diff --git a/sys/kern/subr_sbuf.c b/sys/kern/subr_sbuf.c index cdeaf690208f..b7f135e81206 100644 --- a/sys/kern/subr_sbuf.c +++ b/sys/kern/subr_sbuf.c @@ -1,954 +1,958 @@ /*- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD * * Copyright (c) 2000-2008 Poul-Henning Kamp * Copyright (c) 2000-2008 Dag-Erling Coïdan Smørgrav * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer * in this position and unchanged. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include __FBSDID("$FreeBSD$"); #include #ifdef _KERNEL #include #include #include #include #include #include #include #include #else /* _KERNEL */ #include #include #include #include #include #include #include #endif /* _KERNEL */ #include #ifdef _KERNEL static MALLOC_DEFINE(M_SBUF, "sbuf", "string buffers"); #define SBMALLOC(size, flags) malloc(size, M_SBUF, (flags) | M_ZERO) #define SBFREE(buf) free(buf, M_SBUF) #else /* _KERNEL */ #define KASSERT(e, m) #define SBMALLOC(size, flags) calloc(1, size) #define SBFREE(buf) free(buf) #endif /* _KERNEL */ /* * Predicates */ #define SBUF_ISDYNAMIC(s) ((s)->s_flags & SBUF_DYNAMIC) #define SBUF_ISDYNSTRUCT(s) ((s)->s_flags & SBUF_DYNSTRUCT) #define SBUF_ISFINISHED(s) ((s)->s_flags & SBUF_FINISHED) #define SBUF_ISDRAINATEOL(s) ((s)->s_flags & SBUF_DRAINATEOL) #define SBUF_HASROOM(s) ((s)->s_len < (s)->s_size - 1) #define SBUF_FREESPACE(s) ((s)->s_size - ((s)->s_len + 1)) #define SBUF_CANEXTEND(s) ((s)->s_flags & SBUF_AUTOEXTEND) #define SBUF_ISSECTION(s) ((s)->s_flags & SBUF_INSECTION) #define SBUF_NULINCLUDED(s) ((s)->s_flags & SBUF_INCLUDENUL) #define SBUF_ISDRAINTOEOR(s) ((s)->s_flags & SBUF_DRAINTOEOR) #define SBUF_DODRAINTOEOR(s) (SBUF_ISSECTION(s) && SBUF_ISDRAINTOEOR(s)) #define SBUF_MALLOCFLAG(s) \ (((s)->s_flags & SBUF_NOWAIT) ? M_NOWAIT : M_WAITOK) /* * Set / clear flags */ #define SBUF_SETFLAG(s, f) do { (s)->s_flags |= (f); } while (0) #define SBUF_CLEARFLAG(s, f) do { (s)->s_flags &= ~(f); } while (0) #define SBUF_MINSIZE 2 /* Min is 1 byte + nulterm. */ #define SBUF_MINEXTENDSIZE 16 /* Should be power of 2. */ #ifdef PAGE_SIZE #define SBUF_MAXEXTENDSIZE PAGE_SIZE #define SBUF_MAXEXTENDINCR PAGE_SIZE #else #define SBUF_MAXEXTENDSIZE 4096 #define SBUF_MAXEXTENDINCR 4096 #endif /* * Debugging support */ #if defined(_KERNEL) && defined(INVARIANTS) static void _assert_sbuf_integrity(const char *fun, struct sbuf *s) { KASSERT(s != NULL, ("%s called with a NULL sbuf pointer", fun)); KASSERT(s->s_buf != NULL, ("%s called with uninitialized or corrupt sbuf", fun)); if (SBUF_ISFINISHED(s) && SBUF_NULINCLUDED(s)) { KASSERT(s->s_len <= s->s_size, ("wrote past end of sbuf (%jd >= %jd)", (intmax_t)s->s_len, (intmax_t)s->s_size)); } else { KASSERT(s->s_len < s->s_size, ("wrote past end of sbuf (%jd >= %jd)", (intmax_t)s->s_len, (intmax_t)s->s_size)); } } static void _assert_sbuf_state(const char *fun, struct sbuf *s, int state) { KASSERT((s->s_flags & SBUF_FINISHED) == state, ("%s called with %sfinished or corrupt sbuf", fun, (state ? "un" : ""))); } #define assert_sbuf_integrity(s) _assert_sbuf_integrity(__func__, (s)) #define assert_sbuf_state(s, i) _assert_sbuf_state(__func__, (s), (i)) #else /* _KERNEL && INVARIANTS */ #define assert_sbuf_integrity(s) do { } while (0) #define assert_sbuf_state(s, i) do { } while (0) #endif /* _KERNEL && INVARIANTS */ #ifdef CTASSERT