busybox

/* vi: set sw=4 ts=4: */

/* script.c

 *

 * Functions to call the DHCP client notification scripts

 *

 * Russ Dill <Russ.Dill@asu.edu> July 2001

 *

 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.

 */

​

#include "common.h"

#include "dhcpc.h"

#include "options.h"

​

​

/* get a rough idea of how long an option will be (rounding up...) */

static const uint8_t max_option_length[] = {

    [OPTION_IP] =       sizeof("255.255.255.255 "),

    [OPTION_IP_PAIR] =  sizeof("255.255.255.255 ") * 2,

    [OPTION_STRING] =   1,

#if ENABLE_FEATURE_UDHCP_RFC3397

    [OPTION_STR1035] =  1,

#endif

    [OPTION_BOOLEAN] =  sizeof("yes "),

    [OPTION_U8] =       sizeof("255 "),

    [OPTION_U16] =      sizeof("65535 "),

    [OPTION_S16] =      sizeof("-32768 "),

    [OPTION_U32] =      sizeof("4294967295 "),

    [OPTION_S32] =      sizeof("-2147483684 "),

};

​

​

static inline int upper_length(int length, int opt_index)

{

    return max_option_length[opt_index] *

        (length / dhcp_option_lengths[opt_index]);

}

​

​

static int sprintip(char *dest, const char *pre, const uint8_t *ip)

{

    return sprintf(dest, "%s%d.%d.%d.%d", pre, ip[0], ip[1], ip[2], ip[3]);

}

​

​

/* really simple implementation, just count the bits */

static int mton(uint32_t mask)

{

    int i = 0;

    mask = ntohl(mask); /* 111110000-like bit pattern */

    while (mask) {

        i++;

        mask <<= 1;

    }

    return i;

}

​

​

/* Allocate and fill with the text of option 'option'. */

static char *alloc_fill_opts(uint8_t *option, const struct dhcp_option *type_p, const char *opt_name)

{

    int len, type, optlen;

    uint16_t val_u16;

    int16_t val_s16;

    uint32_t val_u32;

    int32_t val_s32;

    char *dest, *ret;

​

    len = option[OPT_LEN - 2];

    type = type_p->flags & TYPE_MASK;

    optlen = dhcp_option_lengths[type];

​

    dest = ret = xmalloc(upper_length(len, type) + strlen(opt_name) + 2);

    dest += sprintf(ret, "%s=", opt_name);

​

    for (;;) {

        switch (type) {

        case OPTION_IP_PAIR:

            dest += sprintip(dest, "", option);

            *dest++ = '/';

            option += 4;

            optlen = 4;

        case OPTION_IP: /* Works regardless of host byte order. */

            dest += sprintip(dest, "", option);

            break;

        case OPTION_BOOLEAN:

            dest += sprintf(dest, *option ? "yes" : "no");

            break;

        case OPTION_U8:

            dest += sprintf(dest, "%u", *option);

            break;

        case OPTION_U16: