", text, end, &value,
					 &value_end)) {
		if (iscsi_update_address(session, value))
			text = value_end;
		else {
			iscsi_host_err(session, "Login redirection failed, "
				       "can't handle redirection to %s\n",
				       value);
			return LOGIN_REDIRECTION_FAILED;
		}
	} else if (iscsi_find_key_value("TargetPortalGroupTag", text, end,
					 &value, &value_end)) {
		/*
		 * confirm we reached the portal group we were expecting to
		 */
		int tag = simple_strtoul(value, NULL, 0);
		if (session->portal_group_tag >= 0) {
			if (tag != session->portal_group_tag) {
				iscsi_host_err(session, "Portal group tag "
					       "mismatch, expected %u, "
					       "received %u\n",
					       session->portal_group_tag, tag);
				return LOGIN_WRONG_PORTAL_GROUP;
			}
		} else
			/* we now know the tag */
			session->portal_group_tag = tag;

		text = value_end;
	} else if (iscsi_find_key_value("InitialR2T", text, end, &value,
					 &value_end)) {
		if (session->type == ISCSI_SESSION_TYPE_NORMAL) {
			if (value && (strcmp(value, "Yes") == 0))
				session->initial_r2t = 1;
			else
				session->initial_r2t = 0;
		} else
			session->irrelevant_keys_bitmap |=
						IRRELEVANT_INITIALR2T;
		text = value_end;
	} else if (iscsi_find_key_value("ImmediateData", text, end, &value,
					 &value_end)) {
		if (session->type == ISCSI_SESSION_TYPE_NORMAL) {
			if (value && (strcmp(value, "Yes") == 0))
				session->immediate_data = 1;
			else
				session->immediate_data = 0;
		} else
			session->irrelevant_keys_bitmap |=
						IRRELEVANT_IMMEDIATEDATA;
		text = value_end;
	} else if (iscsi_find_key_value("MaxRecvDataSegmentLength", text, end,
				     &value, &value_end)) {
		session->max_xmit_data_segment_len =
					    simple_strtoul(value, NULL, 0);
		text = value_end;
	} else if (iscsi_find_key_value("FirstBurstLength", text, end, &value,
					 &value_end)) {
		if (session->type == ISCSI_SESSION_TYPE_NORMAL)
			session->first_burst_len =
					    	simple_strtoul(value, NULL, 0);
		else
			session->irrelevant_keys_bitmap |=
						IRRELEVANT_FIRSTBURSTLENGTH;
		text = value_end;
	} else if (iscsi_find_key_value("MaxBurstLength", text, end, &value,
					 &value_end)) {
		/*
		 * we don't really care, since it's a  limit on the target's
		 * R2Ts, but record it anwyay
		 */
		if (session->type == ISCSI_SESSION_TYPE_NORMAL)
			session->max_burst_len = simple_strtoul(value, NULL, 0);
		else
			session->irrelevant_keys_bitmap |=
						IRRELEVANT_MAXBURSTLENGTH;
		text = value_end;
	} else if (iscsi_find_key_value("HeaderDigest", text, end, &value,
					 &value_end)) {
		if (strcmp(value, "None") == 0) {
			if (session->header_digest != ISCSI_DIGEST_CRC32C)
				session->header_digest = ISCSI_DIGEST_NONE;
			else {
				iscsi_host_err(session, "Login negotiation "
					       "failed, HeaderDigest=CRC32C "
					       "is required, can't accept "
					       "%s\n", text);
				return LOGIN_NEGOTIATION_FAILED;
			}
		} else if (strcmp(value, "CRC32C") == 0) {
			if (session->header_digest != ISCSI_DIGEST_NONE)
				session->header_digest = ISCSI_DIGEST_CRC32C;
			else {
				iscsi_host_err(session, "Login negotiation "
					       "failed, HeaderDigest=None is "
					       "required, can't accept %s\n",
					       text);
				return LOGIN_NEGOTIATION_FAILED;
			}
		} else {
			iscsi_host_err(session, "Login negotiation failed, "
				       "can't accept %s\n", text);
			return LOGIN_NEGOTIATION_FAILED;
		}