CTASSERT(powerof2(SBUF_MAXEXTENDSIZE)); CTASSERT(powerof2(SBUF_MAXEXTENDINCR)); #endif static int sbuf_extendsize(int size) { int newsize; if (size < (int)SBUF_MAXEXTENDSIZE) { newsize = SBUF_MINEXTENDSIZE; while (newsize < size) newsize *= 2; } else { newsize = roundup2(size, SBUF_MAXEXTENDINCR); } KASSERT(newsize >= size, ("%s: %d < %d\n", __func__, newsize, size)); return (newsize); } /* * 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, SBUF_MALLOCFLAG(s)); 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); } /* * Initialize an sbuf. * If buf is non-NULL, it points to a static or already-allocated string * big enough to hold at least length characters. */ struct sbuf * sbuf_new(struct sbuf *s, char *buf, int length, int flags) { KASSERT(length >= 0, ("attempt to create an sbuf of negative length (%d)", length)); KASSERT((flags & ~SBUF_USRFLAGMSK) == 0, ("%s called with invalid flags", __func__)); KASSERT((flags & SBUF_AUTOEXTEND) || length >= SBUF_MINSIZE, ("sbuf buffer %d smaller than minimum %d bytes", length, SBUF_MINSIZE)); flags &= SBUF_USRFLAGMSK; /* * Allocate 'DYNSTRUCT' sbuf from the heap, if NULL 's' was provided. */ if (s == NULL) { s = SBMALLOC(sizeof(*s), (flags & SBUF_NOWAIT) ? M_NOWAIT : M_WAITOK); if (s == NULL) goto out; SBUF_SETFLAG(s, SBUF_DYNSTRUCT); } else { /* * DYNSTRUCT SBMALLOC sbufs are allocated with M_ZERO, but * user-provided sbuf objects must be initialized. */ memset(s, 0, sizeof(*s)); } s->s_flags |= flags; s->s_size = length; s->s_buf = buf; /* * Never-written sbufs do not need \n termination. */ SBUF_SETFLAG(s, SBUF_DRAINATEOL); /* * Allocate DYNAMIC, i.e., heap data buffer backing the sbuf, if no * buffer was provided. */ if (s->s_buf == NULL) { if (SBUF_CANEXTEND(s)) s->s_size = sbuf_extendsize(s->s_size); s->s_buf = SBMALLOC(s->s_size, SBUF_MALLOCFLAG(s)); if (s->s_buf == NULL) goto out; SBUF_SETFLAG(s, SBUF_DYNAMIC); } out: if (s != NULL && s->s_buf == NULL) { if (SBUF_ISDYNSTRUCT(s)) SBFREE(s); s = NULL; } return (s); } #ifdef _KERNEL /* * Create an sbuf with uio data */ struct sbuf * sbuf_uionew(struct sbuf *s, struct uio *uio, int *error) { KASSERT(uio != NULL, ("%s called with NULL uio pointer", __func__)); KASSERT(error != NULL, ("%s called with NULL error pointer", __func__)); + if (uio->uio_resid >= INT_MAX || uio->uio_resid < SBUF_MINSIZE - 1) { + *error = EINVAL; + return (NULL); + } s = sbuf_new(s, NULL, uio->uio_resid + 1, 0); if (s == NULL) { *error = ENOMEM; return (NULL); } *error = uiomove(s->s_buf, uio->uio_resid, uio); if (*error != 0) { sbuf_delete(s); return (NULL); } s->s_len = s->s_size - 1; if (SBUF_ISSECTION(s)) s->s_sect_len = s->s_size - 1; *error = 0; return (s); } #endif int sbuf_get_flags(struct sbuf *s) { return (s->s_flags & SBUF_USRFLAGMSK); } void sbuf_clear_flags(struct sbuf *s, int flags) { s->s_flags &= ~(flags & SBUF_USRFLAGMSK); } void sbuf_set_flags(struct sbuf *s, int flags) { s->s_flags |= (flags & SBUF_USRFLAGMSK); } /* * Clear an sbuf and reset its position. */ void sbuf_clear(struct sbuf *s) { assert_sbuf_integrity(s); /* don't care if it's finished or not */ KASSERT(s->s_drain_func == NULL, ("%s makes no sense on sbuf %p with drain", __func__, s)); SBUF_CLEARFLAG(s, SBUF_FINISHED); s->s_error = 0; s->s_len = 0; s->s_rec_off = 0; s->s_sect_len = 0; } /* * Set the sbuf's end position to an arbitrary value. * Effectively truncates the sbuf at the new