/*++ /* NAME /* vstream 3 /* SUMMARY /* light-weight buffered I/O package /* SYNOPSIS /* #include <vstream.h> /* /* VSTREAM *vstream_fopen(path, flags, mode) /* const char *path; /* int flags; /* mode_t mode; /* /* VSTREAM *vstream_fdopen(fd, flags) /* int fd; /* int flags; /* /* int vstream_fclose(stream) /* VSTREAM *stream; /* /* int vstream_fdclose(stream) /* VSTREAM *stream; /* /* VSTREAM *vstream_printf(format, ...) /* const char *format; /* /* VSTREAM *vstream_fprintf(stream, format, ...) /* VSTREAM *stream; /* const char *format; /* /* int VSTREAM_GETC(stream) /* VSTREAM *stream; /* /* int VSTREAM_PUTC(ch, stream) /* int ch; /* /* int VSTREAM_GETCHAR(void) /* /* int VSTREAM_PUTCHAR(ch) /* int ch; /* /* int vstream_ungetc(stream, ch) /* VSTREAM *stream; /* int ch; /* /* int vstream_fputs(str, stream) /* const char *str; /* VSTREAM *stream; /* /* off_t vstream_ftell(stream) /* VSTREAM *stream; /* /* off_t vstream_fseek(stream, offset, whence) /* VSTREAM *stream; /* off_t offset; /* int whence; /* /* int vstream_fflush(stream) /* VSTREAM *stream; /* /* int vstream_fpurge(stream, direction) /* VSTREAM *stream; /* int direction; /* /* ssize_t vstream_fread(stream, buf, len) /* VSTREAM *stream; /* char *buf; /* ssize_t len; /* /* ssize_t vstream_fwrite(stream, buf, len) /* VSTREAM *stream; /* const char *buf; /* ssize_t len; /* /* void vstream_control(stream, name, ...) /* VSTREAM *stream; /* int name; /* /* int vstream_fileno(stream) /* VSTREAM *stream; /* /* const ssize_t vstream_req_bufsize(stream) /* VSTREAM *stream; /* /* void *vstream_context(stream) /* VSTREAM *stream; /* /* int vstream_ferror(stream) /* VSTREAM *stream; /* /* int vstream_ftimeout(stream) /* VSTREAM *stream; /* /* int vstream_feof(stream) /* VSTREAM *stream; /* /* int vstream_clearerr(stream) /* VSTREAM *stream; /* /* const char *VSTREAM_PATH(stream) /* VSTREAM *stream; /* /* char *vstream_vprintf(format, ap) /* const char *format; /* va_list *ap; /* /* char *vstream_vfprintf(stream, format, ap) /* VSTREAM *stream; /* const char *format; /* va_list *ap; /* /* ssize_t vstream_bufstat(stream, command) /* VSTREAM *stream; /* int command; /* /* ssize_t vstream_peek(stream) /* VSTREAM *stream; /* /* const char *vstream_peek_data(stream) /* VSTREAM *stream; /* /* int vstream_setjmp(stream) /* VSTREAM *stream; /* /* void vstream_longjmp(stream, val) /* VSTREAM *stream; /* int val; /* /* time_t vstream_ftime(stream) /* VSTREAM *stream; /* /* struct timeval vstream_ftimeval(stream) /* VSTREAM *stream; /* /* int vstream_rd_error(stream) /* VSTREAM *stream; /* /* int vstream_wr_error(stream) /* VSTREAM *stream; /* /* int vstream_rd_timeout(stream) /* VSTREAM *stream; /* /* int vstream_wr_timeout(stream) /* VSTREAM *stream; /* /* int vstream_fstat(stream, flags) /* VSTREAM *stream; /* int flags; /* DESCRIPTION /* The \fIvstream\fR module implements light-weight buffered I/O /* similar to the standard I/O routines. /* /* The interface is implemented in terms of VSTREAM structure /* pointers, also called streams. For convenience, three streams /* are predefined: VSTREAM_IN, VSTREAM_OUT, and VSTREAM_ERR. These /* streams are connected to the standard input, output and error /* file descriptors, respectively. /* /* Although the interface is patterned after the standard I/O /* library, there are some major differences: /* .IP \(bu /* File descriptors are not limited to the range 0..255. This /* was