		text = value_end;
	} else if (iscsi_find_key_value("DataDigest", text, end, &value,
					 &value_end)) {
		if (strcmp(value, "None") == 0) {
			if (session->data_digest != ISCSI_DIGEST_CRC32C)
				session->data_digest = ISCSI_DIGEST_NONE;
			else {
				iscsi_host_err(session, "Login negotiation "
					       "failed, DataDigest=CRC32C "
					       "is required, can't accept "
					       "%s\n", text);
				return LOGIN_NEGOTIATION_FAILED;
			}
		} else if (strcmp(value, "CRC32C") == 0) {
			if (session->data_digest != ISCSI_DIGEST_NONE)
				session->data_digest = ISCSI_DIGEST_CRC32C;
			else {
				iscsi_host_err(session, "Login negotiation "
					       "failed, DataDigest=None is "
					       "required, can't accept %s\n",
					       text);
				return LOGIN_NEGOTIATION_FAILED;
			}
		} else {
			iscsi_host_err(session, "Login negotiation failed, "
				       "can't accept %s\n", text);
			return LOGIN_NEGOTIATION_FAILED;
		}
		text = value_end;
	} else if (iscsi_find_key_value("DefaultTime2Wait", text, end, &value,
					 &value_end)) {
		session->def_time2wait = simple_strtoul(value, NULL, 0);
		text = value_end;
	} else if (iscsi_find_key_value("DefaultTime2Retain", text, end,
					 &value, &value_end)) {
		session->def_time2retain = simple_strtoul(value, NULL, 0);
		text = value_end;
	} else if (iscsi_find_key_value("OFMarker", text, end, &value,
					 &value_end))
		/* result function is AND, target must honor our No */
		text = value_end;
	else if (iscsi_find_key_value("OFMarkInt", text, end, &value,
					 &value_end))
		/* we don't do markers, so we don't care */
		text = value_end;
	else if (iscsi_find_key_value("IFMarker", text, end, &value,
					 &value_end))
		/* result function is AND, target must honor our No */
		text = value_end;
	else if (iscsi_find_key_value("IFMarkInt", text, end, &value,
					 &value_end))
		/* we don't do markers, so we don't care */
		text = value_end;
	else if (iscsi_find_key_value("DataPDUInOrder", text, end, &value,
					 &value_end)) {
		if (session->type == ISCSI_SESSION_TYPE_NORMAL) {
			if (value && strcmp(value, "Yes") == 0)
				session->data_pdu_in_order = 1;
			else
				session->data_pdu_in_order = 0;
		} else
			session->irrelevant_keys_bitmap |=
						IRRELEVANT_DATAPDUINORDER;
		text = value_end;
	} else if (iscsi_find_key_value ("DataSequenceInOrder", text, end,
					 &value, &value_end)) {
		if (session->type == ISCSI_SESSION_TYPE_NORMAL)
			if (value && strcmp(value, "Yes") == 0)
				session->data_seq_in_order = 1;
			else
				session->data_seq_in_order = 0;
		else
			session->irrelevant_keys_bitmap |=
						IRRELEVANT_DATASEQUENCEINORDER;
		text = value_end;
	} else if (iscsi_find_key_value("MaxOutstandingR2T", text, end, &value,
					 &value_end)) {
		if (session->type == ISCSI_SESSION_TYPE_NORMAL) {
			if (strcmp(value, "1")) {
				iscsi_host_err(session, "Login negotiation "
					       "failed, can't accept Max"
					       "OutstandingR2T %s\n", value);
				return LOGIN_NEGOTIATION_FAILED;
			}
		} else
			session->irrelevant_keys_bitmap |=
						IRRELEVANT_MAXOUTSTANDINGR2T;
		text = value_end;
	} else if (iscsi_find_key_value("MaxConnections", text, end, &value,
					 &value_end)) {
		if (session->type == ISCSI_SESSION_TYPE_NORMAL) {
			if (strcmp(value, "1")) {
				iscsi_host_err(session, "Login negotiation "
					       "failed, can't accept Max"
					       "Connections %s\n", value);
				return LOGIN_NEGOTIATION_FAILED;
			}