position. */ int sbuf_setpos(struct sbuf *s, ssize_t pos) { assert_sbuf_integrity(s); assert_sbuf_state(s, 0); KASSERT(pos >= 0, ("attempt to seek to a negative position (%jd)", (intmax_t)pos)); KASSERT(pos < s->s_size, ("attempt to seek past end of sbuf (%jd >= %jd)", (intmax_t)pos, (intmax_t)s->s_size)); KASSERT(!SBUF_ISSECTION(s), ("attempt to seek when in a section")); if (pos < 0 || pos > s->s_len) return (-1); s->s_len = pos; return (0); } /* * Drain into a counter. Counts amount of data without producing output. * Useful for cases like sysctl, where user may first request only size. * This allows to avoid pointless allocation/freeing of large buffers. */ int sbuf_count_drain(void *arg, const char *data __unused, int len) { size_t *sizep; sizep = (size_t *)arg; *sizep += len; return (len); } /* * Set up a drain function and argument on an sbuf to flush data to * when the sbuf buffer overflows. */ void sbuf_set_drain(struct sbuf *s, sbuf_drain_func *func, void *ctx) { assert_sbuf_state(s, 0); assert_sbuf_integrity(s); KASSERT(func == s->s_drain_func || s->s_len == 0, ("Cannot change drain to %p on non-empty sbuf %p", func, s)); s->s_drain_func = func; s->s_drain_arg = ctx; } /* * Call the drain and process the return. */ int sbuf_drain(struct sbuf *s) { int len; /* * Immediately return when no work to do, * or an error has already been accumulated. */ if ((s->s_len == 0) || (s->s_error != 0)) return(s->s_error); if (SBUF_DODRAINTOEOR(s) && s->s_rec_off == 0) return (s->s_error = EDEADLK); len = s->s_drain_func(s->s_drain_arg, s->s_buf, SBUF_DODRAINTOEOR(s) ? s->s_rec_off : s->s_len); if (len <= 0) { s->s_error = len ? -len : EDEADLK; return (s->s_error); } KASSERT(len > 0 && len <= s->s_len, ("Bad drain amount %d for sbuf %p", len, s)); s->s_len -= len; s->s_rec_off -= len; /* * Fast path for the expected case where all the data was * drained. */ if (s->s_len == 0) { /* * When the s_buf is entirely drained, we need to remember if * the last character was a '\n' or not for * sbuf_nl_terminate(). */ if (s->s_buf[len - 1] == '\n') SBUF_SETFLAG(s, SBUF_DRAINATEOL); else SBUF_CLEARFLAG(s, SBUF_DRAINATEOL); return (0); } /* * Move the remaining characters to the beginning of the * string. */ memmove(s->s_buf, s->s_buf + len, s->s_len); return (0); } /* * Append bytes to an sbuf. This is the core function for appending * to an sbuf and is the main place that deals with extending the * buffer and marking overflow. */ static void sbuf_put_bytes(struct sbuf *s, const char *buf, size_t len) { size_t n; assert_sbuf_integrity(s); assert_sbuf_state(s, 0); if (s->s_error != 0) return; while (len > 0) { if (SBUF_FREESPACE(s) <= 0) { /* * If there is a drain, use it, otherwise extend the * buffer. */ if (s->s_drain_func != NULL) (void)sbuf_drain(s); else if (sbuf_extend(s, len > INT_MAX ? INT_MAX : len) < 0) s->s_error = ENOMEM; if (s->s_error != 0) return; } n = SBUF_FREESPACE(s); if (len < n) n = len; memcpy(&s->s_buf[s->s_len], buf, n); s->s_len += n; if (SBUF_ISSECTION(s)) s->s_sect_len += n; len -= n; buf += n; } } static void sbuf_put_byte(struct sbuf *s, char c) { sbuf_put_bytes(s, &c, 1); } /* * Append a byte string to an sbuf. */ int sbuf_bcat(struct sbuf *s, const void *buf, size_t len) { sbuf_put_bytes(s, buf, len); if (s->s_error != 0) return (-1); return (0); } #ifdef _KERNEL /* * Copy a byte string from userland