/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Miscellaneous Utilities
 *
 * slp_err:             Error and information message dispatch, i18n'd
 * slp_start_call:      Marks a SLP handle as in-use
 * slp_end_call:        Marks a SLP handle as available
 * slp_map_err:         protocol to API error mapping
 * slp_onlist:          determines if a token is on a list
 * slp_add2list:        adds a token to a list
 * slp_list_subtract:   removes a token from a list
 * slp_add_header:      creates a SLP message header
 * slp_get_length:      gets the length field from a SLP header
 * slp_set_length:      sets the length field in a SLP header
 * slp_header_get_sht:  gets a 16 bit integer from a SLP header
 * slp_header_set_sht:  sets a 16 bit interger in a SLP header
 * slp_header_length:   calculates the length of a header, including the
 *                              language tag
 * slp_get_errcode:     returns the error code from a SLP message
 * slp_add_byte:        encodes a byte into the given buffer
 * slp_add_sht:         encodes a 16-bit integer into the given buffer
 * slp_add_string:      encodes the given string into the given buffer
 * slp_get_byte:        decodes a byte from the given buffer
 * slp_get_sht:         decodes a 16-bit integer from the given buffer
 * slp_get_string:      decodes a string from the given buffer
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <syslog.h>
#include <string.h>
#include <thread.h>
#include <synch.h>
#include <errno.h>
#include <unistd.h>
#include <limits.h>
#include <arpa/inet.h>
#include <libintl.h>
#include <slp-internal.h>

#define SLP_ERR_BUF_LEN 1024UL

/*
 * Outputs an error message. priority is a syslog(3) priority.
 */
/*ARGSUSED1*/
/* PRINTFLIKE4 */
void slp_err(int priority, int id, char *func, char *inmsg, ...) {
        static char buf[SLP_ERR_BUF_LEN];
        char *p, *msg;
        size_t len;
        va_list ap;
        static mutex_t loglock = DEFAULTMUTEX;
        va_start(ap, inmsg);

        (void) mutex_lock(&loglock);

        /* i18n mapping */
        msg = dgettext("libslp", inmsg);

        (void) snprintf(buf, sizeof (buf), "libslp: %s: ", func);
        len = strlen(buf);
        p = &(buf[len]);
        (void) vsnprintf(p, SLP_ERR_BUF_LEN - len, msg, ap);
        va_end(ap);
        syslog(priority, buf);
        (void) mutex_unlock(&loglock);
}

/*
 * Start and end slp calls
 * slp_start_call returns SLP_HANDLE_IN_USE if the handle is already
 * being used, otherwise SLP_OK.
 */
SLPError slp_start_call(slp_handle_impl_t *hp) {
        (void) mutex_lock(&(hp->outcall_lock));
        if (hp->pending_outcall) {
            (void) mutex_unlock(&(hp->outcall_lock));
            return (SLP_HANDLE_IN_USE);
        }
        hp->pending_outcall = SLP_TRUE;
        (void) mutex_unlock(&(hp->outcall_lock));

        hp->cancel = 0;
        return (SLP_OK);
}

void slp_end_call(slp_handle_impl_t *hp) {
        (void) mutex_lock(&(hp->outcall_lock));
        if (hp->close_on_end) {
            /* SLPClose() called from callback */
            (void) mutex_unlock(&(hp->outcall_lock));
            slp_cleanup_handle(hp);
            return;
        }

        hp->pending_outcall = SLP_FALSE;
        (void) cond_signal(&(hp->outcall_cv));
        (void) mutex_unlock(&(hp->outcall_lock));
}

/*
 * Map a protocol error code to an API error code.
 */
SLPError slp_map_err(unsigned short proto_err) {
        switch (proto_err) {
        case 0: return (SLP_OK);
        case 1: return (SLP_LANGUAGE_NOT_SUPPORTED);
        case 2: return (SLP_PARSE_ERROR);
        case 3: return (SLP_INVALID_REGISTRATION);
        case 4: return (SLP_SCOPE_NOT_SUPPORTED);
        case 6: return (SLP_AUTHENTICATION_ABSENT);
        case 7: return (SLP_AUTHENTICATION_FAILED);
        case 13:        return (SLP_INVALID_UPDATE);
                /*
                 * 9 (VER_NOT_SUPPORTED), 10 (INTERNAL_ERROR),
                 * 11 (DA_BUSY_NOW), 12 (OPTION_NOT_UNDERSTOOD),
                 * and 14 (RQST_NOT_SUPPORTED)
                 * should be handled internally by the API.
                 */
        default:        return (SLP_INTERNAL_SYSTEM_ERROR);
        }
}

/*
 * SLP List Management:
 * SLP lists are comma separated lists of tokens. The following routines
 * manage SLP lists, ensuring proper UTF-8 parsing.
 */

/*
 * If 'item' is on 'list', returns 1, otherwise 0.
 */
int slp_onlist(const char *item, const char *list) {
        char *p;
        for (p = (char *)list; p; p++) {
                char *s;
                size_t span;

                s = p;
                p = slp_utf_strchr(p, ',');
                span = (p ? (size_t)(p - s): strlen(s));

                if (strlen(item) != span) {
                        if (!p)
                                break;
                        else
                                continue;
                }

                if (strncasecmp(item, s, span) == 0)
                        return (1);
                if (!p)
                        break;
        }
        return (0);
}

/*
 * Adds item to *list if it is not already on it. If *list == NULL,
 * creates a new list. When it grows the list, it will free *list,
 * so *list must not be on the caller's stack. 'check_onlist' specifies
 * whether to look to item on the current list. This is a small
 * optimization for callers which are that item is not on *list, or
 * which don't care about duplicates.
 */
void slp_add2list(const char *item, char **list, SLPBoolean check_onlist) {
        if (!(*list)) {
                if (!(*list = strdup(item)))
                        slp_err(LOG_CRIT, 0, "slp_add2list", "out of memory");
                return;
        }

        if (check_onlist)
                /* no duplicates */
                if (slp_onlist(item, *list))
                        return;

        if (!(*list = realloc(*list, strlen(*list) + strlen(item) + 2))) {
                slp_err(LOG_CRIT, 0, "slp_add2list", "out of memory");
                return;
        }
        (void) strcat(*list, ",");
        (void) strcat(*list, item);
}

/*
 * Removes the first instance of item from *list.
 * When it shrinks the list, it may free *list, so *list must not be on
 * the caller's stack.
 */
void slp_list_subtract(const char *item, char **list) {
        char *p, *s;

        if (!*list || !slp_onlist(item, *list))
                return;
        /* find item's location on the list */
        for (p = *list; p; p++) {
                size_t span;

                s = p;
                p = slp_utf_strchr(p, ',');
                span = (p ? (size_t)(p - s) : strlen(s));
                if (strlen(item) != span)
                        continue;
                if (strncasecmp(item, s, span) == 0)
                        break;
                if (!p)
                        break;
        }
        if (!p && s == *list) {
                /* item is only one on list */
                free(*list);
                *list = NULL;
                return;
        }
        if (!p) {
                /* last one on list; just chop it off */
                s--;
                *s = 0;
                return;
        }
        /* either first on list, or somewhere in the middle */
        (void) strcpy(s, p + 1);
}

/* SLPv2 header management */

/*
 * Lays a SLP header into pcSendBuf, performing byte-ordering and bounds
 * checking where necessary.
 * pcLangTag: Language tag
 * pcSendBuf: a buffer into which to write the composed header
 * iSendBufSz: the size of pcSendBuf in bytes
 * iFun: SLP V2 function number
 * iLen: The length of the whole SLP message, in bytes
 * piLen: a pointer to an int into which will be written the size of the
 *        header + the language tag (i.e. the offset at which the rest of
 *        the message should be written into pcSendBuf).
 */
SLPError slp_add_header(const char *pcLangTag, char *pcSendBuf,
                        size_t iSendBufSz, int iFun,
                        size_t iLen, size_t *piLen) {
        unsigned short us, xid;
        static unsigned short xid_seeded = 0;

        if (!xid_seeded) {
                static mutex_t lock = DEFAULTMUTEX;
                (void) mutex_lock(&lock);
                if (!xid_seeded) {
                        /* generate a seed based on our PID */
                        long long pid = getpid();
                        pid *= UINT_MAX;
                        (void) seed48((unsigned short *) &pid);
                        xid_seeded = 1;
                }
                (void) mutex_unlock(&lock);
        }
        /* squish the random value into an unsigned short */
        xid = (unsigned short) (lrand48() % USHRT_MAX);
        xid = xid ? xid : 1;    /* 0 is for DAs only */

        us = (unsigned short) strlen(pcLangTag);
        if ((SLP_HDRLEN + us) > iSendBufSz)
                return (SLP_PARAMETER_BAD);

