ifupdowm: shrink
authorDenis Vlasenko <vda.linux@googlemail.com>
Sat, 16 Feb 2008 13:19:19 +0000 (13:19 -0000)
committerDenis Vlasenko <vda.linux@googlemail.com>
Sat, 16 Feb 2008 13:19:19 +0000 (13:19 -0000)
ifupdown_main                                       2170    2459    +289
find_iface_state                                      57      56      -1
next_word                                             63      58      -5
popen2                                               350       -    -350
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 1/2 up/down: 289/-356)          Total: -67 bytes

networking/ifupdown.c

index a794bf7..d0d7bfe 100644 (file)
@@ -590,8 +590,8 @@ static char *next_word(char **buf)
        /* Skip over leading whitespace */
        word = skip_whitespace(*buf);
 
-       /* Stop on EOL/comments */
-       if (*word == '#' || *word == '\0')
+       /* Stop on EOL */
+       if (*word == '\0')
                return NULL;
 
        /* Find the length of this word (can't be 0) */
@@ -652,40 +652,67 @@ static const llist_t *find_list_string(const llist_t *list, const char *string)
 
 static struct interfaces_file_t *read_interfaces(const char *filename)
 {
+       /* Let's try to be compatible.
+        *
+        * "man 5 interfaces" says:
+        * Lines starting with "#" are ignored. Note that end-of-line
+        * comments are NOT supported, comments must be on a line of their own.
+        * A line may be extended across multiple lines by making
+        * the last character a backslash.
+        *
+        * Seen elsewhere in example config file:
+        * A "#" character in the very first column makes the rest of the line
+        * be ignored. Blank lines are ignored. Lines may be indented freely.
+        * A "\" character at the very end of the line indicates the next line
+        * should be treated as a continuation of the current one.
+        */
 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
        struct mapping_defn_t *currmap = NULL;
 #endif
        struct interface_defn_t *currif = NULL;
        struct interfaces_file_t *defn;
        FILE *f;
-       char *firstword;
        char *buf;
-
+       char *first_word;
+       char *rest_of_line;
        enum { NONE, IFACE, MAPPING } currently_processing = NONE;
 
-       defn = xzalloc(sizeof(struct interfaces_file_t));
-
+       defn = xzalloc(sizeof(*defn));
        f = xfopen(filename, "r");
 
        while ((buf = xmalloc_getline(f)) != NULL) {
-               char *buf_ptr = buf;
-
-               firstword = next_word(&buf_ptr);
-               if (firstword == NULL) {
+#if ENABLE_DESKTOP
+               /* Trailing "\" concatenates lines */
+               char *p;
+               while ((p = last_char_is(buf, '\\')) != NULL) {
+                       *p = '\0';
+                       rest_of_line = xmalloc_getline(f);
+                       if (!rest_of_line)
+                               break;
+                       p = xasprintf("%s%s", buf, rest_of_line);
+                       free(buf);
+                       free(rest_of_line);
+                       buf = p;
+               }
+#endif
+               rest_of_line = buf;
+               first_word = next_word(&rest_of_line);
+               if (!first_word || *buf == '#') {
                        free(buf);
-                       continue;       /* blank line */
+                       continue; /* blank/comment line */
                }
 
-               if (strcmp(firstword, "mapping") == 0) {
+               if (strcmp(first_word, "mapping") == 0) {
 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
                        currmap = xzalloc(sizeof(*currmap));
 
-                       while ((firstword = next_word(&buf_ptr)) != NULL) {
+                       while ((first_word = next_word(&rest_of_line)) != NULL) {
                                if (currmap->n_matches >= currmap->max_matches) {
                                        currmap->max_matches = currmap->max_matches * 2 + 1;
-                                       currmap->match = xrealloc(currmap->match, sizeof(*currmap->match) * currmap->max_matches);
+                                       currmap->match = xrealloc(currmap->match,
+                                               sizeof(*currmap->match) * currmap->max_matches);
                                }
-                               currmap->match[currmap->n_matches++] = xstrdup(firstword);
+                               currmap->match[currmap->n_matches++] = xstrdup(first_word);
                        }
                        /*currmap->max_mappings = 0; - done by xzalloc */
                        /*currmap->n_mappings = 0;*/
@@ -702,7 +729,7 @@ static struct interfaces_file_t *read_interfaces(const char *filename)
                        debug_noise("Added mapping\n");
 #endif
                        currently_processing = MAPPING;
-               } else if (strcmp(firstword, "iface") == 0) {
+               } else if (strcmp(first_word, "iface") == 0) {
                        static const struct address_family_t *const addr_fams[] = {
 #if ENABLE_FEATURE_IFUPDOWN_IPV4
                                &addr_inet,
@@ -712,24 +739,23 @@ static struct interfaces_file_t *read_interfaces(const char *filename)
 #endif
                                NULL
                        };
-
                        char *iface_name;
                        char *address_family_name;
                        char *method_name;
                        llist_t *iface_list;
 