reason #1 to write these routines in the first place. /* .IP \(bu /* The application can switch between reading and writing on /* the same stream without having to perform a flush or seek /* operation, and can change write position without having to /* flush. This was reason #2. Upon position or direction change, /* unread input is discarded, and unwritten output is flushed /* automatically. Exception: with double-buffered streams, unread /* input is not discarded upon change of I/O direction, and /* output flushing is delayed until the read buffer must be refilled. /* .IP \(bu /* A bidirectional stream can read and write with the same buffer /* and file descriptor, or it can have separate read/write /* buffers and/or file descriptors. /* .IP \(bu /* No automatic flushing of VSTREAM_OUT upon program exit, or of /* VSTREAM_ERR at any time. No unbuffered or line buffered modes. /* This functionality may be added when it is really needed. /* .PP /* vstream_fopen() opens the named file and associates a buffered /* stream with it. The \fIpath\fR, \fIflags\fR and \fImode\fR /* arguments are passed on to the open(2) routine. The result is /* a null pointer in case of problems. The \fIpath\fR argument is /* copied and can be looked up with VSTREAM_PATH(). /* /* vstream_fdopen() takes an open file and associates a buffered /* stream with it. The \fIflags\fR argument specifies how the file /* was opened. vstream_fdopen() either succeeds or never returns. /* /* vstream_fclose() closes the named buffered stream. The result /* is 0 in case of success, VSTREAM_EOF in case of problems. /* vstream_fclose() reports the same errors as vstream_ferror(). /* /* vstream_fdclose() leaves the file(s) open but is otherwise /* identical to vstream_fclose(). /* /* vstream_fprintf() formats its arguments according to the /* \fIformat\fR argument and writes the result to the named stream. /* The result is the stream argument. It understands the s, c, d, u, /* o, x, X, e, f and g format types, the l modifier, field width and /* precision, sign, and padding with zeros or spaces. In addition, /* vstream_fprintf() recognizes the %m format specifier and expands /* it to the error message corresponding to the current value of the /* global \fIerrno\fR variable. /* /* vstream_printf() performs formatted output to the standard output /* stream. /* /* VSTREAM_GETC() reads the next character from the named stream. /* The result is VSTREAM_EOF when end-of-file is reached or if a read /* error was detected. VSTREAM_GETC() is an unsafe macro that /* evaluates some arguments more than once. /* /* VSTREAM_GETCHAR() is an alias for VSTREAM_GETC(VSTREAM_IN). /* /* VSTREAM_PUTC() appends the specified character to the specified /* stream. The result is the stored character, or VSTREAM_EOF in /* case of problems. VSTREAM_PUTC() is an unsafe macro that /* evaluates some arguments more than once. /* /* VSTREAM_PUTCHAR(c) is an alias for VSTREAM_PUTC(c, VSTREAM_OUT). /* /* vstream_ungetc() pushes back a character onto the specified stream /* and returns the character, or VSTREAM_EOF in case of problems. /* It is an error to push back before reading (or immediately after /* changing the stream offset via vstream_fseek()). Upon successful /* return, vstream_ungetc() clears the end-of-file stream flag. /* /* vstream_fputs() appends the given null-terminated string to the /* specified buffered stream. The