diff options
Diffstat (limited to 'networking/nslookup.c')
| -rw-r--r-- | networking/nslookup.c | 185 |
1 files changed, 87 insertions, 98 deletions
diff --git a/networking/nslookup.c b/networking/nslookup.c index 969d0b1..ffa7201 100644 --- a/networking/nslookup.c +++ b/networking/nslookup.c @@ -1,3 +1,4 @@ +/* vi: set sw=4 ts=4: */ /* * Mini nslookup implementation for busybox * @@ -41,148 +42,136 @@ | + find out how the real nslookup gets the default name server */ -static const char nslookup_usage[] = - "nslookup [HOST]\n\n" -; +static const char nslookup_usage[] = "nslookup [HOST]\n\n"; /* I have to see how the real nslookup does this. * I could dig through /etc/resolv.conf, but is there a * better (programatic) way? */ -static void -server_fprint(FILE *dst) +static void server_fprint(FILE * dst) { - fprintf(dst, "Server: %s\n", "something"); - fprintf(dst, "Address: %s\n\n", "something"); + fprintf(dst, "Server: %s\n", "something"); + fprintf(dst, "Address: %s\n\n", "something"); } /* only works for IPv4 */ -static int -addr_fprint(char *addr, FILE *dst) +static int addr_fprint(char *addr, FILE * dst) { - uint8_t split[4]; - uint32_t ip; - uint32_t *x = (uint32_t *) addr; - - ip = ntohl(*x); - split[0] = (ip & 0xff000000) >> 24; - split[1] = (ip & 0x00ff0000) >> 16; - split[2] = (ip & 0x0000ff00) >> 8; - split[3] = (ip & 0x000000ff); - fprintf ( - dst, "%d.%d.%d.%d", - split[0], split[1], split[2], split[3] - ); - return 0; + uint8_t split[4]; + uint32_t ip; + uint32_t *x = (uint32_t *) addr; + + ip = ntohl(*x); + split[0] = (ip & 0xff000000) >> 24; + split[1] = (ip & 0x00ff0000) >> 16; + split[2] = (ip & 0x0000ff00) >> 8; + split[3] = (ip & 0x000000ff); + fprintf(dst, "%d.%d.%d.%d", split[0], split[1], split[2], split[3] + ); + return 0; } /* changes a c-string matching the perl regex \d+\.\d+\.\d+\.\d+ * into a uint32_t */ -static uint32_t -str_to_addr(const char *addr) +static uint32_t str_to_addr(const char *addr) { - uint32_t split[4]; - uint32_t ip; + uint32_t split[4]; + uint32_t ip; - sscanf(addr, "%d.%d.%d.%d", - &split[0], &split[1], &split[2], &split[3]); + sscanf(addr, "%d.%d.%d.%d", + &split[0], &split[1], &split[2], &split[3]); - /* assuming sscanf worked */ - ip = (split[0] << 24) | - (split[1] << 16) | - (split[2] << 8) | - (split[3]); + /* assuming sscanf worked */ + ip = (split[0] << 24) | + (split[1] << 16) | (split[2] << 8) | (split[3]); - return htonl(ip); + return htonl(ip); } /* takes the NULL-terminated array h_addr_list, and * prints its contents appropriately */ -static int -addr_list_fprint(char **h_addr_list, FILE *dst) +static int addr_list_fprint(char **h_addr_list, FILE * dst) { - int i, j; - char *addr_string = (h_addr_list[1]) - ? "Addresses" - : "Address"; - - fprintf(dst, "%s: ", addr_string); - for (i = 0, j = 0; h_addr_list[i]; i++, j++) { - addr_fprint(h_addr_list[i], dst); - - /* real nslookup does this */ - if (j == 4) { - if (h_addr_list[i+1]) { - fprintf(dst, "\n "); - } - j = 0; - } else { - if (h_addr_list[i+1]) { - fprintf(dst, ", "); - } - } + int i, j; + char *addr_string = (h_addr_list[1]) + ? "Addresses" : "Address"; + + fprintf(dst, "%s: ", addr_string); + for (i = 0, j = 0; h_addr_list[i]; i++, j++) { + addr_fprint(h_addr_list[i], dst); + + /* real nslookup does this */ + if (j == 4) { + if (h_addr_list[i + 1]) { + fprintf(dst, "\n "); + } + j = 0; + } else { + if (h_addr_list[i + 1]) { + fprintf(dst, ", "); + } + } - } - fprintf(dst,"\n"); - return 0; + } + fprintf(dst, "\n"); + return 0; } /* gethostbyaddr wrapper */ -static struct hostent * -gethostbyaddr_wrapper(const char *address) +static struct hostent *gethostbyaddr_wrapper(const char *address) { - struct in_addr addr; + struct in_addr addr; - addr.s_addr = str_to_addr(address); - return gethostbyaddr((char *) &addr, 4, AF_INET); /* IPv4 only for now */ + addr.s_addr = str_to_addr(address); + return gethostbyaddr((char *) &addr, 4, AF_INET); /* IPv4 only for now */ } /* print the results as nslookup would */ -static struct hostent * -hostent_fprint(struct hostent *host, FILE *dst) +static struct hostent *hostent_fprint(struct hostent *host, FILE * dst) { - if (host) { - fprintf(dst, "Name: %s\n", host->h_name); - addr_list_fprint(host->h_addr_list, dst); - } else { - fprintf(dst, "*** %s\n", hstrerror(h_errno)); - } - return host; + if (host) { + fprintf(dst, "Name: %s\n", host->h_name); + addr_list_fprint(host->h_addr_list, dst); + } else { + fprintf(dst, "*** %s\n", hstrerror(h_errno)); + } + return host; } /* naive function to check whether char *s is an ip address */ -static int -is_ip_address(const char *s) +static int is_ip_address(const char *s) { - while (*s) { - if ((isdigit(*s)) || (*s == '.')) { s++; continue; } - return 0; - } - return 1; + while (*s) { + if ((isdigit(*s)) || (*s == '.')) { + s++; + continue; + } + return 0; + } + return 1; } /* ________________________________________________________________________ */ -int -nslookup_main(int argc, char **argv) +int nslookup_main(int argc, char **argv) { - struct hostent *host; - - if (argc < 2) { - usage(nslookup_usage); - } - - server_fprint(stdout); - if (is_ip_address(argv[1])) { - host = gethostbyaddr_wrapper(argv[1]); - } else { - host = gethostbyname(argv[1]); - } - hostent_fprint(host, stdout); - return 0; + struct hostent *host; + + if (argc < 2) { + usage(nslookup_usage); + } + + server_fprint(stdout); + if (is_ip_address(argv[1])) { + host = gethostbyaddr_wrapper(argv[1]); + } else { + host = gethostbyname(argv[1]); + } + hostent_fprint(host, stdout); + return 0; } -/* $Id: nslookup.c,v 1.3 2000/02/07 05:29:42 erik Exp $ */ +/* $Id: nslookup.c,v 1.4 2000/02/08 19:58:47 erik Exp $ */ |