diff options
| -rw-r--r-- | main.c | 42 |
1 files changed, 27 insertions, 15 deletions
@@ -1,5 +1,6 @@ #include <u.h> #include <libc.h> +#include <ctype.h> typedef struct IPNet IPNet; @@ -61,6 +62,26 @@ countones(u32int addr) return cnt; } +u32int +getip4(char *s) +{ + u32int addr; + int octets; + + addr = 0; + octets = 4; + + do{ + if(!isdigit(*s)) + sysfatal("wrong ip address: expected a number"); + addr |= strtoul(s, &s, 10) << --octets*8; + if(octets > 0 && *s != '.') + sysfatal("wrong ip address: expected a dot"); + }while(*s++ && octets > 0); + + return addr; +} + void usage(void) { @@ -73,7 +94,6 @@ main(int argc, char *argv[]) { IPNet net; u32int addr, mask; - char *a, *m; int cidr; fmtinstall('I', Ifmt); @@ -84,21 +104,13 @@ main(int argc, char *argv[]) if(argc != 2) usage(); - a = argv[0]; - addr = strtoul(a, &a, 10) << 24; - addr |= strtoul(++a, &a, 10) << 16; - addr |= strtoul(++a, &a, 10) << 8; - addr |= strtoul(++a, &a, 10); - m = argv[1]; - if(strlen(m) <= 2){ - cidr = strtol(m, nil, 10); + addr = getip4(argv[0]); + if(strlen(argv[1]) <= 2){ + cidr = strtol(argv[1], nil, 10); + assert(cidr > 0 && cidr <= 32); mask = ~0 << (32-cidr); - }else{ - mask = strtoul(m, &m, 10) << 24; - mask |= strtoul(++m, &m, 10) << 16; - mask |= strtoul(++m, &m, 10) << 8; - mask |= strtoul(++m, &m, 10); - } + }else + mask = getip4(argv[1]); net.addr = addr&mask; net.mask = mask; |