Start to cleanup handling of the state file, save some space and uses linked lists.

1 files changed, 104 insertions, 103 deletions

diff --git a/networking/ifupdown.c b/networking/ifupdown.c
index 3e18df19e..37185327b 100644
--- a/networking/ifupdown.c
+++ b/networking/ifupdown.c
@@ -1,12 +1,14 @@
 /*
  *  ifupdown for busybox
- *  Based on ifupdown by Anthony Towns
+ *  Copyright (c) 2002 Glenn McGrath <bug1@optushome.com.au>
+ *
+ *  Based on ifupdown v 0.6.4 by Anthony Towns
  *  Copyright (c) 1999 Anthony Towns <aj@azure.humbug.org.au>
  *
  *  Changes to upstream version
- *  Remove checks for kernel version, assume kernel version 2.2.0 or better
+ *  Remove checks for kernel version, assume kernel version 2.2.0 or better.
  *  Lines in the interfaces file cannot wrap.
- *  The default state file is moved to /var/run/ifstate
+ *  To adhere to the FHS, the default state file is /var/run/ifstate.
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -39,10 +41,11 @@
 #include <unistd.h>
 
 #include "libbb.h"
-//#include "busybox.h"
-//#include "config.h"
 
-#define IFUPDOWN_VERSION "0.6.4"
+#define MAX_OPT_DEPTH 10
+#define EUNBALBRACK 10001
+#define EUNDEFVAR   10002
+#define EUNBALPER   10000
 
 typedef struct interface_defn_s interface_defn_t;
 
@@ -95,22 +98,13 @@ struct interface_defn_s {
 };
 
 typedef struct interfaces_file_s {
-        int max_autointerfaces;
-        int n_autointerfaces;
-        char **autointerfaces;
-
+        llist_t *autointerfaces;
         interface_defn_t *ifaces;
         mapping_defn_t *mappings;
 } interfaces_file_t;
 
-#define MAX_OPT_DEPTH 10
-#define EUNBALBRACK 10001
-#define EUNDEFVAR   10002
-#define MAX_VARNAME    32
-#define EUNBALPER   10000
-
-static int no_act = 0;
-static int verbose = 0;
+static char no_act = 0;
+static char verbose = 0;
 static char **environ = NULL;
 
 static void addstr(char **buf, size_t *len, size_t *pos, char *str, size_t str_length)
@@ -608,6 +602,17 @@ static int duplicate_if(interface_defn_t *ifa, interface_defn_t *ifb)
         return(1);
 }
 
+static const llist_t *find_list_string(const llist_t *list, const char *string)
+{
+        while (list) {
+                if (strcmp(list->data, string) == 0) {
+                        return(list);
+                }
+                list = list->link;
+        }
+        return(NULL);
+}
+
 static interfaces_file_t *read_interfaces(char *filename)
 {
         interface_defn_t *currif = NULL;
@@ -624,7 +629,7 @@ static interfaces_file_t *read_interfaces(char *filename)
         enum { NONE, IFACE, MAPPING } currently_processing = NONE;
 
         defn = xmalloc(sizeof(interfaces_file_t));
-        defn->max_autointerfaces = defn->n_autointerfaces = 0;
+//      defn->max_autointerfaces = defn->n_autointerfaces = 0;
         defn->autointerfaces = NULL;
         defn->mappings = NULL;
         defn->ifaces = NULL;
@@ -752,26 +757,14 @@ static interfaces_file_t *read_interfaces(char *filename)
                         currently_processing = IFACE;
                 } else if (strcmp(firstword, "auto") == 0) {
                         while ((rest = next_word(rest, firstword, 80))) {
-                                int i;
-
-                                for (i = 0; i < defn->n_autointerfaces; i++) {
-                                        if (strcmp(firstword, defn->autointerfaces[i]) == 0) {
-                                                perror_msg("interface declared auto twice \"%s\"", buf);
-                                                return NULL;
-                                        }
-                                }
-
-                                if (defn->n_autointerfaces == defn->max_autointerfaces) {
-                                        char **tmp;
 
-                                        defn->max_autointerfaces *= 2;
-                                        defn->max_autointerfaces++;
-                                        tmp = xrealloc(defn->autointerfaces, sizeof(*tmp) * defn->max_autointerfaces);
-                                        defn->autointerfaces = tmp;
+                                /* Check the interface isnt already listed */
+                                if (find_list_string(defn->autointerfaces, firstword)) {
+                                        perror_msg_and_die("interface declared auto twice \"%s\"", buf);
                                 }
 