result is 0 in case of success, /* VSTREAM_EOF in case of problems. /* /* vstream_ftell() returns the file offset for the specified stream, /* -1 if the stream is connected to a non-seekable file. /* /* vstream_fseek() changes the file position for the next read or write /* operation. Unwritten output is flushed. With unidirectional streams, /* unread input is discarded. The \fIoffset\fR argument specifies the file /* position from the beginning of the file (\fIwhence\fR is SEEK_SET), /* from the current file position (\fIwhence\fR is SEEK_CUR), or from /* the file end (SEEK_END). The result value is the file offset /* from the beginning of the file, -1 in case of problems. /* /* vstream_fflush() flushes unwritten data to a file that was /* opened in read-write or write-only mode. /* vstream_fflush() returns 0 in case of success, VSTREAM_EOF in /* case of problems. It is an error to flush a read-only stream. /* vstream_fflush() reports the same errors as vstream_ferror(). /* /* vstream_fpurge() discards the contents of the stream buffer. /* If direction is VSTREAM_PURGE_READ, it discards unread data, /* else if direction is VSTREAM_PURGE_WRITE, it discards unwritten /* data. In the case of a double-buffered stream, if direction is /* VSTREAM_PURGE_BOTH, it discards the content of both the read /* and write buffers. vstream_fpurge() returns 0 in case of success, /* VSTREAM_EOF in case of problems. /* /* vstream_fread() and vstream_fwrite() perform unformatted I/O /* on the named stream. The result value is the number of bytes /* transferred. A short count is returned in case of end-of-file /* or error conditions. /* /* vstream_control() allows the user to fine tune the behavior of /* the specified stream. The arguments are a list of (name, /* value) pairs, terminated with VSTREAM_CTL_END. /* The following lists the names and the types of the corresponding /* value arguments. /* .IP "VSTREAM_CTL_READ_FN (ssize_t (*)(int, void *, size_t, int, void *))" /* The argument specifies an alternative for the timed_read(3) function, /* for example, a read function that performs decryption. /* This function receives as arguments a file descriptor, buffer pointer, /* buffer length, timeout value, and the VSTREAM's context value. /* A timeout value <= 0 disables the time limit. /* This function should return the positive number of bytes transferred, /* 0 upon EOF, and -1 upon error with errno set appropriately. /* .IP "VSTREAM_CTL_WRITE_FN (ssize_t (*)(int, void *, size_t, int, void *))" /* The argument specifies an alternative for the timed_write(3) function, /* for example, a write function that performs encryption. /* This function receives as arguments a file descriptor, buffer pointer, /* buffer length, timeout value, and the VSTREAM's context value. /* A timeout value <= 0 disables the time limit. /* This function should return the positive number of bytes transferred, /* and -1 upon error with errno set appropriately. Instead of -1 it may /* also return 0, e.g., upon remote party-initiated protocol shutdown. /* .IP "VSTREAM_CTL_CONTEXT (char *)" /* The argument specifies application context that is passed on to /* the application-specified read/write routines. No copy is made. /* .IP "VSTREAM_CTL_PATH (char *)" /* Updates the stored pathname of the specified stream. The pathname /* is copied. /* .IP "VSTREAM_CTL_DOUBLE (no value)" /* Use separate buffers for reading