ref: 4d96bacd35e6afcf86e1791b0747ef752951b014
dir: /sys/src/libip/parseip.c/
#include <u.h> #include <libc.h> #include <ctype.h> #include <ip.h> char* v4parseip(uchar *to, char *from) { int i; char *p; p = from; for(i = 0; i < 4 && *p; i++){ to[i] = strtoul(p, &p, 0); if(*p == '.') p++; } switch(CLASS(to)){ case 0: /* class A - 1 uchar net */ case 1: if(i == 3){ to[3] = to[2]; to[2] = to[1]; to[1] = 0; } else if (i == 2){ to[3] = to[1]; to[1] = 0; } break; case 2: /* class B - 2 uchar net */ if(i == 3){ to[3] = to[2]; to[2] = 0; } break; } return p; } static int ipcharok(int c) { return c == '.' || c == ':' || isascii(c) && isxdigit(c); } static int delimchar(int c) { if(c == '\0') return 1; if(c == '.' || c == ':' || isascii(c) && isalnum(c)) return 0; return 1; } /* * `from' may contain an address followed by other characters, * at least in /boot, so we permit whitespace (and more) after the address. * we do ensure that "delete" cannot be parsed as "de::". * * some callers don't check the return value for errors, so * set `to' to something distinctive in the case of a parse error. */ vlong parseip(uchar *to, char *from) { int i, elipsis = 0, v4 = 1; ulong x; char *p, *op; memset(to, 0, IPaddrlen); p = from; for(i = 0; i < IPaddrlen && ipcharok(*p); i+=2){ op = p; x = strtoul(p, &p, 16); if(*p == '.' || (*p == 0 && i == 0)){ /* ends with v4? */ if(i > IPaddrlen-4){ memset(to, 0, IPaddrlen); return -1; /* parse error */ } p = v4parseip(to+i, op); i += 4; break; } /* v6: at most 4 hex digits, followed by colon or delim */ if(x != (ushort)x || *p != ':' && !delimchar(*p)) { memset(to, 0, IPaddrlen); return -1; /* parse error */ } to[i] = x>>8; to[i+1] = x; if(*p == ':'){ v4 = 0; if(*++p == ':'){ /* :: is elided zero short(s) */ if (elipsis) { memset(to, 0, IPaddrlen); return -1; /* second :: */ } elipsis = i+2; p++; } } else if (p == op) /* strtoul made no progress? */ break; } if (p == from || !delimchar(*p)) { memset(to, 0, IPaddrlen); return -1; /* parse error */ } if(i < IPaddrlen){ memmove(&to[elipsis+IPaddrlen-i], &to[elipsis], i-elipsis); memset(&to[elipsis], 0, IPaddrlen-i); } if(v4){ to[10] = to[11] = 0xff; return (ulong)nhgetl(to + IPv4off); } else return 6; } /* * hack to allow ip v4 masks to be entered in the old * style */ vlong parseipmask(uchar *to, char *from, int v4) { vlong x; int i, w; uchar *p; if(*from == '/'){ /* as a number of prefix bits */ i = atoi(from+1); if(i < 0) i = 0; if(i <= 32 && v4) i += 96; if(i > 128) i = 128; w = i; memset(to, 0, IPaddrlen); for(p = to; i >= 8; i -= 8) *p++ = 0xff; if(i > 0) *p = ~((1<<(8-i))-1); /* * identify as ipv6 if the mask is inexpressible as a v4 mask * (because it has too few mask bits). Arguably, we could * always return 6 here. */ if (w < 96) return v4 ? -1 : 6; x = (ulong)nhgetl(to+IPv4off); } else { /* as a straight v4 bit mask */ x = parseip(to, from); if(memcmp(to, v4prefix, IPv4off) == 0) memset(to, 0xff, IPv4off); else if(v4 && memcmp(to, IPallbits, IPv4off) != 0) x = -1; } return x; } vlong parseipandmask(uchar *ip, uchar *mask, char *ipstr, char *maskstr) { vlong x; x = parseip(ip, ipstr); if(maskstr == nil) memset(mask, 0xff, IPaddrlen); else if(parseipmask(mask, maskstr, memcmp(ip, v4prefix, IPv4off) == 0) == -1) x = -1; return x; }