-                                defn->autointerfaces[defn->n_autointerfaces] = xstrdup(firstword);
-                                defn->n_autointerfaces++;
+                                /* Add the interface to the list */
+                                defn->autointerfaces = llist_add_to(defn->autointerfaces, strdup(firstword));
                         }
                         currently_processing = NONE;
                 } else {
@@ -1095,29 +1088,19 @@ static int run_mapping(char *physical, char *logical, int len, mapping_defn_t *
 }
 #endif /* CONFIG_FEATURE_IFUPDOWN_IPV6 */
 
-static int lookfor_iface(char **ifaces, int n_ifaces, char *iface)
+static llist_t *find_iface_state(llist_t *state_list, const char *iface)
 {
-        int i;
+        unsigned short iface_len = xstrlen(iface);
+        llist_t *search = state_list;
 
-        for (i = 0; i < n_ifaces; i++) {
-                if (strncmp(iface, ifaces[i], xstrlen(iface)) == 0) {
-                        if (ifaces[i][xstrlen(iface)] == '=') {
-                                return i;
-                        }
+        while (search) {
+                if ((strncmp(search->data, iface, iface_len) == 0) &&
+                        (search->data[iface_len] == '=')) {
+                        return(search);
                 }
+                search = search->link;
         }
-
-        return(-1);
-}
-
-static void add_to_state(char ***ifaces, int *n_ifaces, int *max_ifaces, char *new_iface)
-{
-        if (*max_ifaces == *n_ifaces) {
-                *max_ifaces = (*max_ifaces * 2) + 1;
-                *ifaces = xrealloc(*ifaces, sizeof(**ifaces) * *max_ifaces);
-        }
-
-        (*ifaces)[(*n_ifaces)++] = new_iface;
+        return(NULL);
 }
 
 extern int ifupdown_main(int argc, char **argv)
@@ -1125,19 +1108,16 @@ extern int ifupdown_main(int argc, char **argv)
         int (*cmds) (interface_defn_t *) = NULL;
         interfaces_file_t *defn;
         FILE *state_fp = NULL;
-        char **target_iface = NULL;
-        char **state = NULL;    /* list of iface=liface */
+        llist_t *state_list = NULL;
+        llist_t *target_list = NULL;
         char *interfaces = "/etc/network/interfaces";
-        char *statefile = "/var/run/ifstate";
+        const char *statefile = "/var/run/ifstate";
 
 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
         int run_mappings = 1;
 #endif
         int do_all = 0;
         int force = 0;
-        int n_target_ifaces = 0;
-        int n_state = 0;
-        int max_state = 0;
         int i;
 
         if (applet_name[2] == 'u') {
@@ -1195,11 +1175,13 @@ extern int ifupdown_main(int argc, char **argv)
                 error_msg_and_die("couldn't read interfaces file \"%s\"", interfaces);
         }
 
-        state_fp = fopen(statefile, no_act ? "r" : "a+");
-        if (state_fp == NULL && !no_act) {
-                perror_msg_and_die("failed to open statefile %s", statefile);
+        if (no_act) {
+                state_fp = fopen(statefile, "r");
+        } else {
+                state_fp = xfopen(statefile, "a+");
         }
 
+        /* Read the previous state from the state file */
         if (state_fp != NULL) {
                 char *start;
                 while ((start = get_line_from_file(state_fp)) != NULL) {
@@ -1207,61 +1189,65 @@ extern int ifupdown_main(int argc, char **argv)
                         /* We should only need to check for a single character */
                         end_ptr = start + strcspn(start, " \t\n");
                         *end_ptr = '\0';
-                        add_to_state(&state, &n_state, &max_state, start);
+                        state_list = llist_add_to(state_list, start);
                 }
         }
 
+        /* Create a list of interfaces to work on */
         if (do_all) {
                 if (cmds == iface_up) {
-                        target_iface = defn->autointerfaces;
-                        n_target_ifaces = defn->n_autointerfaces;
+                        target_list = defn->autointerfaces;
                 } else if (cmds == iface_down) {
-                        target_iface = state;
-                        n_target_ifaces = n_state;
+                        const llist_t *list = state_list;
+                        while (list) {
+                                target_list = llist_add_to(target_list, strdup(list->data));
+                                list = list->link;
+                        }
                 }
         } else {
-                target_iface = argv + optind;
-                n_target_ifaces = argc - optind;
+                target_list = llist_add_to(target_list, argv[optind]);
         }
 
 
-        for (i = 0; i < n_target_ifaces; i++) {
+        /* Update the interfaces */
+        while (target_list) {
                 interface_defn_t *currif;
-                char iface[80];
-                char liface[80];
+                char *iface;
+                char *liface;
                 char *pch;
                 int okay = 0;
 
-                strncpy(iface, target_iface[i], sizeof(iface));
-                iface[sizeof(iface) - 1] = '\0';
+                iface = strdup(target_list->data);
+                target_list = target_list->link;
 
