/* * BIRD Library -- Formatted Output * * (c) 1991, 1992 Lars Wirzenius & Linus Torvalds * * Hacked up for BIRD by Martin Mares <mj@ucw.cz> * Buffer size limitation implemented by Martin Mares. */ #include "nest/bird.h" #include "string.h" #include <errno.h> /* we use this so that we can do without the ctype library */ #define is_digit(c) ((c) >= '0' && (c) <= '9') static int skip_atoi(const char **s) { int i=0; while (is_digit(**s)) i = i*10 + *((*s)++) - '0'; return i; } #define ZEROPAD 1 /* pad with zero */ #define SIGN 2 /* unsigned/signed long */ #define PLUS 4 /* show plus */ #define SPACE 8 /* space if plus */ #define LEFT 16 /* left justified */ #define SPECIAL 32 /* 0x */ #define LARGE 64 /* use 'ABCDEF' instead of 'abcdef' */ #define do_div(n,base) ({ \ int __res; \ __res = ((unsigned long) n) % (unsigned) base; \ n = ((unsigned long) n) / (unsigned) base; \ __res; }) static char * number(char * str, long num, int base, int size, int precision, int type, int remains) { char c,sign,tmp[66]; const char *digits="0123456789abcdefghijklmnopqrstuvwxyz"; int i; if (size >= 0 && (remains -= size) < 0) return NULL; if (type & LARGE) digits = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"; if (type & LEFT) type &= ~ZEROPAD; if (base < 2 || base > 36) return 0; c = (type & ZEROPAD) ? '0' : ' '; sign = 0; if (type & SIGN) { if (num < 0) { sign = '-'; num = -num; size--; } else if (type & PLUS) { sign = '+'; size--; } else if (type & SPACE) { sign = ' '; size--; } } if (type & SPECIAL) { if (base == 16) size -= 2; else if (base == 8) size--; } i = 0; if (num == 0) tmp[i++]='0'; else while (num != 0) tmp[i++] = digits[do_div(num,base)]; if (i > precision) precision = i; size -= precision; if (size < 0 && -size > remains) return NULL; if (!(type&(ZEROPAD+LEFT))) while(size-->0) *str++ = ' '; if (sign) *str++ = sign; if (type & SPECIAL) { if (base==8) *str++ = '0'; else if (base==16) { *str++ = '0'; *str++ = digits[33]; } } if (!(type & LEFT)) while (size-- > 0) *str++ = c; while (i < precision--) *str++ = '0'; while (i-- > 0) *str++ = tmp[i]; while (size-- > 0) *str++ = ' '; return str; } /** * bvsnprintf - BIRD's vsnprintf() * @buf: destination buffer * @size: size of the buffer * @fmt: format string * @args: a list of arguments to be formatted * * This functions acts like ordinary sprintf() except that it checks * available space to avoid buffer overflows and it allows some more * format specifiers: |%I| for formatting of IP addresses (any non-zero * width is automatically replaced by standard IP address width which * depends on whether we use IPv4 or IPv6; |%#I| gives hexadecimal format) * and |%m| resp. |%M| for error messages (uses strerror() to translate @errno code to * message text). On the other hand, it doesn't support floating * point numbers. * * Result: number of characters of the output string or -1 if * the buffer space was insufficient. */ int bvsnprintf(char *buf, int size, const char *fmt, va_list args) { int len; unsigned long num; int i, base; char *str, *start; const char *s; char ipbuf[STD_ADDRESS_P_LENGTH+1]; int flags; /* flags to number() */ int field_width; /* width of output field */ int precision; /* min. # of digits for integers; max number of chars for from string */ int qualifier; /* 'h', 'l', or 'L' for integer fields */ for (start=str=buf ; *fmt ; ++fmt, size-=(str-start), start=str) { if (*fmt != '%') { if (!size) return -1; *str++ = *fmt; continue; } /* process flags */ flags = 0; repeat: ++fmt; /* this also skips first '%' */ switch (*fmt) { case '-': flags |= LEFT; goto repeat; case '+': flags |= PLUS; goto repeat; case ' ': flags |= SPACE; goto repeat; case '#': flags |= SPECIAL; goto repeat; case '0': flags |= ZEROPAD; goto repeat; } /* get field width */ field_width = -1; if (is_digit(*fmt)) field_width = skip_atoi(&fmt); else if (*fmt == '*') { ++fmt; /* it's the next argument */ field_width = va_arg(args, int); if (field_width < 0) { field_width = -field_width; flags |= LEFT; } } /* get the precision */ precision = -1; if (*fmt == '.') { ++fmt; if (is_digit(*fmt)) precision = skip_atoi(&fmt); else if (*fmt == '*') { ++fmt; /* it's the next argument */ precision = va_arg(args, int); } if (precision < 0) precision = 0; } /* get the conversion qualifier */ qualifier = -1; if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L') { qualifier = *fmt; ++fmt; } /* default base */ base = 10; if (field_width > size) return -1; switch (*fmt) { case 'c': if (!(flags & LEFT)) while (--field_width > 0) *str++ = ' '; *str++ = (unsigned char) va_arg(args, int); while (--field_width > 0) *str++ = ' '; continue; case 'm': s = strerror(errno); goto str; case 'M': s = strerror(va_arg(args, int)); goto str; case 's': s = va_arg(args, char *); if (!s) s = "<NULL>"; str: len = strlen(s); if (precision >= 0 && len > precision) len = precision; if (len > size) return -1; if (!(flags & LEFT)) while (len < field_width--) *str++ = ' '; for (i = 0; i < len; ++i) *str++ = *s++; while (len < field_width--) *str++ = ' '; continue; case 'p': if (field_width == -1) { field_width = 2*sizeof(void *); flags |= ZEROPAD; } str = number(str, (unsigned long) va_arg(args, void *), 16, field_width, precision, flags, size); if (!str) return -1; continue; case 'n': if (qualifier == 'l') { long * ip = va_arg(args, long *); *ip = (str - buf); } else { int * ip = va_arg(args, int *); *ip = (str - buf); } continue; /* IP address */ case 'I': if (flags & SPECIAL) ip_ntox(va_arg(args, ip_addr), ipbuf); else { ip_ntop(va_arg(args, ip_addr), ipbuf); if (field_width > 0) field_width = STD_ADDRESS_P_LENGTH; } s = ipbuf; goto str; /* integer number formats - set up the flags and "break" */ case 'o': base = 8; break; case 'X': flags |= LARGE; case 'x': base = 16; break; case 'd': case 'i': flags |= SIGN; case 'u': break; default: if (size < 2) return -1; if (*fmt != '%') *str++ = '%'; if (*fmt) *str++ = *fmt; else --fmt; continue; } if (qualifier == 'l') num = va_arg(args, unsigned long); else if (qualifier == 'h') { num = (unsigned short) va_arg(args, int); if (flags & SIGN) num = (short) num; } else if (flags & SIGN) num = va_arg(args, int); else num = va_arg(args, unsigned int); str = number(str, num, base, field_width, precision, flags, size); if (!str) return -1; } if (!size) return -1; *str = '\0'; return str-buf; } /** * bvsprintf - BIRD's vsprintf() * @buf: buffer * @fmt: format string * @args: a list of arguments to be formatted * * This function is equivalent to bvsnprintf() with an infinite * buffer size. Please use carefully only when you are absolutely * sure the buffer won't overflow. */ int bvsprintf(char *buf, const char *fmt, va_list args) { return bvsnprintf(buf, 1000000000, fmt, args); } /** * bsprintf - BIRD's sprintf() * @buf: buffer * @fmt: format string * * This function is equivalent to bvsnprintf() with an infinite * buffer size and variable arguments instead of a &va_list. * Please use carefully only when you are absolutely * sure the buffer won't overflow. */ int bsprintf(char * buf, const char *fmt, ...) { va_list args; int i; va_start(args, fmt); i=bvsnprintf(buf, 1000000000, fmt, args); va_end(args); return i; } /** * bsnprintf - BIRD's snprintf() * @buf: buffer * @size: buffer size * @fmt: format string * * This function is equivalent to bsnprintf() with variable arguments instead of a &va_list. */ int bsnprintf(char * buf, int size, const char *fmt, ...) { va_list args; int i; va_start(args, fmt); i=bvsnprintf(buf, size, fmt, args); va_end(args); return i; }