tprintf.c

   1 /*
   2  * netsniff-ng - the packet sniffing beast
   3  * By Daniel Borkmann <daniel@netsniff-ng.org>
   4  * Copyright 2009, 2010 Daniel Borkmann.
   5  * Copyright 2013 Tobias Klauser.
   6  * Subject to the GPL, version 2.
   7  */
   8
   9 #define _BSD_SOURCE
  10 #include <ctype.h>
  11 #include <stdio.h>
  12 #include <stdarg.h>
  13
  14 #include "xutils.h"
  15 #include "tprintf.h"
  16 #include "die.h"
  17 #include "locking.h"
  18 #include "built_in.h"
  19
  20 #define term_trailing_size      5
  21 #define term_starting_size      3
  22
  23 #define term_curr_size          (get_tty_size() - term_trailing_size)
  24
  25 static char buffer[1024];
  26
  27 static volatile size_t buffer_use = 0;
  28
  29 static struct spinlock buffer_lock;
  30
  31 static inline void __tprintf_flush_newline(void)
  32 {
  33         int i;
  34
  35         fputc('\n', stdout);
  36         for (i = 0; i < term_starting_size; ++i)
  37                 fputc(' ', stdout);
  38 }
  39
  40 static inline int __tprintf_flush_skip(char *buffer, int i, size_t max)
  41 {
  42         int val = buffer[i];
  43
  44         if (val == ' ' || val == ',')
  45                 return 1;
  46
  47         return 0;
  48 }
  49
  50 static void __tprintf_flush(void)
  51 {
  52         int i;
  53         static ssize_t line_count = 0;
  54         size_t term_len = term_curr_size;
  55
  56         for (i = 0; i < buffer_use; ++i) {
  57                 if (buffer[i] == '\n') {
  58                         term_len = term_curr_size;
  59                         line_count = -1;
  60                 }
  61
  62                 if (line_count == term_len) {
  63                         __tprintf_flush_newline();
  64                         line_count = term_starting_size;
  65
  66                         while (i < buffer_use &&
  67                                __tprintf_flush_skip(buffer, i, buffer_use))
  68                                 i++;
  69                 }
  70
  71                 fputc(buffer[i], stdout);
  72                 line_count++;
  73         }
  74
  75         fflush(stdout);
  76         buffer_use = 0;
  77 }
  78
  79 void tprintf_flush(void)
  80 {
  81         spinlock_lock(&buffer_lock);
  82         __tprintf_flush();
  83         spinlock_unlock(&buffer_lock);
  84 }
  85
  86 void tprintf_init(void)
  87 {
  88         spinlock_init(&buffer_lock);
  89
  90         setvbuf(stdout, NULL, _IONBF, 0);
  91         setvbuf(stderr, NULL, _IONBF, 0);
  92 }
  93
  94 void tprintf_cleanup(void)
  95 {
  96         tprintf_flush();
  97         spinlock_destroy(&buffer_lock);
  98 }
  99
 100 void tprintf(char *msg, ...)
 101 {
 102         ssize_t ret;
 103         ssize_t avail;
 104         va_list vl;
 105
 106         spinlock_lock(&buffer_lock);
 107
 108         avail = sizeof(buffer) - buffer_use;
 109         bug_on(avail < 0);
 110
 111         va_start(vl, msg);
 112         ret = vsnprintf(buffer + buffer_use, avail, msg, vl);
 113         va_end(vl);
 114
 115         if (ret < 0)
 116                 panic("vsnprintf screwed up in tprintf!\n");
 117         if (ret > sizeof(buffer))
 118                 panic("No mem in tprintf left!\n");
 119         if (ret >= avail) {
 120                 __tprintf_flush();
 121
 122                 avail = sizeof(buffer) - buffer_use;
 123                 bug_on(avail < 0);
 124
 125                 va_start(vl, msg);
 126                 ret = vsnprintf(buffer + buffer_use, avail, msg, vl);
 127                 va_end(vl);
 128
 129                 if (ret < 0)
 130                         panic("vsnprintf screwed up in tprintf!\n");
 131         }
 132
 133         buffer_use += ret;
 134
 135         spinlock_unlock(&buffer_lock);
 136 }
 137
 138 void tputchar_safe(int c)
 139 {
 140         unsigned char ch = (unsigned char)(c & 0xff);
 141
 142         if (isprint(ch))
 143                 tprintf("%c", ch);
 144         else
 145                 tprintf("\\0x%02x", ch);
 146 }
 147
 148 void tputs_safe(const char *str, size_t len)
 149 {
 150         while (len--) {
 151                 tputchar_safe(*str);
 152                 str++;
 153         }
 154 }