cmd/listen/nstoa.c

/*
 * 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 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*  Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */


#pragma ident   "%Z%%M% %I% %E% SMI"

/*
    stoa - convert string to address

    If a string begins in \o or \O, the following address is octal
    "  "   "       "    " \x or \X, the following address is hex
    Otherwise, a string is considered text. Text may be quoted
    with double quotes and the C-like escapes \n, \b, \t, \v, \r, and \nnn
    (nnn = octal char) are recognized.
    A \ followed by a newline causes the newline
    to vanish. A \ followed by any other char causes any "magic" of
    any other char to disappear.

    Other escape sequences recognized are:
        \!cmd args [ \! || EOL ]
    which is replaced by the raw output of the execution of cmd.
    This may only be used in a string.

        \$cmd args [ \$ || EOL ]
    which is replaced by the output of the execution of cmd and
    is then reprocessed.

    A  NULL is returned on any error(s).
*/

#include <stdio.h>
#include <memory.h>
#include <ctype.h>
#include "nsaddr.h"


#define toupper(c)  (islower(c) ? _toupper(c) : (c))
#define todigit(c)  ((int)((c) - '0'))  /* char to digit */
#define toxdigit(c) ((isdigit(c))?todigit(c):(toupper(c)-(int)'A'+10))
#define isodigit(c) (isdigit(c) && ((c) != '9') && ((c) != '8'))
#define itoac(i)    (((i) > 9) ? ((char)((i)-10) + 'A'):((char)(i) + '0'))
#define MASK(n)     ((1 << (n)) - 1)

#define MAXRLEVEL   10  /* maximum recursion level */

#define TRUE    1;
#define FALSE   0;

char    scanbuf[SBUFSIZE];
int sbp = 0;
int rec = 0;    /* Recursion level */

char    sbuf[SBUFSIZE];

extern void free();

struct netbuf *
stoa(str, addr)         /* Return 0 for success, -1 for error */
char    *str;
struct netbuf   *addr;
{
    char    *xfer(), *prescan();

    int myadr;      /* was netbuf struct allocated here ? */
    int quote;      /* quoted string ? */

    myadr = FALSE;

    if (!str)
        return NULL;
    while (*str && isspace(*str))   /* leading whites are OK */
        ++str;

    str = prescan(str);     /* Do all \$ ... \$ */

    if (!str || !*str) return NULL;     /* Nothing to convert */

    if (!addr) {
        if ((addr = (struct netbuf *)malloc(sizeof(struct netbuf))) == NULL)
            return NULL;
        myadr = TRUE;
        addr->buf = NULL;
        addr->maxlen = 0;
        addr->len = 0;
    }

    /* Now process the address */
    quote = 0;

    if (*str == '\\') {
        ++str;
        switch (*str) {

        case 'X':   /* hex */
        case 'x':
            addr->len = dobase(++str, sbuf, HEX);
            break;

        case 'o':   /* octal */
        case 'O':
            addr->len = dobase(++str, sbuf, OCT);
            break;

        case '\0':  /* No address given!, length is 0 */
            addr->len = dostring(str, sbuf, 0);
            break;

        default:    /* \ is handled by dostring */
            addr->len = dostring(--str, sbuf, quote);
            break;
        }
    }
    else {
        if (*str == '"') {  /* quoted string */
            quote = 1;
            ++str;
        }
        addr->len = dostring(str, sbuf, quote);
    }

    if (addr->len == 0) {   /* Error in conversion */
        if (myadr)
            free(addr);
        return NULL;
    }
    if ((addr->buf = xfer(addr->buf, sbuf, addr->len, addr->maxlen)) == NULL)
        return NULL;
    else
        return addr;
}


/*
    dostring:   Copy string at s to buf translating
        escaped characters and shell escapes.
    return length of string.
*/

int
dostring(s, buf, quote)     /* read in a raw address */
char    *s, *buf;
int quote;
{
    char    *xcmd();

    int oc, ch, len = 0;
    int l = 0;
    char    *rout;

    while (*s) {
        if (len >= SBUFSIZE) {
            fprintf(stderr, "dostring: string too long\n");
            break;
        }
        else if (*s == '\\')
            switch(*++s) {

            case '!':   /* raw shell escape */
                if (rout = xcmd(s+1, '!', &s, &l)) {
                    if (len + l < SBUFSIZE)
                        memcpy(buf+len, rout, l);
                    len += l;
                    free(rout);
                }
                break;

            case '\n':  /* ignore newline */
                ++s;
                break;

            case 'b':   /* backspace */
                buf[len++] = '\b'; s++;
                break;

            case 'n':   /* newline */
                buf[len++] = '\n'; s++;
                break;