and for writing. This prevents /* unread input from being discarded upon change of I/O direction. /* .IP "VSTREAM_CTL_READ_FD (int) /* The argument specifies the file descriptor to be used for reading. /* This feature is limited to double-buffered streams, and makes the /* stream non-seekable. /* .IP "VSTREAM_CTL_WRITE_FD (int) /* The argument specifies the file descriptor to be used for writing. /* This feature is limited to double-buffered streams, and makes the /* stream non-seekable. /* .IP "VSTREAM_CTL_SWAP_FD (VSTREAM *)" /* The argument specifies a VSTREAM pointer; the request swaps the /* file descriptor members of the two streams. This feature is limited /* to streams that are both double-buffered or both single-buffered. /* .IP "VSTREAM_CTL_DUPFD (int)" /* The argument specifies a minimum file descriptor value. If /* the actual stream's file descriptors are below the minimum, /* reallocate the descriptors to the first free value greater /* than or equal to the minimum. The VSTREAM_CTL_DUPFD macro /* is defined only on systems with fcntl() F_DUPFD support. /* .IP "VSTREAM_CTL_WAITPID_FN (int (*)(pid_t, WAIT_STATUS_T *, int))" /* A pointer to function that behaves like waitpid(). This information /* is used by the vstream_pclose() routine. /* .IP "VSTREAM_CTL_TIMEOUT (int) /* The deadline for a descriptor to become readable in case of a read /* request, or writable in case of a write request. Specify a value /* of 0 to disable deadlines. /* .IP "VSTREAM_CTL_EXCEPT (no value)" /* Enable exception handling with vstream_setjmp() and vstream_longjmp(). /* This involves allocation of additional memory that normally isn't /* used. /* .IP "VSTREAM_CTL_BUFSIZE (ssize_t)" /* Specify a non-default write buffer size, or zero to implement /* a no-op. Requests to shrink an existing buffer size are /* ignored. Requests to change a fixed-size buffer (stdin, /* stdout, stderr) are not allowed. /* /* NOTE: the VSTREAM_CTL_BUFSIZE request specifies intent, not /* reality. Actual buffer sizes are not updated immediately. /* Instead, an existing write buffer will be resized when it /* is full, and an existing read buffer will be resized when /* the buffer is filled. /* /* NOTE: the VSTREAM_CTL_BUFSIZE argument type is ssize_t, not /* int. Use an explicit cast to avoid problems on LP64 /* environments and other environments where ssize_t is larger /* than int. /* .IP VSTREAM_CTL_START_DEADLINE /* Change the VSTREAM_CTL_TIMEOUT behavior, to limit the total /* time for all subsequent file descriptor read or write /* operations, and recharge the deadline timer. /* .IP VSTREAM_CTL_STOP_DEADLINE /* Revert VSTREAM_CTL_TIMEOUT behavior to the default, i.e. /* a time limit for individual file descriptor read or write /* operations. /* .PP /* vstream_fileno() gives access to the file handle associated with /* a buffered stream. With streams that have separate read/write /* file descriptors, the result is the current descriptor. /* /* vstream_req_bufsize() returns the requested buffer size for /* the named stream (default: VSTREAM_BUFSIZE). The result /* value reflects intent, not reality: actual buffer sizes are /* not updated immediately when the requested buffer size is /* specified with vstream_control(). Instead, an existing /* write buffer will be resized when it is full, and an existing /* read buffer will be resized when the buffer is filled. /* /* vstream_context() returns