diff options
Diffstat (limited to 'src/c-ares/ares__get_hostent.c')
| -rw-r--r-- | src/c-ares/ares__get_hostent.c | 261 |
1 files changed, 261 insertions, 0 deletions
diff --git a/src/c-ares/ares__get_hostent.c b/src/c-ares/ares__get_hostent.c new file mode 100644 index 000000000..d2f950349 --- /dev/null +++ b/src/c-ares/ares__get_hostent.c @@ -0,0 +1,261 @@ + +/* Copyright 1998, 2011 by the Massachusetts Institute of Technology. + * + * Permission to use, copy, modify, and distribute this + * software and its documentation for any purpose and without + * fee is hereby granted, provided that the above copyright + * notice appear in all copies and that both that copyright + * notice and this permission notice appear in supporting + * documentation, and that the name of M.I.T. not be used in + * advertising or publicity pertaining to distribution of the + * software without specific, written prior permission. + * M.I.T. makes no representations about the suitability of + * this software for any purpose. It is provided "as is" + * without express or implied warranty. + */ + +#include "ares_setup.h" + +#ifdef HAVE_NETINET_IN_H +# include <netinet/in.h> +#endif +#ifdef HAVE_NETDB_H +# include <netdb.h> +#endif +#ifdef HAVE_ARPA_INET_H +# include <arpa/inet.h> +#endif + +#include "ares.h" +#include "ares_inet_net_pton.h" +#include "ares_nowarn.h" +#include "ares_private.h" + +int ares__get_hostent(FILE *fp, int family, struct hostent **host) +{ + char *line = NULL, *p, *q, **alias; + char *txtaddr, *txthost, *txtalias; + int status; + size_t addrlen, linesize, naliases; + struct ares_addr addr; + struct hostent *hostent = NULL; + + *host = NULL; /* Assume failure */ + + /* Validate family */ + switch (family) { + case AF_INET: + case AF_INET6: + case AF_UNSPEC: + break; + default: + return ARES_EBADFAMILY; + } + + while ((status = ares__read_line(fp, &line, &linesize)) == ARES_SUCCESS) + { + + /* Trim line comment. */ + p = line; + while (*p && (*p != '#')) + p++; + *p = '\0'; + + /* Trim trailing whitespace. */ + q = p - 1; + while ((q >= line) && ISSPACE(*q)) + q--; + *++q = '\0'; + + /* Skip leading whitespace. */ + p = line; + while (*p && ISSPACE(*p)) + p++; + if (!*p) + /* Ignore line if empty. */ + continue; + + /* Pointer to start of IPv4 or IPv6 address part. */ + txtaddr = p; + + /* Advance past address part. */ + while (*p && !ISSPACE(*p)) + p++; + if (!*p) + /* Ignore line if reached end of line. */ + continue; + + /* Null terminate address part. */ + *p = '\0'; + + /* Advance to host name */ + p++; + while (*p && ISSPACE(*p)) + p++; + if (!*p) + /* Ignore line if reached end of line. */ + continue; /* LCOV_EXCL_LINE: trailing whitespace already stripped */ + + /* Pointer to start of host name. */ + txthost = p; + + /* Advance past host name. */ + while (*p && !ISSPACE(*p)) + p++; + + /* Pointer to start of first alias. */ + txtalias = NULL; + if (*p) + { + q = p + 1; + while (*q && ISSPACE(*q)) + q++; + if (*q) + txtalias = q; + } + + /* Null terminate host name. */ + *p = '\0'; + + /* find out number of aliases. */ + naliases = 0; + if (txtalias) + { + p = txtalias; + while (*p) + { + while (*p && !ISSPACE(*p)) + p++; + while (*p && ISSPACE(*p)) + p++; + naliases++; + } + } + + /* Convert address string to network address for the requested family. */ + addrlen = 0; + addr.family = AF_UNSPEC; + addr.addrV4.s_addr = INADDR_NONE; + if ((family == AF_INET) || (family == AF_UNSPEC)) + { + addr.addrV4.s_addr = inet_addr(txtaddr); + if (addr.addrV4.s_addr != INADDR_NONE) + { + /* Actual network address family and length. */ + addr.family = AF_INET; + addrlen = sizeof(addr.addrV4); + } + } + if ((family == AF_INET6) || ((family == AF_UNSPEC) && (!addrlen))) + { + if (ares_inet_pton(AF_INET6, txtaddr, &addr.addrV6) > 0) + { + /* Actual network address family and length. */ + addr.family = AF_INET6; + addrlen = sizeof(addr.addrV6); + } + } + if (!addrlen) + /* Ignore line if invalid address string for the requested family. */ + continue; + + /* + ** Actual address family possible values are AF_INET and AF_INET6 only. + */ + + /* Allocate memory for the hostent structure. */ + hostent = ares_malloc(sizeof(struct hostent)); + if (!hostent) + break; + + /* Initialize fields for out of memory condition. */ + hostent->h_aliases = NULL; + hostent->h_addr_list = NULL; + + /* Copy official host name. */ + hostent->h_name = ares_strdup(txthost); + if (!hostent->h_name) + break; + + /* Copy network address. */ + hostent->h_addr_list = ares_malloc(2 * sizeof(char *)); + if (!hostent->h_addr_list) + break; + hostent->h_addr_list[1] = NULL; + hostent->h_addr_list[0] = ares_malloc(addrlen); + if (!hostent->h_addr_list[0]) + break; + if (addr.family == AF_INET) + memcpy(hostent->h_addr_list[0], &addr.addrV4, sizeof(addr.addrV4)); + else + memcpy(hostent->h_addr_list[0], &addr.addrV6, sizeof(addr.addrV6)); + + /* Copy aliases. */ + hostent->h_aliases = ares_malloc((naliases + 1) * sizeof(char *)); + if (!hostent->h_aliases) + break; + alias = hostent->h_aliases; + while (naliases) + *(alias + naliases--) = NULL; + *alias = NULL; + while (txtalias) + { + p = txtalias; + while (*p && !ISSPACE(*p)) + p++; + q = p; + while (*q && ISSPACE(*q)) + q++; + *p = '\0'; + if ((*alias = ares_strdup(txtalias)) == NULL) + break; + alias++; + txtalias = *q ? q : NULL; + } + if (txtalias) + /* Alias memory allocation failure. */ + break; + + /* Copy actual network address family and length. */ + hostent->h_addrtype = aresx_sitoss(addr.family); + hostent->h_length = aresx_uztoss(addrlen); + + /* Free line buffer. */ + ares_free(line); + + /* Return hostent successfully */ + *host = hostent; + return ARES_SUCCESS; + + } + + /* If allocated, free line buffer. */ + if (line) + ares_free(line); + + if (status == ARES_SUCCESS) + { + /* Memory allocation failure; clean up. */ + if (hostent) + { + if (hostent->h_name) + ares_free((char *) hostent->h_name); + if (hostent->h_aliases) + { + for (alias = hostent->h_aliases; *alias; alias++) + ares_free(*alias); + ares_free(hostent->h_aliases); + } + if (hostent->h_addr_list) + { + if (hostent->h_addr_list[0]) + ares_free(hostent->h_addr_list[0]); + ares_free(hostent->h_addr_list); + } + ares_free(hostent); + } + return ARES_ENOMEM; + } + + return status; +} |