/* * Format the given argument list and append the resulting string to an sbuf. */ int sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap) { va_list ap_copy; int len; assert_sbuf_integrity(s); assert_sbuf_state(s, 0); KASSERT(fmt != NULL, ("%s called with a NULL format string", __func__)); if (SBUF_HASOVERFLOWED(s)) return (-1); do { va_copy(ap_copy, ap); len = vsnprintf(&s->s_buf[s->s_len], SBUF_FREESPACE(s) + 1, fmt, ap_copy); va_end(ap_copy); } while (len > SBUF_FREESPACE(s) && sbuf_extend(s, len - SBUF_FREESPACE(s)) == 0); /* * s->s_len is the length of the string, without the terminating nul. * When updating s->s_len, we must subtract 1 from the length that * we passed into vsnprintf() because that length includes the * terminating nul. * * vsnprintf() returns the amount that would have been copied, * given sufficient space, hence the min() calculation below. */ s->s_len += min(len, SBUF_FREESPACE(s)); if (!SBUF_HASROOM(s) && !SBUF_CANEXTEND(s)) SBUF_SETFLAG(s, SBUF_OVERFLOWED); KASSERT(s->s_len < s->s_size, ("wrote past end of sbuf (%d >= %d)", s->s_len, s->s_size)); if (SBUF_HASOVERFLOWED(s)) return (-1); return (0); }
/* * Extend an sbuf. */ static int sbuf_extend(struct sbuf *s, int addlen) { char *newbuf; int newsize; if (!SBUF_CANEXTEND(s)) return (-1); newsize = sbuf_extendsize(s->s_size + addlen); newbuf = SBMALLOC(newsize); if (newbuf == NULL) return (-1); memcpy(newbuf, s->s_buf, s->s_size); if (SBUF_ISDYNAMIC(s)) SBFREE(s->s_buf); else SBUF_SETFLAG(s, SBUF_DYNAMIC); s->s_buf = newbuf; s->s_size = newsize; return (0); }
/* * Append a non-NUL character to an sbuf. This prototype signature is * suitable for use with kvcprintf(9). */ static void sbuf_putc_func(int c, void *arg) { if (c != '\0') sbuf_put_byte(arg, c); } int sbuf_vprintf(struct sbuf *s, const char *fmt, __va_list ap) { assert_sbuf_integrity(s); assert_sbuf_state(s, 0); KASSERT(fmt != NULL, ("%s called with a NULL format string", __func__)); (void)kvcprintf(fmt, sbuf_putc_func, s, 10, ap); if (s->s_error != 0) return (-1); return (0); } #else /* !_KERNEL */ int sbuf_vprintf(struct sbuf *s, const char *fmt, __va_list ap) { __va_list ap_copy; int error, len; assert_sbuf_integrity(s); assert_sbuf_state(s, 0); KASSERT(fmt != NULL, ("%s called with a NULL format string", __func__)); if (s->s_error != 0) return (-1); /* * For the moment, there is no way to get vsnprintf(3) to hand * back a character at a time, to push everything into * sbuf_putc_func() as was done for the kernel. * * In userspace, while drains are useful, there's generally * not a problem attempting to malloc(3) on out of space. So * expand a userland sbuf if there is not enough room for the * data produced by sbuf_[v]printf(3). */ error = 0; do { va_copy(ap_copy, ap); len = vsnprintf(&s->s_buf[s->s_len], SBUF_FREESPACE(s) + 1, fmt, ap_copy); __va_end(ap_copy); if (SBUF_FREESPACE(s) >= len) break; /* Cannot print with the current available space. */ if (s->s_drain_func != NULL && s->s_len > 0) error = sbuf_drain(s); else error = sbuf_extend(s, len - SBUF_FREESPACE(s)); } while (error == 0); /* * s->s_len is the length of the string, without the terminating nul. * When updating s->s_len, we must subtract 1 from the length that * we passed into vsnprintf() because that length includes the * terminating nul. * * vsnprintf() returns the amount that would have been copied, * given sufficient space, so don't over-increment s_len. */ if (SBUF_FREESPACE(s) < len) len = SBUF_FREESPACE(s); s->s_len += len; if (SBUF_ISSECTION(s)) s->s_sect_len += len; if (!SBUF_HASROOM(s) && !SBUF_CANEXTEND(s)) s->s_error = ENOMEM; KASSERT(s->s_len < s->s_size, ("wrote past end of sbuf (%d >= %d)", s->s_len, s->s_size)); if (s->s_error != 0) return (-1); return (0); }