the application context that is passed on to /* the application-specified read/write routines. /* /* VSTREAM_PATH() is an unsafe macro that returns the name stored /* with vstream_fopen() or with vstream_control(). The macro is /* unsafe because it evaluates some arguments more than once. /* /* vstream_feof() returns non-zero when a previous operation on the /* specified stream caused an end-of-file condition. /* Although further read requests after EOF may complete /* succesfully, vstream_feof() will keep returning non-zero /* until vstream_clearerr() is called for that stream. /* /* vstream_ferror() returns non-zero when a previous operation on the /* specified stream caused a non-EOF error condition, including timeout. /* After a non-EOF error on a stream, no I/O request will /* complete until after vstream_clearerr() is called for that stream. /* /* vstream_ftimeout() returns non-zero when a previous operation on the /* specified stream caused a timeout error condition. See /* vstream_ferror() for error persistence details. /* /* vstream_clearerr() resets the timeout, error and end-of-file indication /* of the specified stream, and returns no useful result. /* /* vstream_vfprintf() provides an alternate interface /* for formatting an argument list according to a format string. /* /* vstream_vprintf() provides a similar alternative interface. /* /* vstream_bufstat() provides input and output buffer status /* information. The command is one of the following: /* .IP VSTREAM_BST_IN_PEND /* Return the number of characters that can be read without /* refilling the read buffer. /* .IP VSTREAM_BST_OUT_PEND /* Return the number of characters that are waiting in the /* write buffer. /* .PP /* vstream_peek() returns the number of characters that can be /* read from the named stream without refilling the read buffer. /* This is an alias for vstream_bufstat(stream, VSTREAM_BST_IN_PEND). /* /* vstream_peek_data() returns a pointer to the unread bytes /* that exist according to vstream_peek(). /* /* vstream_setjmp() saves processing context and makes that context /* available for use with vstream_longjmp(). Normally, vstream_setjmp() /* returns zero. A non-zero result means that vstream_setjmp() returned /* through a vstream_longjmp() call; the result is the \fIval\fR argment /* given to vstream_longjmp(). /* /* NB: non-local jumps such as vstream_longjmp() are not safe /* for jumping out of any routine that manipulates VSTREAM data. /* longjmp() like calls are best avoided in signal handlers. /* /* vstream_ftime() returns the time of initialization, the last buffer /* fill operation, or the last buffer flush operation for the specified /* stream. This information is maintained only when stream timeouts are /* enabled. /* /* vstream_ftimeval() is like vstream_ftime() but returns more /* detail. /* /* vstream_rd_mumble() and vstream_wr_mumble() report on /* read and write error conditions, respectively. /* /* vstream_fstat() queries stream status information about /* user-requested features. The \fIflags\fR argument is the /* bitwise OR of one or more of the following, and the result /* value is the bitwise OR of the features that are activated. /* .IP VSTREAM_FLAG_DEADLINE /* The deadline feature is activated. /* .IP VSTREAM_FLAG_DOUBLE /* The double-buffering feature is activated. /* DIAGNOSTICS /* Panics: interface violations. Fatal errors: out of memory. /* SEE