            case 'r':   /* return */
                buf[len++] = '\r'; s++;
                break;

            case 't':   /* horiz. tab */
                buf[len++] = '\t'; s++;
                break;

            case 'v':   /* vert. tab */
                buf[len++] = '\v'; s++;

            case '0':
            case '1':
            case '2':
            case '3':
                for(oc=ch=0; (*s >= '0' && *s <= '7') && oc++ < 3; ++s)
                    ch = (ch << 3) | (*s - '0');
                buf[len++] = ch;
                break;

            case 0:     /* end of string -- terminate */
                break;

            default:    /* take the character blindly */
                buf[len++] = *s++;
                break;
            }
        else if ((quote && (*s == '"')) || (!quote && isspace(*s)))
            break;

        else
            buf[len++] = *s++;
    }
    return (len >= SBUFSIZE) ? 0 : len;
}


/*
    dobase :    converts a hex or octal ASCII string
        to a binary address. Only HEX or OCT may be used
        for type.
    return length of binary string (in bytes), 0 if error.
    The binary result is placed at buf.
*/

int
dobase(s, buf, type)    /* read in an address */
char    *s, *buf;   /* source ASCII, result binary string */
int type;
{
    void    memcp();
    int bp = SBUFSIZE - 1;
    int shift = 0;
    char    *end;

    for (end = s; *end && ((type == OCT) ? isodigit(*end) :
        isxdigit(*end)); ++end) ;

    /* any non-white, non-digits cause address to be rejected,
       other fields are ignored */

    if ((*s == 0) || (end == s) || (!isspace(*end) && *end)) {
        fprintf(stderr, "dobase: Illegal trailer on address string\n");
        buf[0] = '\0';
        return 0;
    }
    --end;

    buf[bp] = '\0';

    while (bp > 0 && end >= s) {
        buf[bp] |= toxdigit(*end) << shift;
        if (type == OCT) {
            if (shift > 5) {
                buf[--bp] = (todigit(*end) >> (8 - shift))
                    & MASK(shift-5);
            }
            if ((shift = (shift + 3) % 8) == 0)
                buf[--bp] = 0;
        }
        else    /* hex */
            if ((shift = (shift) ? 0 : 4) == 0)
                buf[--bp] = 0;;
        --end;
    }
    if (bp == 0) {
        fprintf(stderr, "stoa: dobase: number to long\n");
        return 0;
    }

    /* need to catch end case to avoid extra 0's in front   */
    if (!shift)
        bp++;
    memcp(buf, &buf[bp], (SBUFSIZE - bp));
    return (SBUFSIZE - bp);
}

#ifdef NOTUSED


/*

    atos(str, addr, type)

    convert address to ASCII form with address in hex, octal,
    or character form.
    return pointer to buffer (NULL on failure).
*/


char *
atos(str, addr, type)
char    *str;
struct netbuf   *addr;
int type;
{
    char    *xfer();
    int mystr = 0;  /* was str allocated here ? */
    unsigned    x_atos(), o_atos();
    void    memcp();

    char    *base;

    if (addr == NULL)
        return NULL;

    if (str == NULL)
        if ((str = malloc(SBUFSIZE)) == NULL)
            return NULL;
        else
            mystr = 1;

    switch (type) {

    case OCT:
        /* first add \o */
        sbuf[0] = '\\';
        sbuf[1] = 'o';

        return xfer(str, sbuf, o_atos(sbuf+2, addr->buf, addr->len) + 2,
            mystr ? SBUFSIZE : 0);

    case HEX:
        /* first add \x */
        sbuf[0] = '\\';
        sbuf[1] = 'x';

        return xfer(str, sbuf, x_atos(sbuf+2, addr->buf, addr->len) + 2,
            mystr ? SBUFSIZE : 0);

    case RAW:
        base = xfer(str, addr->buf,
             addr->len + 1, mystr ? SBUFSIZE : 0);
        if (base)
            base[addr->len] = '\0'; /* terminate*/
        return base;

    default:
        return NULL;
    }
}


/*
    x_atos, o_atos
    return the number of bytes occupied by string + NULL*/

/*
    x_atos :    convert an address string a, length s
        to hex ASCII in s */


unsigned
x_atos(s, a, l)
char    *s, *a;
unsigned    l;
{
    char    *b;

    b = s;
    while (l--) {
        *s++ = itoac(((*a >> 4) & MASK (4)));
        *s++ = itoac((*a & MASK(4)));
        ++a;
    }
    *s = '\0';
    return (s - b + 1);
}


