src/libloc.c

   1 /*
   2         libloc - A library to determine the location of someone on the Internet
   3
   4         Copyright (C) 2017 IPFire Development Team <info@ipfire.org>
   5
   6         This library is free software; you can redistribute it and/or
   7         modify it under the terms of the GNU Lesser General Public
   8         License as published by the Free Software Foundation; either
   9         version 2.1 of the License, or (at your option) any later version.
  10
  11         This library is distributed in the hope that it will be useful,
  12         but WITHOUT ANY WARRANTY; without even the implied warranty of
  13         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14         Lesser General Public License for more details.
  15 */
  16
  17 #include <arpa/inet.h>
  18 #include <netinet/in.h>
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <stddef.h>
  22 #include <stdarg.h>
  23 #include <unistd.h>
  24 #include <errno.h>
  25 #include <string.h>
  26 #include <ctype.h>
  27
  28 #include <loc/libloc.h>
  29 #include <loc/compat.h>
  30 #include <loc/private.h>
  31
  32 struct loc_ctx {
  33         int refcount;
  34         void (*log_fn)(struct loc_ctx* ctx,
  35                 int priority, const char *file, int line, const char *fn,
  36                 const char *format, va_list args);
  37         int log_priority;
  38 };
  39
  40 void loc_log(struct loc_ctx* ctx,
  41                 int priority, const char* file, int line, const char* fn,
  42                 const char* format, ...) {
  43         va_list args;
  44
  45         va_start(args, format);
  46         ctx->log_fn(ctx, priority, file, line, fn, format, args);
  47         va_end(args);
  48 }
  49
  50 static void log_stderr(struct loc_ctx* ctx,
  51                 int priority, const char* file, int line, const char* fn,
  52                 const char* format, va_list args) {
  53         fprintf(stderr, "libloc: %s: ", fn);
  54         vfprintf(stderr, format, args);
  55 }
  56
  57 static int log_priority(const char* priority) {
  58         char *endptr;
  59
  60         int prio = strtol(priority, &endptr, 10);
  61
  62         if (endptr[0] == '\0' || isspace(endptr[0]))
  63                 return prio;
  64
  65         if (strncmp(priority, "err", 3) == 0)
  66                 return LOG_ERR;
  67
  68         if (strncmp(priority, "info", 4) == 0)
  69                 return LOG_INFO;
  70
  71         if (strncmp(priority, "debug", 5) == 0)
  72                 return LOG_DEBUG;
  73
  74         return 0;
  75 }
  76
  77 LOC_EXPORT int loc_new(struct loc_ctx** ctx) {
  78         struct loc_ctx* c = calloc(1, sizeof(*c));
  79         if (!c)
  80                 return -ENOMEM;
  81
  82         c->refcount = 1;
  83         c->log_fn = log_stderr;
  84         c->log_priority = LOG_ERR;
  85
  86         const char* env = secure_getenv("LOC_LOG");
  87         if (env)
  88                 loc_set_log_priority(c, log_priority(env));
  89
  90         INFO(c, "ctx %p created\n", c);
  91         DEBUG(c, "log_priority=%d\n", c->log_priority);
  92         *ctx = c;
  93
  94         return 0;
  95 }
  96
  97 LOC_EXPORT struct loc_ctx* loc_ref(struct loc_ctx* ctx) {
  98         if (!ctx)
  99                 return NULL;
 100
 101         ctx->refcount++;
 102
 103         return ctx;
 104 }
 105
 106 LOC_EXPORT struct loc_ctx* loc_unref(struct loc_ctx* ctx) {
 107         if (!ctx)
 108                 return NULL;
 109
 110         if (--ctx->refcount > 0)
 111                 return NULL;
 112
 113         INFO(ctx, "context %p released\n", ctx);
 114         free(ctx);
 115
 116         return NULL;
 117 }
 118
 119 LOC_EXPORT void loc_set_log_fn(struct loc_ctx* ctx,
 120                 void (*log_fn)(struct loc_ctx* ctx, int priority, const char* file,
 121                 int line, const char* fn, const char* format, va_list args)) {
 122         ctx->log_fn = log_fn;
 123         INFO(ctx, "custom logging function %p registered\n", log_fn);
 124 }
 125
 126 LOC_EXPORT int loc_get_log_priority(struct loc_ctx* ctx) {
 127         return ctx->log_priority;
 128 }
 129
 130 LOC_EXPORT void loc_set_log_priority(struct loc_ctx* ctx, int priority) {
 131         ctx->log_priority = priority;
 132 }
 133
 134 LOC_EXPORT int loc_parse_address(struct loc_ctx* ctx, const char* string, struct in6_addr* address) {
 135         DEBUG(ctx, "Parsing IP address %s\n", string);
 136
 137         // Try parsing this as an IPv6 address
 138         int r = inet_pton(AF_INET6, string, address);
 139
 140         // If inet_pton returns one it has been successful
 141         if (r == 1) {
 142                 DEBUG(ctx, "%s is an IPv6 address\n", string);
 143                 return 0;
 144         }
 145
 146         // Try parsing this as an IPv4 address
 147         struct in_addr ipv4_address;
 148         r = inet_pton(AF_INET, string, &ipv4_address);
 149         if (r == 1) {
 150                 DEBUG(ctx, "%s is an IPv4 address\n", string);
 151
 152                 // Convert to IPv6-mapped address
 153                 address->s6_addr32[0] = htonl(0x0000);
 154                 address->s6_addr32[1] = htonl(0x0000);
 155                 address->s6_addr32[2] = htonl(0xffff);
 156                 address->s6_addr32[3] = ipv4_address.s_addr;
 157
 158                 return 0;
 159         }
 160
 161         DEBUG(ctx, "%s is not an valid IP address\n", string);
 162         return -EINVAL;
 163 }