ALSO /* timed_read(3) default read routine /* timed_write(3) default write routine /* vbuf_print(3) formatting engine /* setjmp(3) non-local jumps /* BUGS /* Should use mmap() on reasonable systems. /* LICENSE /* .ad /* .fi /* The Secure Mailer license must be distributed with this software. /* AUTHOR(S) /* Wietse Venema /* IBM T.J. Watson Research /* P.O. Box 704 /* Yorktown Heights, NY 10598, USA /*--*/ /* System library. */ #include <sys_defs.h> #include <stdlib.h> /* 44BSD stdarg.h uses abort() */ #include <stdarg.h> #include <stddef.h> #include <unistd.h> #include <fcntl.h> #include <time.h> #include <errno.h> #include <string.h> /* Utility library. */ #include "mymalloc.h" #include "msg.h" #include "vbuf_print.h" #include "iostuff.h" #include "vstring.h" #include "vstream.h" /* Application-specific. */ /* * Forward declarations. */ static int vstream_buf_get_ready(VBUF *); static int vstream_buf_put_ready(VBUF *); static int vstream_buf_space(VBUF *, ssize_t); /* * Initialization of the three pre-defined streams. Pre-allocate a static * I/O buffer for the standard error stream, so that the error handler can * produce a diagnostic even when memory allocation fails. */ static unsigned char vstream_fstd_buf[VSTREAM_BUFSIZE]; VSTREAM vstream_fstd[] = { {{ 0, /* flags */ 0, 0, 0, 0, /* buffer */ vstream_buf_get_ready, vstream_buf_put_ready, vstream_buf_space, }, STDIN_FILENO, (VSTREAM_FN) timed_read, (VSTREAM_FN) timed_write, VSTREAM_BUFSIZE,}, {{ 0, /* flags */ 0, 0, 0, 0, /* buffer */ vstream_buf_get_ready, vstream_buf_put_ready, vstream_buf_space, }, STDOUT_FILENO, (VSTREAM_FN) timed_read, (VSTREAM_FN) timed_write, VSTREAM_BUFSIZE,}, {{ VBUF_FLAG_FIXED | VSTREAM_FLAG_WRITE, vstream_fstd_buf, VSTREAM_BUFSIZE, VSTREAM_BUFSIZE, vstream_fstd_buf, vstream_buf_get_ready, vstream_buf_put_ready, vstream_buf_space, }, STDERR_FILENO, (VSTREAM_FN) timed_read, (VSTREAM_FN) timed_write, VSTREAM_BUFSIZE,}, }; #define VSTREAM_STATIC(v) ((v) >= VSTREAM_IN && (v) <= VSTREAM_ERR) /* * A bunch of macros to make some expressions more readable. XXX We're * assuming that O_RDONLY == 0, O_WRONLY == 1, O_RDWR == 2. */ #define VSTREAM_ACC_MASK(f) ((f) & (O_APPEND | O_WRONLY | O_RDWR)) #define VSTREAM_CAN_READ(f) (VSTREAM_ACC_MASK(f) == O_RDONLY \ || VSTREAM_ACC_MASK(f) == O_RDWR) #define VSTREAM_CAN_WRITE(f) (VSTREAM_ACC_MASK(f) & O_WRONLY \ || VSTREAM_ACC_MASK(f) & O_RDWR \ || VSTREAM_ACC_MASK(f) & O_APPEND) #define VSTREAM_BUF_COUNT(bp, n) \ ((bp)->flags & VSTREAM_FLAG_READ ? -(n) : (n)) #define VSTREAM_BUF_AT_START(bp) { \ (bp)->cnt = VSTREAM_BUF_COUNT((bp), (bp)->len); \ (bp)->ptr = (bp)->data; \ } #define VSTREAM_BUF_AT_OFFSET(bp, offset) { \ (bp)->ptr = (bp)->data + (offset); \ (bp)->cnt = VSTREAM_BUF_COUNT(bp, (bp)->len - (offset)); \ } #define VSTREAM_BUF_AT_END(bp) { \ (bp)->cnt = 0; \ (bp)->ptr = (bp)->data + (bp)->len; \ } #define VSTREAM_BUF_ZERO(bp) { \ (bp)->flags = 0; \ (bp)->data = (bp)->ptr = 0; \ (bp)->len = (bp)->cnt = 0; \ } #define VSTREAM_BUF_ACTIONS(bp, get_action, put_action, space_action) { \ (bp)->get_ready = (get_action); \ (bp)->put_ready = (put_action); \ (bp)->space = (space_action); \ } #define VSTREAM_SAVE_STATE(stream, buffer, filedes) { \ stream->buffer = stream->buf; \ stream->filedes = stream->fd; \ } #define VSTREAM_RESTORE_STATE(stream, buffer, filedes) do { \ stream->buffer.flags = stream->buf.flags; \ stream->buf = stream->buffer; \ stream->fd = stream->filedes; \ } while(0) #define VSTREAM_FORK_STATE(stream, buffer, filedes) { \ stream->buffer = stream->buf; \ stream->filedes = stream->fd; \ stream->buffer.data = stream->buffer.ptr = 0; \ stream->buffer.len = stream->buffer.cnt = 0; \ stream->buffer.flags &= ~VSTREAM_FLAG_FIXED; \ }; #define VSTREAM_FLAG_READ_DOUBLE (VSTREAM_FLAG_READ | VSTREAM_FLAG_DOUBLE) #define VSTREAM_FLAG_WRITE_DOUBLE (VSTREAM_FLAG_WRITE | VSTREAM_FLAG_DOUBLE) #define VSTREAM_FFLUSH_SOME(stream) \ vstream_fflush_some((stream), (stream)->buf.len - (stream)->buf.cnt) /* Note: this does not change a negative result into a zero result. */ #define VSTREAM_SUB_TIME(x, y, z) \ do { \ (x).tv_sec = (y).tv_sec - (z).tv_sec; \ (x).tv_usec = (y).tv_usec - (z).tv_usec; \ while ((x).tv_usec < 0) { \ (x).tv_usec += 1000000; \ (x).tv_sec -= 1; \ } \ while ((x).tv_usec >= 1000000) { \ (x).tv_usec -= 1000000; \ (x).tv_sec += 1; \ } \ } while (0) /* vstream_buf_init - initialize buffer */ static void vstream_buf_init(VBUF *bp, int flags) { /* * Initialize the buffer such that the first data access triggers a * buffer boundary action. */ VSTREAM_BUF_ZERO(bp); VSTREAM_BUF_ACTIONS(bp, VSTREAM_CAN_READ(flags) ? vstream_buf_get_ready : 0, VSTREAM_CAN_WRITE(flags) ? vstream_buf_put_ready : 0, vstream_buf_space); } /* vstream_buf_alloc - allocate buffer memory */ static void vstream_buf_alloc(VBUF *bp, ssize_t len) { VSTREAM *stream = VBUF_TO_APPL(bp, VSTREAM, buf); ssize_t used = bp->ptr - bp->data; const char *myname = "vstream_buf_alloc"; if (len < bp->len) msg_panic("%s: attempt to shrink buffer", myname); if (bp->flags & VSTREAM_FLAG_FIXED) msg_panic("%s: unable to extend fixed-size buffer", myname); /* * Late buffer allocation allows the user to override the default policy. * If a buffer already exists, allow for the presence of (output) data. */ bp->data = (unsigned char *) (bp->data ? myrealloc((char *) bp->data, len) : mymalloc(len)); bp->len = len; if (bp->flags & VSTREAM_FLAG_READ) { bp->ptr = bp->data + used; if (bp->flags & VSTREAM_FLAG_DOUBLE) VSTREAM_SAVE_STATE(stream, read_buf, read_fd); } else { VSTREAM_BUF_AT_OFFSET(bp, used); if (bp->flags & VSTREAM_FLAG_DOUBLE) VSTREAM_SAVE_STATE(stream, write_buf, write_fd); } } /* vstream_buf_wipe - reset buffer to initial state */ static void vstream_buf_wipe(VBUF *bp) { if ((bp->flags & VBUF_FLAG_FIXED) == 0 && bp->data) myfree((char *) bp->data); VSTREAM_BUF_ZERO(bp); VSTREAM_BUF_ACTIONS(bp, 0, 0, 0); } /* vstream_fflush_some - flush some buffered data */ static int vstream_fflush_some(VSTREAM *stream, ssize_t to_flush) { const char *myname = "vstream_fflush_some"; VBUF *bp = &stream->buf; ssize_t used; ssize_t left_over; char *data; ssize_t len; ssize_t n; int timeout; struct timeval before; struct timeval elapsed; /* * Sanity checks. It is illegal to flush a read-only stream. Otherwise, * if there is buffered input, discard the input. If there is buffered * output, require that the amount to flush is larger than the amount to * keep, so that we can memcpy() the residue. */ if (bp->put_ready == 0) msg_panic("%s: read-only stream", myname); switch (bp->flags & (VSTREAM_FLAG_WRITE | VSTREAM_FLAG_READ)) { case VSTREAM_FLAG_READ: /* discard input */ VSTREAM_BUF_AT_END(bp); /* FALLTHROUGH */ case 0: /* flush after seek? */ return ((bp->flags & VSTREAM_FLAG_ERR) ? VSTREAM_EOF : 0); case VSTREAM_FLAG_WRITE: /* output buffered */ break; case