diff options
Diffstat (limited to 'networking/udhcp/script.c')
| -rw-r--r-- | networking/udhcp/script.c | 37 |
1 files changed, 19 insertions, 18 deletions
diff --git a/networking/udhcp/script.c b/networking/udhcp/script.c index 7ebef35..94dabf4 100644 --- a/networking/udhcp/script.c +++ b/networking/udhcp/script.c @@ -14,7 +14,7 @@ /* get a rough idea of how long an option will be (rounding up...) */ -static const uint8_t max_option_length[] = { +static const uint8_t len_of_option_as_string[] = { [OPTION_IP] = sizeof("255.255.255.255 "), [OPTION_IP_PAIR] = sizeof("255.255.255.255 ") * 2, [OPTION_STRING] = 1, @@ -30,17 +30,10 @@ static const uint8_t max_option_length[] = { }; -static inline int upper_length(int length, int opt_index) -{ - return max_option_length[opt_index] * - (length / dhcp_option_lengths[opt_index]); -} - - /* note: ip is a pointer to an IP in network order, possibly misaliged */ static int sprint_nip(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]); + return sprintf(dest, "%s%u.%u.%u.%u", pre, ip[0], ip[1], ip[2], ip[3]); } @@ -57,9 +50,10 @@ static int mton(uint32_t mask) } -/* 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) +/* Create "opt_name=opt_value" string */ +static char *xmalloc_optname_optval(uint8_t *option, const struct dhcp_option *type_p, const char *opt_name) { + unsigned upper_length; int len, type, optlen; uint16_t val_u16; int16_t val_s16; @@ -67,14 +61,16 @@ static char *alloc_fill_opts(uint8_t *option, const struct dhcp_option *type_p, int32_t val_s32; char *dest, *ret; - len = option[OPT_LEN - 2]; + /* option points to OPT_DATA, need to go back and get OPT_LEN */ + len = option[OPT_LEN - OPT_DATA]; type = type_p->flags & TYPE_MASK; optlen = dhcp_option_lengths[type]; + upper_length = len_of_option_as_string[type] * (len / optlen); - dest = ret = xmalloc(upper_length(len, type) + strlen(opt_name) + 2); + dest = ret = xmalloc(upper_length + strlen(opt_name) + 2); dest += sprintf(ret, "%s=", opt_name); - for (;;) { + while (len >= optlen) { switch (type) { case OPTION_IP_PAIR: dest += sprint_nip(dest, "", option); @@ -114,15 +110,20 @@ static char *alloc_fill_opts(uint8_t *option, const struct dhcp_option *type_p, case OPTION_STR1035: /* unpack option into dest; use ret for prefix (i.e., "optname=") */ dest = dname_dec(option, len, ret); - free(ret); - return dest; + if (dest) { + free(ret); + return dest; + } + /* error. return "optname=" string */ + return ret; #endif } option += optlen; len -= optlen; if (len <= 0) break; - dest += sprintf(dest, " "); + *dest++ = ' '; + *dest = '\0'; } return ret; } @@ -174,7 +175,7 @@ static char **fill_envp(struct dhcp_packet *packet) temp = get_option(packet, dhcp_options[i].code); if (!temp) goto next; - *curr = alloc_fill_opts(temp, &dhcp_options[i], opt_name); + *curr = xmalloc_optname_optval(temp, &dhcp_options[i], opt_name); putenv(*curr++); /* Fill in a subnet bits option for things like /24 */ |