-                if ((pch = strchr(iface, '='))) {
+                pch = strchr(iface, '=');
+                if (pch) {
                         *pch = '\0';
-                        strncpy(liface, pch + 1, sizeof(liface));
-                        liface[sizeof(liface) - 1] = '\0';
+                        liface = strdup(pch + 1);
                 } else {
-                        strncpy(liface, iface, sizeof(liface));
-                        liface[sizeof(liface) - 1] = '\0';
+                        liface = strdup(iface);
                 }
+
                 if (!force) {
-                        int already_up = lookfor_iface(state, n_state, iface);;
+                        const llist_t *iface_state = find_iface_state(state_list, iface);
 
                         if (cmds == iface_up) {
                                 /* ifup */
-                                if (already_up != -1) {
+                                if (iface_state) {
                                         error_msg("interface %s already configured", iface);
                                         continue;
                                 }
                         } else {
                                 /* ifdown */
-                                if (already_up == -1) {
+                                if (iface_state == NULL) {
                                         error_msg("interface %s not configured", iface);
                                         continue;
                                 }
-                                strncpy(liface, strchr(state[already_up], '=') + 1, 80);
-                                liface[79] = 0;
+                                pch = strchr(iface_state->data, '=');
+                                liface = strdup(pch + 1);
                         }
                 }
+
 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
                 if ((cmds == iface_up) && run_mappings) {
                         mapping_defn_t *currmap;
@@ -1286,13 +1272,13 @@ extern int ifupdown_main(int argc, char **argv)
                                 char *oldiface = currif->iface;
 
                                 okay = 1;
-
                                 currif->iface = iface;
 
                                 if (verbose) {
                                         error_msg("Configuring interface %s=%s (%s)", iface, liface, currif->address_family->name);
                                 }
 
+                                /* Call the cmds function pointer, does either iface_up() or iface_down() */
                                 if (cmds(currif) == -1) {
                                         printf
                                                 ("Don't seem to be have all the variables for %s/%s.\n",
@@ -1306,39 +1292,54 @@ extern int ifupdown_main(int argc, char **argv)
                 if (!okay && !force) {
                         error_msg("Ignoring unknown interface %s=%s.", iface, liface);
                 } else {
-                        int already_up = lookfor_iface(state, n_state, iface);
+                        llist_t *iface_state = find_iface_state(state_list, iface);
 
                         if (cmds == iface_up) {
                                 char *newiface = xmalloc(xstrlen(iface) + 1 + xstrlen(liface) + 1);
                                 sprintf(newiface, "%s=%s", iface, liface);
-                                if (already_up == -1) {
-                                        add_to_state(&state, &n_state, &max_state, newiface);
+                                if (iface_state == NULL) {
+                                        state_list = llist_add_to(state_list, newiface);
                                 } else {
-                                        free(state[already_up]);
-                                        state[already_up] = newiface;
+                                        free(iface_state->data);
+                                        iface_state->data = newiface;
                                 }
                         } else if (cmds == iface_down) {
-                                if (already_up != -1) {
-                                        state[already_up] = state[--n_state];
+                                /* Remove an interface from the linked list */
+                                if (iface_state) {
+                                        /* This needs to be done better */
+                                        free(iface_state->data);
+                                        free(iface_state->link);
+                                        if (iface_state->link) {
+                                                iface_state->data = iface_state->link->data;
+                                                iface_state->link = iface_state->link->link;
+                                        } else {
+                                                iface_state->data = NULL;
+                                                iface_state->link = NULL;
+                                        }                                               
                                 }
                         }
                 }
-                if (state_fp != NULL && !no_act) {
-                        unsigned short j;
+        }
 
-                        if (ftruncate(fileno(state_fp), 0) < 0) {
-                                error_msg_and_die("failed to truncate statefile %s: %s", statefile, strerror(errno));
-                        }
+        /* Actually write the new state */
+        if (state_fp != NULL && !no_act) {
+                if (ftruncate(fileno(state_fp), 0) < 0) {
+                        error_msg_and_die("failed to truncate statefile %s: %s", statefile, strerror(errno));
+                }
+
+                rewind(state_fp);
 
-                        rewind(state_fp);
-                        for (j = 0; j < n_state; j++) {
-                                fputs(state[i], state_fp);
+                while (state_list) {
+                        if (state_list->data) {
+                                fputs(state_list->data, state_fp);
                                 fputc('\n', state_fp);
                         }
-                        fflush(state_fp);
+                        state_list = state_list->link;
                 }
+                fflush(state_fp);
         }
 
+        /* Cleanup */
         if (state_fp != NULL) {
                 fclose(state_fp);
                 state_fp = NULL;