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Diffstat (limited to 'src/util/inet_prefix_top.c')
| -rw-r--r-- | src/util/inet_prefix_top.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/src/util/inet_prefix_top.c b/src/util/inet_prefix_top.c new file mode 100644 index 0000000..8d5af00 --- /dev/null +++ b/src/util/inet_prefix_top.c @@ -0,0 +1,172 @@ +/*++ +/* NAME +/* inet_prefix_top 3 +/* SUMMARY +/* convert net/mask to printable string +/* SYNOPSIS +/* #include <inet_prefix_top.h> +/* +/* char *inet_prefix_top( +/* int family, +/* const void *src, +/* int prefix_len) +/* DESCRIPTION +/* inet_prefix_top() prints the network portion of the specified +/* IPv4 or IPv6 address, null bits for the host portion, and +/* the prefix length if it is shorter than the address. +/* The result should be passed to myfree(). The code can +/* handle addresses of any length, and bytes of any width. +/* +/* Arguments: +/* .IP af +/* The address family, as with inet_ntop(). +/* .IP src +/* Pointer to storage for an IPv4 or IPv6 address, as with +/* inet_ntop(). +/* .IP prefix_len +/* The number of most-significant bits in \fBsrc\fR that should +/* not be cleared. +/* DIAGNOSTICS +/* Panic: unexpected protocol family, bad prefix length. Fatal +/* errors: address conversion error. +/* LICENSE +/* .ad +/* .fi +/* The Secure Mailer license must be distributed with this software. +/* AUTHOR(S) +/* Wietse Venema +/*--*/ + + /* + * System library. + */ +#include <sys_defs.h> +#include <sys/socket.h> +#include <netinet/in.h> +#include <arpa/inet.h> +#include <string.h> + + /* + * Utility library. + */ +#include <mask_addr.h> +#include <msg.h> +#include <inet_addr_sizes.h> +#include <inet_prefix_top.h> +#include <vstring.h> + +/* inet_prefix_top - printable net/mask pattern */ + +char *inet_prefix_top(int af, const void *src, int prefix_len) +{ + const char myname[] = "inet_prefix_top"; + union { + struct in_addr in_addr; + struct in6_addr in6_addr; + } u; + VSTRING *buf; + const INET_ADDR_SIZES *sp; + + /* + * Sanity checks. XXX We use msg_fatal() because mail_conf_int() does not + * (yet) support non-negative integers. + */ + if ((sp = inet_addr_sizes(af)) == 0) + msg_panic("%s: unexpected address family: %d", myname, af); + if (prefix_len > sp->addr_bitcount || prefix_len < 0) + msg_fatal("%s: bad %s address prefix length: %d", + myname, sp->ipproto_str, prefix_len); + + /* + * Strip a copy of the input address. When allocating the result memory, + * add 1 for the string terminator from inet_ntop(), or 1 for the '/' + * before the prefix. We should not rely on vstring(3)'s safety byte. + */ + memcpy((void *) &u, src, sp->addr_bytecount); + if (prefix_len < sp->addr_bitcount) { + mask_addr((unsigned char *) &u, sp->addr_bytecount, prefix_len); + buf = vstring_alloc(sp->addr_strlen + sp->addr_bitcount_strlen + 1); + } else { + buf = vstring_alloc(sp->addr_strlen + 1); + } + + /* + * Convert the result to string, and append the optional /prefix. + */ + if (inet_ntop(af, &u, vstring_str(buf), vstring_avail(buf)) == 0) + msg_fatal("%s: inet_ntop: %m", myname); + vstring_set_payload_size(buf, strlen(vstring_str(buf))); + if (prefix_len < sp->addr_bitcount) + vstring_sprintf_append(buf, "/%d", prefix_len); + return (vstring_export(buf)); +} + +#ifdef TEST + +#include <stdlib.h> +#include <msg_vstream.h> +#include <name_code.h> + + /* + * TODO: add test cases for fatal and panic errors, intercept msg_fatal() + * and msg_panic(), and verify the expected error messages. + */ +typedef struct TEST_CASE { + int in_af; + int in_prefix_len; + const char *exp_prefix; +} TEST_CASE; + +static TEST_CASE test_cases[] = { + AF_INET, 32, "255.255.255.255", + AF_INET, 28, "255.255.255.240/28", + AF_INET, 4, "240.0.0.0/4", + AF_INET, 0, "0.0.0.0/0", + AF_INET6, 128, "ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff", + AF_INET6, 124, "ffff:ffff:ffff:ffff:ffff:ffff:ffff:fff0/124", + AF_INET6, 4, "f000::/4", + AF_INET6, 0, "::/0", +}; + +const NAME_CODE af_map[] = { + "AF_INET", AF_INET, + "AF_INET6", AF_INET6, + 0, +}; + +#define TEST_CASE_COUNT (sizeof(test_cases) / sizeof(test_cases[0])) + +int main(int argc, char **argv) +{ + TEST_CASE *tp; + union { + struct in_addr in_addr; + struct in6_addr in6_addr; + } u; + char *act_prefix; + int pass = 0; + int fail = 0; + + msg_vstream_init(argv[0], VSTREAM_ERR); + memset(&u, ~0, sizeof(u)); + + for (tp = test_cases; tp < test_cases + TEST_CASE_COUNT; tp++) { + msg_info("RUN %s/%d", str_name_code(af_map, tp->in_af), + tp->in_prefix_len); + act_prefix = inet_prefix_top(tp->in_af, &u, tp->in_prefix_len); + if (strcmp(act_prefix, tp->exp_prefix) != 0) { + msg_warn("got \"%s\", want \"%s\"", act_prefix, tp->exp_prefix); + fail += 1; + msg_info("FAIL %s/%d", str_name_code(af_map, tp->in_af), + tp->in_prefix_len); + } else { + pass += 1; + msg_info("PASS %s/%d", str_name_code(af_map, tp->in_af), + tp->in_prefix_len); + } + } + msg_info("PASS=%d FAIL=%d", pass, fail); + return (fail > 0); +} + +#endif /* TEST */ |