into an sbuf. */ int sbuf_bcopyin(struct sbuf *s, const void *uaddr, size_t len) { assert_sbuf_integrity(s); assert_sbuf_state(s, 0); KASSERT(s->s_drain_func == NULL, ("Nonsensical copyin to sbuf %p with a drain", s)); if (s->s_error != 0) return (-1); if (len == 0) return (0); if (len > SBUF_FREESPACE(s)) { sbuf_extend(s, len - SBUF_FREESPACE(s)); if (SBUF_FREESPACE(s) < len) len = SBUF_FREESPACE(s); } if (copyin(uaddr, s->s_buf + s->s_len, len) != 0) return (-1); s->s_len += len; return (0); } #endif /* * Copy a byte string into an sbuf. */ int sbuf_bcpy(struct sbuf *s, const void *buf, size_t len) { assert_sbuf_integrity(s); assert_sbuf_state(s, 0); sbuf_clear(s); return (sbuf_bcat(s, buf, len)); } /* * Append a string to an sbuf. */ int sbuf_cat(struct sbuf *s, const char *str) { size_t n; n = strlen(str); sbuf_put_bytes(s, str, n); if (s->s_error != 0) return (-1); return (0); } #ifdef _KERNEL /* * Append a string from userland to an sbuf. */ int sbuf_copyin(struct sbuf *s, const void *uaddr, size_t len) { size_t done; assert_sbuf_integrity(s); assert_sbuf_state(s, 0); KASSERT(s->s_drain_func == NULL, ("Nonsensical copyin to sbuf %p with a drain", s)); if (s->s_error != 0) return (-1); if (len == 0) len = SBUF_FREESPACE(s); /* XXX return 0? */ if (len > SBUF_FREESPACE(s)) { sbuf_extend(s, len); if (SBUF_FREESPACE(s) < len) len = SBUF_FREESPACE(s); } switch (copyinstr(uaddr, s->s_buf + s->s_len, len + 1, &done)) { case ENAMETOOLONG: s->s_error = ENOMEM; /* fall through */ case 0: s->s_len += done - 1; if (SBUF_ISSECTION(s)) s->s_sect_len += done - 1; break; default: return (-1); /* XXX */ } return (done); } #endif /* * Copy a string into an sbuf. */ int sbuf_cpy(struct sbuf *s, const char *str) { assert_sbuf_integrity(s); assert_sbuf_state(s, 0); sbuf_clear(s); return (sbuf_cat(s, str)); } /* * Format the given argument list and append the resulting string to an sbuf. */ #ifdef _KERNEL /* * Append a non-NUL character to an sbuf. This prototype signature is * suitable for use with kvprintf(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)kvprintf(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); if (len < 0) { s->s_error = errno; return (-1); } 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); /* sbuf_drain() sets s_error. */ else if (sbuf_extend(s, len - SBUF_FREESPACE(s)) != 0) s->s_error = error = ENOMEM; } 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; 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); } #endif /* _KERNEL */ /* * Format the given arguments and append the resulting string to an sbuf. */ int sbuf_printf(struct sbuf *s, const char *fmt, ...) { va_list ap; int result; va_start(ap, fmt); result = sbuf_vprintf(s, fmt, ap); va_end(ap); return (result); } /* * Append a character to an sbuf. */ int sbuf_putc(struct sbuf *s, int c) { sbuf_put_byte(s, c); if (s->s_error != 0) return (-1); return (0); } /* * Append a trailing newline to a non-empty sbuf, if one is not already * present. Handles sbufs with drain functions correctly. */ int sbuf_nl_terminate(struct sbuf *s) { assert_sbuf_integrity(s); assert_sbuf_state(s, 0); /* * If the s_buf isn't empty, the last byte is simply s_buf[s_len - 1]. * * If the s_buf is empty because a drain function drained it, we * remember if the last byte was a \n with the SBUF_DRAINATEOL flag in * sbuf_drain(). * * In either case, we