                        currif = xzalloc(sizeof(*currif));
-                       iface_name = next_word(&buf_ptr);
-                       address_family_name = next_word(&buf_ptr);
-                       method_name = next_word(&buf_ptr);
+                       iface_name = next_word(&rest_of_line);
+                       address_family_name = next_word(&rest_of_line);
+                       method_name = next_word(&rest_of_line);
 
                        if (method_name == NULL)
                                bb_error_msg_and_die("too few parameters for line \"%s\"", buf);
 
                        /* ship any trailing whitespace */
-                       buf_ptr = skip_whitespace(buf_ptr);
+                       rest_of_line = skip_whitespace(rest_of_line);
 
-                       if (buf_ptr[0] != '\0' /* && buf_ptr[0] != '#' */)
+                       if (rest_of_line[0] != '\0' /* && rest_of_line[0] != '#' */)
                                bb_error_msg_and_die("too many parameters \"%s\"", buf);
 
                        currif->iface = xstrdup(iface_name);
@@ -754,57 +780,59 @@ static struct interfaces_file_t *read_interfaces(const char *filename)
 
                        debug_noise("iface %s %s %s\n", currif->iface, address_family_name, method_name);
                        currently_processing = IFACE;
-               } else if (strcmp(firstword, "auto") == 0) {
-                       while ((firstword = next_word(&buf_ptr)) != NULL) {
+               } else if (strcmp(first_word, "auto") == 0) {
+                       while ((first_word = next_word(&rest_of_line)) != NULL) {
 
                                /* Check the interface isnt already listed */
-                               if (find_list_string(defn->autointerfaces, firstword)) {
+                               if (find_list_string(defn->autointerfaces, first_word)) {
                                        bb_perror_msg_and_die("interface declared auto twice \"%s\"", buf);
                                }
 
                                /* Add the interface to the list */
-                               llist_add_to_end(&(defn->autointerfaces), xstrdup(firstword));
-                               debug_noise("\nauto %s\n", firstword);
+                               llist_add_to_end(&(defn->autointerfaces), xstrdup(first_word));
+                               debug_noise("\nauto %s\n", first_word);
                        }
                        currently_processing = NONE;
                } else {
                        switch (currently_processing) {
                        case IFACE:
-                               if (buf_ptr[0] == '\0')
+                               if (rest_of_line[0] == '\0')
                                        bb_error_msg_and_die("option with empty value \"%s\"", buf);
 
-                               if (strcmp(firstword, "up") != 0
-                                && strcmp(firstword, "down") != 0
-                                && strcmp(firstword, "pre-up") != 0
-                                && strcmp(firstword, "post-down") != 0
+                               if (strcmp(first_word, "up") != 0
+                                && strcmp(first_word, "down") != 0
+                                && strcmp(first_word, "pre-up") != 0
+                                && strcmp(first_word, "post-down") != 0
                                ) {
                                        int i;
                                        for (i = 0; i < currif->n_options; i++) {
-                                               if (strcmp(currif->option[i].name, firstword) == 0)
+                                               if (strcmp(currif->option[i].name, first_word) == 0)
                                                        bb_error_msg_and_die("duplicate option \"%s\"", buf);
                                        }
                                }
                                if (currif->n_options >= currif->max_options) {
                                        currif->max_options += 10;
-                                       currif->option = xrealloc(currif->option, sizeof(*currif->option) * currif->max_options);
+                                       currif->option = xrealloc(currif->option,
+                                               sizeof(*currif->option) * currif->max_options);
                                }
-                               debug_noise("\t%s=%s\n", firstword, buf_ptr);
-                               currif->option[currif->n_options].name = xstrdup(firstword);
-                               currif->option[currif->n_options].value = xstrdup(buf_ptr);
+                               debug_noise("\t%s=%s\n", first_word, rest_of_line);
+                               currif->option[currif->n_options].name = xstrdup(first_word);
+                               currif->option[currif->n_options].value = xstrdup(rest_of_line);
                                currif->n_options++;
                                break;
                        case MAPPING:
 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
-                               if (strcmp(firstword, "script") == 0) {
+                               if (strcmp(first_word, "script") == 0) {
                                        if (currmap->script != NULL)
                                                bb_error_msg_and_die("duplicate script in mapping \"%s\"", buf);
-                                       currmap->script = xstrdup(next_word(&buf_ptr));
-                               } else if (strcmp(firstword, "map") == 0) {
+                                       currmap->script = xstrdup(next_word(&rest_of_line));
+                               } else if (strcmp(first_word, "map") == 0) {
                                        if (currmap->n_mappings >= currmap->max_mappings) {
                                                currmap->max_mappings = currmap->max_mappings * 2 + 1;
-                                               currmap->mapping = xrealloc(currmap->mapping, sizeof(char *) * currmap->max_mappings);
+                                               currmap->mapping = xrealloc(currmap->mapping,
+                                                       sizeof(char *) * currmap->max_mappings);
                                        }
-                                       currmap->mapping[currmap->n_mappings] = xstrdup(next_word(&buf_ptr));
+                                       currmap->mapping[currmap->n_mappings] = xstrdup(next_word(&rest_of_line));
                                        currmap->n_mappings++;
                                } else {
                                        bb_error_msg_and_die("misplaced option \"%s\"", buf);
@@ -817,7 +845,8 @@ static struct interfaces_file_t *read_interfaces(const char *filename)
                        }
                }
                free(buf);
-       }
+       } /* while (fgets) */
+
        if (ferror(f) != 0) {
                /* ferror does NOT set errno! */
                bb_error_msg_and_die("%s: I/O error", filename);
@@ -955,60 +984,39 @@ static int iface_down(struct interface_defn_t *iface)
 }
 
