diff options
Diffstat (limited to 'resolv/res_init.c')
| -rw-r--r-- | resolv/res_init.c | 222 |
1 files changed, 149 insertions, 73 deletions
diff --git a/resolv/res_init.c b/resolv/res_init.c index 659d3ea81f..5941d37f32 100644 --- a/resolv/res_init.c +++ b/resolv/res_init.c @@ -124,18 +124,75 @@ is_sort_mask (char ch) return ch == '/' || ch == '&'; } +/* Array of strings for the search array. The backing store is + managed separately. */ +#define DYNARRAY_STRUCT search_list +#define DYNARRAY_ELEMENT const char * +#define DYNARRAY_INITIAL_SIZE 4 +#define DYNARRAY_PREFIX search_list_ +#include <malloc/dynarray-skeleton.c> + +/* resolv.conf parser state and results. */ +struct resolv_conf_parser +{ + char *buffer; /* Temporary buffer for reading lines. */ + char *search_list_store; /* Backing storage for search list entries. */ + struct search_list search_list; /* Points into search_list_store. */ +}; + +static void +resolv_conf_parser_init (struct resolv_conf_parser *parser) +{ + parser->buffer = NULL; + parser->search_list_store = NULL; + search_list_init (&parser->search_list); +} + +static void +resolv_conf_parser_free (struct resolv_conf_parser *parser) +{ + free (parser->buffer); + free (parser->search_list_store); + search_list_free (&parser->search_list); +} + +/* Try to obtain the domain name from the host name and store it in + *RESULT. Return false on memory allocation failure. If the domain + name cannot be determined for any other reason, write NULL to + *RESULT and return true. */ +static bool +domain_from_hostname (char **result) +{ + char buf[256]; + /* gethostbyname may not terminate the buffer. */ + buf[sizeof (buf) - 1] = '\0'; + if (__gethostname (buf, sizeof (buf) - 1) == 0) + { + char *dot = strchr (buf, '.'); + if (dot != NULL) + { + *result = __strdup (dot + 1); + if (*result == NULL) + return false; + return true; + } + } + *result = NULL; + return true; +} + /* Internal helper function for __res_vinit, to aid with resource deallocation and error handling. Return true on success, false on failure. */ static bool -res_vinit_1 (res_state statp, bool preinit, FILE *fp, char **buffer) +res_vinit_1 (res_state statp, bool preinit, FILE *fp, + struct resolv_conf_parser *parser) { - char *cp, **pp; + char *cp; size_t buffer_size = 0; int nserv = 0; /* Number of nameservers read from file. */ bool have_serv6 = false; bool haveenv = false; - bool havesearch = false; int nsort = 0; char *net; @@ -162,39 +219,40 @@ res_vinit_1 (res_state statp, bool preinit, FILE *fp, char **buffer) /* Allow user to override the local domain definition. */ if ((cp = getenv ("LOCALDOMAIN")) != NULL) { - strncpy (statp->defdname, cp, sizeof (statp->defdname) - 1); - statp->defdname[sizeof (statp->defdname) - 1] = '\0'; + /* The code below splits the string in place. */ + cp = __strdup (cp); + if (cp == NULL) + return false; + free (parser->search_list_store); + parser->search_list_store = cp; haveenv = true; + /* The string will be truncated as needed below. */ + search_list_add (&parser->search_list, cp); + /* Set search list to be blank-separated strings from rest of env value. Permits users of LOCALDOMAIN to still have a search list, and anyone to set the one that they want to use as an individual (even more important now that the rfc1535 stuff restricts searches). */ - cp = statp->defdname; - pp = statp->dnsrch; - *pp++ = cp; - for (int n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) + for (bool in_name = true; *cp != '\0'; cp++) { if (*cp == '\n') - break; + { + *cp = '\0'; + break; + } else if (*cp == ' ' || *cp == '\t') { - *cp = 0; - n = 1; + *cp = '\0'; + in_name = false; } - else if (n > 0) + else if (!in_name) { - *pp++ = cp; - n = 0; - havesearch = true; + search_list_add (&parser->search_list, cp); + in_name = true; } } - /* Null terminate last domain if there are excess. */ - while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n') - cp++; - *cp = '\0'; - *pp++ = 0; } #define MATCH(line, name) \ @@ -210,7 +268,7 @@ res_vinit_1 (res_state statp, bool preinit, FILE *fp, char **buffer) while (true) { { - ssize_t ret = __getline (buffer, &buffer_size, fp); + ssize_t ret = __getline (&parser->buffer, &buffer_size, fp); if (ret <= 0) { if (_IO_ferror_unlocked (fp)) @@ -221,73 +279,82 @@ res_vinit_1 (res_state statp, bool preinit, FILE *fp, char **buffer) } /* Skip comments. */ - if (**buffer == ';' || **buffer == '#') + if (*parser->buffer == ';' || *parser->buffer == '#') continue; /* Read default domain name. */ - if (MATCH (*buffer, "domain")) + if (MATCH (parser->buffer, "domain")) { if (haveenv) /* LOCALDOMAIN overrides the configuration file. */ continue; - cp = *buffer + sizeof ("domain") - 1; + cp = parser->buffer + sizeof ("domain") - 1; while (*cp == ' ' || *cp == '\t') cp++; if ((*cp == '\0') || (*cp == '\n')) continue; - strncpy (statp->defdname, cp, sizeof (statp->defdname) - 1); - statp->defdname[sizeof (statp->defdname) - 1] = '\0'; - if ((cp = strpbrk (statp->defdname, " \t\n")) != NULL) + + cp = __strdup (cp); + if (cp == NULL) + return false; + free (parser->search_list_store); + parser->search_list_store = cp; + search_list_clear (&parser->search_list); + search_list_add (&parser->search_list, cp); + /* Replace trailing whitespace. */ + if ((cp = strpbrk (cp, " \t\n")) != NULL) *cp = '\0'; - havesearch = false; continue; } /* Set search list. */ - if (MATCH (*buffer, "search")) + if (MATCH (parser->buffer, "search")) { if (haveenv) /* LOCALDOMAIN overrides the configuration file. */ continue; - cp = *buffer + sizeof ("search") - 1; + cp = parser->buffer + sizeof ("search") - 1; while (*cp == ' ' || *cp == '\t') cp++; if ((*cp == '\0') || (*cp == '\n')) continue; - strncpy (statp->defdname, cp, sizeof (statp->defdname) - 1); - statp->defdname[sizeof (statp->defdname) - 1] = '\0'; - if ((cp = strchr (statp->defdname, '\n')) != NULL) - *cp = '\0'; + + { + char *p = strchr (cp, '\n'); + if (p != NULL) + *p = '\0'; + } + cp = __strdup (cp); + if (cp == NULL) + return false; + free (parser->search_list_store); + parser->search_list_store = cp; + + /* The string is truncated below. */ + search_list_clear (&parser->search_list); + search_list_add (&parser->search_list, cp); + /* Set search list to be blank-separated strings on rest of line. */ - cp = statp->defdname; - pp = statp->dnsrch; - *pp++ = cp; - for (int n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) + for (bool in_name = true; *cp != '\0'; cp++) { if (*cp == ' ' || *cp == '\t') { - *cp = 0; - n = 1; + *cp = '\0'; + in_name = false; } - else if (n) + else if (!in_name) { - *pp++ = cp; - n = 0; + search_list_add (&parser->search_list, cp); + in_name = true; } } - /* Null terminate last domain if there are excess. */ - while (*cp != '\0' && *cp != ' ' && *cp != '\t') - cp++; - *cp = '\0'; - *pp++ = 0; - havesearch = true; continue; } /* Read nameservers to query. */ - if (MATCH (*buffer, "nameserver") && nserv < MAXNS) + if (MATCH (parser->buffer, "nameserver") && nserv < MAXNS) { struct in_addr a; - cp = *buffer + sizeof ("nameserver") - 1; + cp = parser->buffer + sizeof ("nameserver") - 1; while (*cp == ' ' || *cp == '\t') cp++; if ((*cp != '\0') && (*cp != '\n') && __inet_aton (cp, &a)) @@ -335,11 +402,11 @@ res_vinit_1 (res_state statp, bool preinit, FILE *fp, char **buffer) } continue; } - if (MATCH (*buffer, "sortlist")) + if (MATCH (parser->buffer, "sortlist")) { struct in_addr a; - cp = *buffer + sizeof ("sortlist") - 1; + cp = parser->buffer + sizeof ("sortlist") - 1; while (nsort < MAXRESOLVSORT) { while (*cp == ' ' || *cp == '\t') @@ -379,9 +446,9 @@ res_vinit_1 (res_state statp, bool preinit, FILE *fp, char **buffer) } continue; } - if (MATCH (*buffer, "options")) + if (MATCH (parser->buffer, "options")) { - res_setoptions (statp, *buffer + sizeof ("options") - 1); + res_setoptions (statp, parser->buffer + sizeof ("options") - 1); continue; } } @@ -399,25 +466,29 @@ res_vinit_1 (res_state statp, bool preinit, FILE *fp, char **buffer) statp->nsaddr.sin_port = htons (NAMESERVER_PORT); statp->nscount = 1; } - if (statp->defdname[0] == 0) - { - char buf[sizeof (statp->defdname)]; - if (__gethostname (buf, sizeof (statp->defdname) - 1) == 0 - && (cp = strchr (buf, '.')) != NULL) - strcpy (statp->defdname, cp + 1); - } - /* Find components of local domain that might be searched. */ - if (!havesearch) + if (search_list_size (&parser->search_list) == 0) { - pp = statp->dnsrch; - *pp++ = statp->defdname; - *pp = NULL; - + char *domain; + if (!domain_from_hostname (&domain)) + return false; + if (domain != NULL) + { + free (parser->search_list_store); + parser->search_list_store = domain; + search_list_add (&parser->search_list, domain); + } } if ((cp = getenv ("RES_OPTIONS")) != NULL) res_setoptions (statp, cp); + + if (search_list_has_failed (&parser->search_list)) + { + __set_errno (ENOMEM); + return false; + } + statp->options |= RES_INIT; return true; } @@ -453,13 +524,17 @@ __res_vinit (res_state statp, int preinit) return -1; } - char *buffer = NULL; - bool ok = res_vinit_1 (statp, preinit, fp, &buffer); - free (buffer); + struct resolv_conf_parser parser; + resolv_conf_parser_init (&parser); + bool ok = res_vinit_1 (statp, preinit, fp, &parser); if (ok) { - struct resolv_conf init = { 0 }; /* No data yet. */ + struct resolv_conf init = + { + .search_list = search_list_begin (&parser.search_list), + .search_list_size = search_list_size (&parser.search_list), + }; struct resolv_conf *conf = __resolv_conf_allocate (&init); if (conf == NULL) ok = false; @@ -469,6 +544,7 @@ __res_vinit (res_state statp, int preinit) __resolv_conf_put (conf); } } + resolv_conf_parser_free (&parser); if (!ok) { |