only append a \n if the previous character was * something else. */ if (s->s_len == 0) { if (!SBUF_ISDRAINATEOL(s)) sbuf_put_byte(s, '\n'); } else if (s->s_buf[s->s_len - 1] != '\n') sbuf_put_byte(s, '\n'); if (s->s_error != 0) return (-1); return (0); } /* * Trim whitespace characters from end of an sbuf. */ int sbuf_trim(struct sbuf *s) { assert_sbuf_integrity(s); assert_sbuf_state(s, 0); KASSERT(s->s_drain_func == NULL, ("%s makes no sense on sbuf %p with drain", __func__, s)); if (s->s_error != 0) return (-1); while (s->s_len > 0 && isspace(s->s_buf[s->s_len-1])) { --s->s_len; if (SBUF_ISSECTION(s)) s->s_sect_len--; } return (0); } /* * Check if an sbuf has an error. */ int sbuf_error(const struct sbuf *s) { return (s->s_error); } /* * Finish off an sbuf. */ int sbuf_finish(struct sbuf *s) { assert_sbuf_integrity(s); assert_sbuf_state(s, 0); s->s_buf[s->s_len] = '\0'; if (SBUF_NULINCLUDED(s)) s->s_len++; if (s->s_drain_func != NULL) { while (s->s_len > 0 && s->s_error == 0) s->s_error = sbuf_drain(s); } SBUF_SETFLAG(s, SBUF_FINISHED); #ifdef _KERNEL return (s->s_error); #else if (s->s_error != 0) { errno = s->s_error; return (-1); } return (0); #endif } /* * Return a pointer to the sbuf data. */ char * sbuf_data(struct sbuf *s) { assert_sbuf_integrity(s); assert_sbuf_state(s, SBUF_FINISHED); KASSERT(s->s_drain_func == NULL, ("%s makes no sense on sbuf %p with drain", __func__, s)); return (s->s_buf); } /* * Return the length of the sbuf data. */ ssize_t sbuf_len(struct sbuf *s) { assert_sbuf_integrity(s); /* don't care if it's finished or not */ KASSERT(s->s_drain_func == NULL, ("%s makes no sense on sbuf %p with drain", __func__, s)); if (s->s_error != 0) return (-1); /* If finished, nulterm is already in len, else add one. */ if (SBUF_NULINCLUDED(s) && !SBUF_ISFINISHED(s)) return (s->s_len + 1); return (s->s_len); } /* * Clear an sbuf, free its buffer if necessary. */ void sbuf_delete(struct sbuf *s) { int isdyn; assert_sbuf_integrity(s); /* don't care if it's finished or not */ if (SBUF_ISDYNAMIC(s)) SBFREE(s->s_buf); isdyn = SBUF_ISDYNSTRUCT(s); memset(s, 0, sizeof(*s)); if (isdyn) SBFREE(s); } /* * Check if an sbuf has been finished. */ int sbuf_done(const struct sbuf *s) { return (SBUF_ISFINISHED(s)); } /* * Start a section. */ void sbuf_start_section(struct sbuf *s, ssize_t *old_lenp) { assert_sbuf_integrity(s); assert_sbuf_state(s, 0); if (!SBUF_ISSECTION(s)) { KASSERT(s->s_sect_len == 0, ("s_sect_len != 0 when starting a section")); if (old_lenp != NULL) *old_lenp = -1; s->s_rec_off = s->s_len; SBUF_SETFLAG(s, SBUF_INSECTION); } else { KASSERT(old_lenp != NULL, ("s_sect_len should be saved when starting a subsection")); *old_lenp = s->s_sect_len; s->s_sect_len = 0; } } /* * End the section padding to the specified length with the specified * character. */ ssize_t sbuf_end_section(struct sbuf *s, ssize_t old_len, size_t pad, int c) { ssize_t len; assert_sbuf_integrity(s); assert_sbuf_state(s, 0); KASSERT(SBUF_ISSECTION(s), ("attempt to end a section when not in a section")); if (pad > 1) { len = roundup(s->s_sect_len, pad) - s->s_sect_len; for (; s->s_error == 0 && len > 0; len--) sbuf_put_byte(s, c); } len = s->s_sect_len; if (old_len == -1) { s->s_rec_off = s->s_sect_len = 0; SBUF_CLEARFLAG(s, SBUF_INSECTION); } else { s->s_sect_len += old_len; } if (s->s_error != 0) return (-1); return (len); }