 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
-static int popen2(FILE **in, FILE **out, char *command, ...)
+static int popen2(FILE **in, FILE **out, char *command, char *param)
 {
-       va_list ap;
-       char *argv[11] = { command };
-       int argc;
+       char *argv[3] = { command, param, NULL };
        int infd[2], outfd[2];
        pid_t pid;
 
-       argc = 1;
-       va_start(ap, command);
-       while ((argc < 10) && (argv[argc] = va_arg(ap, char *))) {
-               argc++;
-       }
-       argv[argc] = NULL;      /* make sure */
-       va_end(ap);
-
-       if (pipe(infd) != 0) {
-               return 0;
-       }
-
-       if (pipe(outfd) != 0) {
-               close(infd[0]);
-               close(infd[1]);
-               return 0;
-       }
+       xpipe(infd);
+       xpipe(outfd);
 
        fflush(NULL);
-       switch (pid = fork()) {
-       case -1:                        /* failure */
-               close(infd[0]);
-               close(infd[1]);
-               close(outfd[0]);
-               close(outfd[1]);
-               return 0;
-       case 0:                 /* child */
-               dup2(infd[0], 0);
-               dup2(outfd[1], 1);
-               close(infd[0]);
+       pid = fork();
+
+       switch (pid) {
+       case -1:  /* failure */
+               bb_perror_msg_and_die("fork");
+       case 0:  /* child */
+               /* NB: close _first_, then move fds! */
                close(infd[1]);
                close(outfd[0]);
-               close(outfd[1]);
+               xmove_fd(infd[0], 0);
+               xmove_fd(outfd[1], 1);
                BB_EXECVP(command, argv);
-               exit(127);
-       default:                        /* parent */
-               *in = fdopen(infd[1], "w");
-               *out = fdopen(outfd[0], "r");
-               close(infd[0]);
-               close(outfd[1]);
-               return pid;
+               _exit(127);
        }
-       /* unreached */
+       /* parent */
+       close(infd[0]);
+       close(outfd[1]);
+       *in = fdopen(infd[1], "w");
+       *out = fdopen(outfd[0], "r");
+       return pid;
 }
 
-static char *run_mapping(char *physical, struct mapping_defn_t * map)
+static char *run_mapping(char *physical, struct mapping_defn_t *map)
 {
        FILE *in, *out;
        int i, status;
@@ -1016,12 +1024,8 @@ static char *run_mapping(char *physical, struct mapping_defn_t * map)
 
        char *logical = xstrdup(physical);
 
-       /* Run the mapping script. */
-       pid = popen2(&in, &out, map->script, physical, NULL);
-
-       /* popen2() returns 0 on failure. */
-       if (pid == 0)
-               return logical;
+       /* Run the mapping script. Never fails. */
+       pid = popen2(&in, &out, map->script, physical);
 
        /* Write mappings to stdin of mapping script. */
        for (i = 0; i < map->n_mappings; i++) {
@@ -1034,9 +1038,9 @@ static char *run_mapping(char *physical, struct mapping_defn_t * map)
                /* If the mapping script exited successfully, try to
                 * grab a line of output and use that as the name of the
                 * logical interface. */
-               char *new_logical = xmalloc(MAX_INTERFACE_LENGTH);
+               char *new_logical = xmalloc_getline(out);
 
-               if (fgets(new_logical, MAX_INTERFACE_LENGTH, out)) {
+               if (new_logical) {
                        /* If we are able to read a line of output from the script,
                         * remove any trailing whitespace and use this value
                         * as the name of the logical interface. */
@@ -1047,10 +1051,6 @@ static char *run_mapping(char *physical, struct mapping_defn_t * map)
 
                        free(logical);
                        logical = new_logical;
-               } else {
-                       /* If we are UNABLE to read a line of output, discard our
-                        * freshly allocated memory. */
-                       free(new_logical);
                }
        }
 
@@ -1062,12 +1062,13 @@ static char *run_mapping(char *physical, struct mapping_defn_t * map)
 
 static llist_t *find_iface_state(llist_t *state_list, const char *iface)
 {
-       unsigned short iface_len = strlen(iface);
+       unsigned iface_len = strlen(iface);
        llist_t *search = state_list;
 
        while (search) {
                if ((strncmp(search->data, iface, iface_len) == 0)
-                && (search->data[iface_len] == '=')) {
+                && (search->data[iface_len] == '=')
+               ) {
                        return search;
                }
                search = search->link;