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Diffstat (limited to 'src/libfreeswan/rangetosubnet.c')
| -rw-r--r-- | src/libfreeswan/rangetosubnet.c | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/src/libfreeswan/rangetosubnet.c b/src/libfreeswan/rangetosubnet.c new file mode 100644 index 000000000..048b10556 --- /dev/null +++ b/src/libfreeswan/rangetosubnet.c @@ -0,0 +1,226 @@ +/* + * express an address range as a subnet (if possible) + * Copyright (C) 2000 Henry Spencer. + * + * This library is free software; you can redistribute it and/or modify it + * under the terms of the GNU Library General Public License as published by + * the Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. See <http://www.fsf.org/copyleft/lgpl.txt>. + * + * This library is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public + * License for more details. + * + * RCSID $Id: rangetosubnet.c,v 1.1 2004/03/15 20:35:26 as Exp $ + */ +#include "internal.h" +#include "freeswan.h" + +/* + - rangetosubnet - turn an address range into a subnet, if possible + * + * A range which is a valid subnet will have a network part which is the + * same in the from value and the to value, followed by a host part which + * is all 0 in the from value and all 1 in the to value. + */ +err_t +rangetosubnet(from, to, dst) +const ip_address *from; +const ip_address *to; +ip_subnet *dst; +{ + unsigned const char *fp; + unsigned const char *tp; + unsigned fb; + unsigned tb; + unsigned const char *f; + unsigned const char *t; + size_t n; + size_t n2; + int i; + int nnet; + unsigned m; + + if (addrtypeof(from) != addrtypeof(to)) + return "mismatched address types"; + n = addrbytesptr(from, &fp); + if (n == 0) + return "unknown address type"; + n2 = addrbytesptr(to, &tp); + if (n != n2) + return "internal size mismatch in rangetosubnet"; + + f = fp; + t = tp; + nnet = 0; + for (i = n; i > 0 && *f == *t; i--, f++, t++) + nnet += 8; + if (i > 0 && !(*f == 0x00 && *t == 0xff)) { /* mid-byte bdry. */ + fb = *f++; + tb = *t++; + i--; + m = 0x80; + while ((fb&m) == (tb&m)) { + fb &= ~m; + tb |= m; + m >>= 1; + nnet++; + } + if (fb != 0x00 || tb != 0xff) + return "not a valid subnet"; + } + for (; i > 0 && *f == 0x00 && *t == 0xff; i--, f++, t++) + continue; + + if (i != 0) + return "invalid subnet"; + + return initsubnet(from, nnet, 'x', dst); +} + + + +#ifdef RANGETOSUBNET_MAIN + +#include <stdio.h> + +void regress(void); + +int +main(int argc, char *argv[]) +{ + ip_address start; + ip_address stop; + ip_subnet sub; + char buf[100]; + const char *oops; + size_t n; + int af; + int i; + + if (argc == 2 && strcmp(argv[1], "-r") == 0) { + regress(); + fprintf(stderr, "regress() returned?!?\n"); + exit(1); + } + + if (argc < 3) { + fprintf(stderr, "Usage: %s [-6] start stop\n", argv[0]); + fprintf(stderr, " or: %s -r\n", argv[0]); + exit(2); + } + + af = AF_INET; + i = 1; + if (strcmp(argv[i], "-6") == 0) { + af = AF_INET6; + i++; + } + + oops = ttoaddr(argv[i], 0, af, &start); + if (oops != NULL) { + fprintf(stderr, "%s: start conversion failed: %s\n", argv[0], oops); + exit(1); + } + oops = ttoaddr(argv[i+1], 0, af, &stop); + if (oops != NULL) { + fprintf(stderr, "%s: stop conversion failed: %s\n", argv[0], oops); + exit(1); + } + oops = rangetosubnet(&start, &stop, &sub); + if (oops != NULL) { + fprintf(stderr, "%s: rangetosubnet failed: %s\n", argv[0], oops); + exit(1); + } + n = subnettot(&sub, 0, buf, sizeof(buf)); + if (n > sizeof(buf)) { + fprintf(stderr, "%s: reverse conversion", argv[0]); + fprintf(stderr, " failed: need %ld bytes, have only %ld\n", + (long)n, (long)sizeof(buf)); + exit(1); + } + printf("%s\n", buf); + + exit(0); +} + +struct rtab { + int family; + char *start; + char *stop; + char *output; /* NULL means error expected */ +} rtab[] = { + {4, "1.2.3.0", "1.2.3.255", "1.2.3.0/24"}, + {4, "1.2.3.0", "1.2.3.7", "1.2.3.0/29"}, + {4, "1.2.3.240", "1.2.3.255", "1.2.3.240/28"}, + {4, "0.0.0.0", "255.255.255.255", "0.0.0.0/0"}, + {4, "1.2.3.4", "1.2.3.4", "1.2.3.4/32"}, + {4, "1.2.3.0", "1.2.3.254", NULL}, + {4, "1.2.3.0", "1.2.3.126", NULL}, + {4, "1.2.3.0", "1.2.3.125", NULL}, + {4, "1.2.0.0", "1.2.255.255", "1.2.0.0/16"}, + {4, "1.2.0.0", "1.2.0.255", "1.2.0.0/24"}, + {4, "1.2.255.0", "1.2.255.255", "1.2.255.0/24"}, + {4, "1.2.255.0", "1.2.254.255", NULL}, + {4, "1.2.255.1", "1.2.255.255", NULL}, + {4, "1.2.0.1", "1.2.255.255", NULL}, + {6, "1:2:3:4:5:6:7:0", "1:2:3:4:5:6:7:ffff", "1:2:3:4:5:6:7:0/112"}, + {6, "1:2:3:4:5:6:7:0", "1:2:3:4:5:6:7:fff", "1:2:3:4:5:6:7:0/116"}, + {6, "1:2:3:4:5:6:7:f0", "1:2:3:4:5:6:7:ff", "1:2:3:4:5:6:7:f0/124"}, + {4, NULL, NULL, NULL}, +}; + +void +regress() +{ + struct rtab *r; + int status = 0; + ip_address start; + ip_address stop; + ip_subnet sub; + char buf[100]; + const char *oops; + size_t n; + int af; + + for (r = rtab; r->start != NULL; r++) { + af = (r->family == 4) ? AF_INET : AF_INET6; + oops = ttoaddr(r->start, 0, af, &start); + if (oops != NULL) { + printf("surprise failure converting `%s'\n", r->start); + exit(1); + } + oops = ttoaddr(r->stop, 0, af, &stop); + if (oops != NULL) { + printf("surprise failure converting `%s'\n", r->stop); + exit(1); + } + oops = rangetosubnet(&start, &stop, &sub); + if (oops != NULL && r->output == NULL) + {} /* okay, error expected */ + else if (oops != NULL) { + printf("`%s'-`%s' rangetosubnet failed: %s\n", + r->start, r->stop, oops); + status = 1; + } else if (r->output == NULL) { + printf("`%s'-`%s' rangetosubnet succeeded unexpectedly\n", + r->start, r->stop); + status = 1; + } else { + n = subnettot(&sub, 0, buf, sizeof(buf)); + if (n > sizeof(buf)) { + printf("`%s'-`%s' subnettot failed: need %ld\n", + r->start, r->stop, (long)n); + status = 1; + } else if (strcmp(r->output, buf) != 0) { + printf("`%s'-`%s' gave `%s', expected `%s'\n", + r->start, r->stop, buf, r->output); + status = 1; + } + } + } + exit(status); +} + +#endif /* RANGETOSUBNET_MAIN */ |