From 1e18f1bab3400246129756a35bb5752ba98f4c90 Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Sat, 16 Feb 2008 13:19:19 +0000 Subject: [PATCH] ifupdowm: shrink 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 | 199 +++++++++++++++++++++--------------------- 1 file changed, 100 insertions(+), 99 deletions(-) diff --git a/networking/ifupdown.c b/networking/ifupdown.c index a794bf76a..d0d7bfe5b 100644 --- a/networking/ifupdown.c +++ b/networking/ifupdown.c @@ -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); - continue; /* blank line */ + 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/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]); + 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]); - return 0; - case 0: /* child */ - dup2(infd[0], 0); - dup2(outfd[1], 1); - close(infd[0]); - 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;