        (void) memset(pcSendBuf, 0, SLP_HDRLEN);

        slp_set_version(pcSendBuf, SLP_VERSION);
        slp_set_function(pcSendBuf, (char)iFun);
        slp_set_length(pcSendBuf, iLen);
        slp_set_xid(pcSendBuf, xid);
        slp_set_langlen(pcSendBuf, us);
        (void) memcpy(&pcSendBuf[SLP_HDRLEN], pcLangTag, us);

        *piLen = SLP_HDRLEN + us;
        return (SLP_OK);
}

/*
 * Retrieves the 24 bit int stored at 'off' offset into 'header'.
 * Assumes 'header' is a valid SLP message header.
 */
unsigned int slp_header_get_int24(const char *header, size_t off) {
        unsigned int len;

        len = ((unsigned int)(header[off] & 0xff)) << 16;
        len += ((unsigned int)(header[off + 1] & 0xff)) << 8;
        len += ((unsigned int)(header[off + 2] & 0xff));

        return (len);
}

/*
 * Sets a 24 bit int at the location in 'header' 'off' bytes
 * offset into the header.
 * Assumes 'header' is a valid SLP message header.
 */
void slp_header_set_int24(char *header, unsigned int len, size_t off) {
        header[off] = (unsigned char) ((len & 0xff0000) >> 16);
        header[off + 1] = (unsigned char) ((len & 0xff00) >> 8);
        header[off + 2] = (unsigned char) (len & 0xff);
}

/*
 * Retrieves the 16 bit integer stored at 'off' offset into 'header'.
 * Assumes 'header' is a valid SLP message header.
 */
unsigned short slp_header_get_sht(const char *header, size_t off) {
        unsigned short answer = 0;
        (void) slp_get_sht(header, SLP_HDRLEN, &off, &answer);
        return (answer);
}

/*
 * Sets a 16 bit interger at the location in 'header' 'off' bytes
 * offset into the header.
 * Assumes 'header' is a valid SLP message header.
 */
void slp_header_set_sht(char *header, unsigned short len, size_t off) {
        (void) slp_add_sht(header, SLP_HDRLEN, len, &off);
}

/*
 * Returns the total length of a SLP header associated with the SLP
 * handle 'hp', including the language tag.
 */
size_t slp_header_length(slp_handle_impl_t *hp) {
        return (SLP_HDRLEN + strlen(hp->locale));
}

/*
 * Retrieves the error code for UA replies -- the errcode is always
 * the first short after the header for these functions. 'msg' points to
 * the beginning of a SLP header.
 */
slp_proto_err slp_get_errcode(char *msg) {
        unsigned short langlen, errcode;
        size_t off, msglen;

        /* make sure the reply is long enough */
        msglen = slp_get_length(msg);
        if (msglen < (SLP_LANGLEN + 2))
                return (SLP_MSG_PARSE_ERROR);
        langlen = slp_get_langlen(msg);
        off = SLP_HDRLEN + langlen;

        if (slp_get_sht(msg, msglen, &off, &errcode) != SLP_OK)
                return (SLP_MSG_PARSE_ERROR);

        return (errcode);
}

/*
 * Primitive Encoding and Decoding Routines.
 * All perform byte-ordering coversions and bounds checking.
 */

SLPError slp_add_byte(char *pcBuf, size_t iBufSz, int iVal,
                        size_t *piLen) {
        if ((*piLen + 1) > iBufSz)
                return (SLP_PARAMETER_BAD);

        pcBuf[(*piLen)++] = (unsigned char) iVal;
        return (SLP_OK);
}

SLPError slp_add_sht(char *pcBuf, size_t iBufSz, unsigned short iVal,
                        size_t *piLen) {
        if ((*piLen + 2) > iBufSz)
                return (SLP_PARAMETER_BAD);

        pcBuf[(*piLen)++] = (unsigned char) ((iVal & 0xFF00) >> 8);
        pcBuf[(*piLen)++] = (unsigned char) (iVal & 0xFF);
        return (SLP_OK);
}

