*: more readable handling of pipe fds. No code changes.
[oweals/busybox.git] / networking / udhcp / script.c
index 07f68362c3ecd2a17e884f822c34f8d16d9cbf0e..71f0333280bdbc2b8f6882c4c5129819973fc9f3 100644 (file)
@@ -9,16 +9,18 @@
  */
 
 #include "common.h"
-#include "dhcpd.h"
 #include "dhcpc.h"
 #include "options.h"
 
 
 /* get a rough idea of how long an option will be (rounding up...) */
-static const int max_option_length[] = {
+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_RFC3397
+       [OPTION_STR1035] =      1,
+#endif
        [OPTION_BOOLEAN] =      sizeof("yes "),
        [OPTION_U8] =           sizeof("255 "),
        [OPTION_U16] =          sizeof("65535 "),
@@ -31,48 +33,51 @@ static const int max_option_length[] = {
 static inline int upper_length(int length, int opt_index)
 {
        return max_option_length[opt_index] *
-               (length / option_lengths[opt_index]);
+               (length / dhcp_option_lengths[opt_index]);
 }
 
 
-static int sprintip(char *dest, char *pre, uint8_t *ip)
+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(struct in_addr *mask)
+static int mton(uint32_t mask)
 {
-       int i;
-       unsigned long bits = ntohl(mask->s_addr);
-       /* too bad one can't check the carry bit, etc in c bit
-        * shifting */
-       for (i = 0; i < 32 && !((bits >> i) & 1); i++);
-       return 32 - i;
+       int i = 0;
+       mask = ntohl(mask); /* 111110000-like bit pattern */
+       while (mask) {
+               i++;
+               mask <<= 1;
+       }
+       return i;
 }
 
 
-/* Fill dest with the text of option 'option'. */
-static void fill_options(char *dest, uint8_t *option,
-                       const struct dhcp_option *type_p)
+/* 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 type, optlen;
+       int len, type, optlen;
        uint16_t val_u16;
        int16_t val_s16;
        uint32_t val_u32;
        int32_t val_s32;
-       int len = option[OPT_LEN - 2];
-
-       dest += sprintf(dest, "%s=", type_p->name);
+       char *dest, *ret;
 
+       len = option[OPT_LEN - 2];
        type = type_p->flags & TYPE_MASK;
-       optlen = option_lengths[type];
+       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++) = '/';
+                       *dest++ = '/';
                        option += 4;
                        optlen = 4;
                case OPTION_IP: /* Works regardless of host byte order. */
@@ -103,13 +108,21 @@ static void fill_options(char *dest, uint8_t *option,
                case OPTION_STRING:
                        memcpy(dest, option, len);
                        dest[len] = '\0';
-                       return;  /* Short circuit this case */
+                       return ret;      /* Short circuit this case */
+#if ENABLE_FEATURE_RFC3397
+               case OPTION_STR1035:
+                       /* unpack option into dest; use ret for prefix (i.e., "optname=") */
+                       dest = dname_dec(option, len, ret);
+                       free(ret);
+                       return dest;
+#endif
                }
                option += optlen;
                len -= optlen;
                if (len <= 0) break;
                dest += sprintf(dest, " ");
        }
+       return ret;
 }
 
 
@@ -119,51 +132,63 @@ static char **fill_envp(struct dhcpMessage *packet)
        int num_options = 0;
        int i, j;
        char **envp;
+       char *var;
+       const char *opt_name;
        uint8_t *temp;
-       struct in_addr subnet;
        char over = 0;
 
-       if (packet == NULL)
-               num_options = 0;
-       else {
-               for (i = 0; dhcp_options[i].code; i++)
+       if (packet) {
+               for (i = 0; dhcp_options[i].code; i++) {
                        if (get_option(packet, dhcp_options[i].code)) {
                                num_options++;
                                if (dhcp_options[i].code == DHCP_SUBNET)
                                        num_options++; /* for mton */
                        }
-               if (packet->siaddr) num_options++;
-               if ((temp = get_option(packet, DHCP_OPTION_OVER)))
+               }
+               if (packet->siaddr)
+                       num_options++;
+               temp = get_option(packet, DHCP_OPTION_OVER);
+               if (temp)
                        over = *temp;
-               if (!(over & FILE_FIELD) && packet->file[0]) num_options++;
-               if (!(over & SNAME_FIELD) && packet->sname[0]) num_options++;
+               if (!(over & FILE_FIELD) && packet->file[0])
+                       num_options++;
+               if (!(over & SNAME_FIELD) && packet->sname[0])
+                       num_options++;
        }
 
        envp = xzalloc(sizeof(char *) * (num_options + 5));
        j = 0;
        envp[j++] = xasprintf("interface=%s", client_config.interface);
-       envp[j++] = xasprintf("PATH=%s",
-               getenv("PATH") ? : "/bin:/usr/bin:/sbin:/usr/sbin");
-       envp[j++] = xasprintf("HOME=%s", getenv("HOME") ? : "/");
+       var = getenv("PATH");
+       if (var)
+               envp[j++] = xasprintf("PATH=%s", var);
+       var = getenv("HOME");
+       if (var)
+               envp[j++] = xasprintf("HOME=%s", var);
 
-       if (packet == NULL) return envp;
+       if (packet == NULL)
+               return envp;
 
        envp[j] = xmalloc(sizeof("ip=255.255.255.255"));
        sprintip(envp[j++], "ip=", (uint8_t *) &packet->yiaddr);
 
-       for (i = 0; dhcp_options[i].code; i++) {
+       opt_name = dhcp_option_strings;
+       i = 0;
+       while (*opt_name) {
                temp = get_option(packet, dhcp_options[i].code);
                if (!temp)
-                       continue;
-               envp[j] = xmalloc(upper_length(temp[OPT_LEN - 2],
-                       dhcp_options[i].flags & TYPE_MASK) + strlen(dhcp_options[i].name) + 2);
-               fill_options(envp[j++], temp, &dhcp_options[i]);
+                       goto next;
+               envp[j++] = alloc_fill_opts(temp, &dhcp_options[i], opt_name);
 
                /* Fill in a subnet bits option for things like /24 */
                if (dhcp_options[i].code == DHCP_SUBNET) {
+                       uint32_t subnet;
                        memcpy(&subnet, temp, 4);
-                       envp[j++] = xasprintf("mask=%d", mton(&subnet));
+                       envp[j++] = xasprintf("mask=%d", mton(subnet));
                }
+ next:
+               opt_name += strlen(opt_name) + 1;
+               i++;
        }
        if (packet->siaddr) {
                envp[j] = xmalloc(sizeof("siaddr=255.255.255.255"));
@@ -195,19 +220,20 @@ void udhcp_run_script(struct dhcpMessage *packet, const char *name)
        DEBUG("vfork'ing and execle'ing %s", client_config.script);
 
        envp = fill_envp(packet);
+
        /* call script */
+// can we use wait4pid(spawn(...)) here?
        pid = vfork();
-       if (pid) {
-               waitpid(pid, NULL, 0);
-               for (curr = envp; *curr; curr++) free(*curr);
-               free(envp);
-               return;
-       } else if (pid == 0) {
+       if (pid < 0) return;
+       if (pid == 0) {
                /* close fd's? */
                /* exec script */
                execle(client_config.script, client_config.script,
                       name, NULL, envp);
-               bb_perror_msg("script %s failed", client_config.script);
-               exit(1);
+               bb_perror_msg_and_die("script %s failed", client_config.script);
        }
+       safe_waitpid(pid, NULL, 0);
+       for (curr = envp; *curr; curr++)
+               free(*curr);
+       free(envp);
 }