/*
    o_atos :    convert an address a, length l
        to octal ASCII in s   */


unsigned
o_atos(s, a, l)
char    *s, *a;
unsigned    l;
{
    int i, shift;
    char    *b;

    b = s;
    if (l == 0) {
        *s = '\0';
        return 0;
    }

    /* take care of partial bits and set shift factor for next 3  */

    i = l % 3;
    *s++ = itoac((*a>>(i+5)) & MASK(3-i));
    shift = 2 + i;

    while (l)
        if (shift <= 5) {
            *s++ = itoac((*a >> shift) & MASK(3));
            if (shift == 0) {
                ++a;
                --l;
            }
            shift += (shift < 3) ? 5 : -3;
        }
        else {
            i = (*a & MASK(shift-5)) << (8-shift);
            i |= (*++a >> shift) & MASK(8-shift);
            *s++ = itoac(i);
            shift -= 3;
            --l;
        }
    *s++ = '\0';
    return (s - b + 1);
}

#endif /* NOTUSED */

void
memcp(d, s, n)  /* safe memcpy for overlapping regions */
char    *d, *s;
int n;
{
    while (n--)
        *d++ = *s++;
}


/* transfer block to a given destination or allocate one of the
    right size
    if max = 0 : ignore max
*/

char *
xfer(dest, src, len, max)
char    *dest, *src;
unsigned    len, max;
{
    if (max && dest && max < len) {     /* No room */
        fprintf(stderr, "xfer: destination not long enough\n");
        return NULL;
    }
    if (!dest)
        if ((dest = (char *)malloc(len)) == NULL) {
            fprintf(stderr, "xfer: malloc failed\n");
            return NULL;
        }

    memcpy(dest, src, (int)len);
    return dest;
}

/*
    prescan:    scan through string s, expanding all \$...\$
        as shell escapes.
    Return pointer to string of expanded text.
*/

char *
prescan(s)
char    *s;
{
    int scan();

    rec = sbp = 0;
    if (!s || !*s || !scan(s))
        return NULL;
    scanbuf[sbp] = '\0';
    return scanbuf;
}


/*
    scan:   scan through string s, expanding all \$...\$.
    (Part II of prescan)
    Return 0 if anything failed, else 1.
*/

int
scan(s)
char    *s;
{
    char    *xcmd();
    char    *cmd;
    int len;
    int esc = 0;        /* Keep lookout for \\$ */

    while (*s) {
        if (!esc && (*s == '\\' && *(s+1) == '$')) {
            if (rec++ == MAXRLEVEL) {
                fprintf(stderr, "scan: Recursion \
level past %d on shell escape\n", rec);
                return 0;
            }
            if ((cmd = xcmd(s+2, '$', &s, &len)) != NULL) {
                cmd[len] = '\0';
                if (*cmd != '\0')
                    scan(cmd);
                free(cmd);
            }
            else
                return 0;
        }

        else if (sbp == SBUFSIZE) {
            fprintf(stderr, "Overflow on shell esc expansion\n");
            return 0;
        }
        else if (sbp < SBUFSIZE)
            esc = ((scanbuf[sbp++] = *s++) == '\\');
    }
    return 1;
}


/*
    xcmd :  extract command line for shell escape and execute it
        return pointer to output of command
*/

char *
xcmd(s, ec, ps, len)
char    *s;     /* input string */
char    ec;     /* escape char ( $ or ! ) */
char    **ps;       /* address of input string pointer */
int *len;       /* Number of bytes of output from command */
{
    FILE    *popen();
    int pclose();

    FILE    *pfp;       /* pipe for process */
    char    *cmd;       /* command buffer */
    char    *cmdp;      /* pointer along cmd */
    char    *ocmd;      /* output of command buffer */
    int esc = 0;    /* escaped escape shell */

    *len = 0;

    if ((cmd = cmdp = (char *)malloc(SBUFSIZE)) == NULL) {
        fprintf(stderr, "xcmd: malloc failed\n");
        return NULL;
    }

    if ((ocmd = (char *)malloc(SBUFSIZE)) == NULL) {
        fprintf(stderr, "xcmd: malloc failed\n");
        free(cmd);
        return NULL;
    }
    while (*s) {
        if (!esc && *s == '\\' && *(s+1) == ec) {
            s += 2;
            break;
        }
        else
            esc = (*cmdp++ = *s++) == '\\';
    }
    *cmdp = '\0';
    *ps = s;

    if ((pfp = popen(cmd, "r")) == NULL)
        fprintf(stderr, "xcmd: popen failed\n");
    while (fread(&ocmd[*len], 1, 1, pfp))
        if ((*len += 1) >= SBUFSIZE) {
            fprintf(stderr, "xcmd: command output too long\n");
            break;
        }
    pclose(pfp);
    free(cmd);

    return ocmd;
}