SLPError slp_add_int32(char *pcBuf, size_t iBufSz, unsigned int iVal,
                        size_t *piLen) {
        if ((*piLen + 4) > iBufSz)
                return (SLP_PARAMETER_BAD);

        pcBuf[(*piLen)++] = (unsigned char) ((iVal & 0xFF000000) >> 24);
        pcBuf[(*piLen)++] = (unsigned char) ((iVal & 0xFF0000) >> 16);
        pcBuf[(*piLen)++] = (unsigned char) ((iVal & 0xFF00) >> 8);
        pcBuf[(*piLen)++] = (unsigned char) (iVal & 0xFF);

        return (SLP_OK);
}

SLPError slp_add_string(char *pcBuf, size_t iBufSz, const char *pcStr,
                        size_t *piLen) {
        size_t iStrLen = strlen(pcStr);
        SLPError err = 0;

        if (iStrLen > USHRT_MAX)
                /* SLP strings are limited to 16-bit len */
                return (SLP_PARAMETER_BAD);
        if ((iStrLen + *piLen + 2) > iBufSz)
                return (SLP_PARAMETER_BAD);

        if ((err = slp_add_sht(pcBuf, iBufSz, (unsigned short)iStrLen, piLen))
            != SLP_OK)
                return (err);

        (void) memcpy(&(pcBuf[*piLen]), pcStr, iStrLen);
        *piLen += iStrLen;
        return (SLP_OK);
}

SLPError slp_get_byte(const char *pcBuf, size_t maxlen,
                        size_t *piOffset, int *piByte) {
        size_t offset = 0;

        if (piOffset != NULL) {
                if ((*piOffset+1) > maxlen)
                        return (SLP_PARSE_ERROR);
                offset = *piOffset;
                *piOffset += 1;
        }

        *piByte = (int)pcBuf[offset];
        return (SLP_OK);
}

SLPError slp_get_sht(const char *pcBuf, size_t maxlen,
                        size_t *piOffset, unsigned short *piSht) {
        size_t offset = 0;

        if (piOffset != NULL) {
                if ((*piOffset+2) > maxlen)
                        return (SLP_PARSE_ERROR);
                offset = *piOffset;
                *piOffset += 2;
        }

        *piSht = (unsigned short)
                ((unsigned char)pcBuf[offset] & (unsigned char)0xFF);
        *piSht <<= 8;
        *piSht += (unsigned short)
                ((unsigned char)pcBuf[offset+1] & (unsigned char)0xFF);

        return (SLP_OK);
}

SLPError slp_get_int32(const char *pcBuf, size_t maxlen,
                        size_t *piOffset, unsigned int *piInt) {
        size_t offset = 0;

        if (piOffset != NULL) {
                if ((*piOffset+4) > maxlen)
                        return (SLP_PARSE_ERROR);
                offset = *piOffset;
                *piOffset += 4;
        }

        *piInt = ((unsigned int)(pcBuf[offset] & 0xff)) << 24;
        *piInt += ((unsigned int)(pcBuf[offset+1] & 0xff)) << 16;
        *piInt += ((unsigned int)(pcBuf[offset+2] & 0xff)) << 8;
        *piInt += ((unsigned int)(pcBuf[offset+3] & 0xff));

        return (SLP_OK);
}

SLPError slp_get_string(const char *pcBuf, size_t iMaxLen,
                    size_t *piOffset, char **ppcString) {
        SLPError err;
        unsigned short iLen;

        *ppcString = NULL;
        err = slp_get_sht(pcBuf, iMaxLen, piOffset, &iLen);
        if (err)
                return (err);
        if ((iLen+*piOffset) > iMaxLen)
                return (SLP_PARSE_ERROR);

        if (!(*ppcString = malloc(iLen + 1))) {
                slp_err(LOG_CRIT, 0, "slp_get_string", "out of memory");
                return (SLP_MEMORY_ALLOC_FAILED);
        }
        (void) memcpy(*ppcString, pcBuf + *piOffset, iLen);
        (*ppcString)[iLen] = 0;
        *piOffset += iLen;
        return (SLP_OK);
}