VSTREAM_FLAG_WRITE | VSTREAM_FLAG_READ: msg_panic("%s: read/write stream", myname); } used = bp->len - bp->cnt; left_over = used - to_flush; if (msg_verbose > 2 && stream != VSTREAM_ERR) msg_info("%s: fd %d flush %ld", myname, stream->fd, (long) to_flush); if (to_flush < 0 || left_over < 0) msg_panic("%s: bad to_flush %ld", myname, (long) to_flush); if (to_flush < left_over) msg_panic("%s: to_flush < left_over", myname); if (to_flush == 0) return ((bp->flags & VSTREAM_FLAG_ERR) ? VSTREAM_EOF : 0); if (bp->flags & VSTREAM_FLAG_ERR) return (VSTREAM_EOF); /* * When flushing a buffer, allow for partial writes. These can happen * while talking to a network. Update the cached file seek position, if * any. * * When deadlines are enabled, we count the elapsed time for each write * operation instead of simply comparing the time-of-day clock with a * per-stream deadline. The latter could result in anomalies when an * application does lengthy processing between write operations. Keep in * mind that a receiver may not be able to keep up when a sender suddenly * floods it with a lot of data as it tries to catch up with a deadline. */ for (data = (char *) bp->data, len = to_flush; len > 0; len -= n, data += n) { if (bp->flags & VSTREAM_FLAG_DEADLINE) { timeout = stream->time_limit.tv_sec + (stream->time_limit.tv_usec > 0); if (timeout <= 0) { bp->flags |= (VSTREAM_FLAG_WR_ERR | VSTREAM_FLAG_WR_TIMEOUT); errno = ETIMEDOUT; return (VSTREAM_EOF); } if (len == to_flush) GETTIMEOFDAY(&before); else before = stream->iotime; } else timeout = stream->timeout; if ((n = stream->write_fn(stream->fd, data, len, timeout, stream->context)) <= 0) { bp->flags |= VSTREAM_FLAG_WR_ERR; if (errno == ETIMEDOUT) { bp->flags |= VSTREAM_FLAG_WR_TIMEOUT; stream->time_limit.tv_sec = stream->time_limit.tv_usec = 0; } return (VSTREAM_EOF); } if (timeout) { GETTIMEOFDAY(&stream->iotime); if (bp->flags & VSTREAM_FLAG_DEADLINE) { VSTREAM_SUB_TIME(elapsed, stream->iotime, before); VSTREAM_SUB_TIME(stream->time_limit, stream->time_limit, elapsed); } } if (msg_verbose > 2 && stream != VSTREAM_ERR && n != to_flush) msg_info("%s: %d flushed %ld/%ld", myname, stream->fd, (long) n, (long) to_flush); } if (bp->flags & VSTREAM_FLAG_SEEK) stream->offset += to_flush; /* * Allow for partial buffer flush requests. We use memcpy() for reasons * of portability to pre-ANSI environments (SunOS 4.x or Ultrix 4.x :-). * This is OK because we have already verified that the to_flush count is * larger than the left_over count. */ if (left_over > 0) memcpy(bp->data, bp->data + to_flush, left_over); bp->cnt += to_flush; bp->ptr -= to_flush; return ((bp->flags & VSTREAM_FLAG_ERR) ? VSTREAM_EOF : 0); } /* vstream_fflush_delayed - delayed stream flush for double-buffered stream */ static int vstream_fflush_delayed(VSTREAM *stream) { int status; /* * Sanity check. */ if ((stream->buf.flags & VSTREAM_FLAG_READ_DOUBLE) != VSTREAM_FLAG_READ_DOUBLE) msg_panic("vstream_fflush_delayed: bad flags"); /* * Temporarily swap buffers and flush unwritten data. This may seem like * a lot of work, but it's peanuts compared to the write(2) call that we * already have avoided. For example, delayed flush is never used on a * non-pipelined SMTP connection. */ stream->buf.flags &= ~VSTREAM_FLAG_READ; VSTREAM_SAVE_STATE(stream, read_buf, read_fd); stream->buf.flags |= VSTREAM_FLAG_WRITE; VSTREAM_RESTORE_STATE(stream, write_buf, write_fd); status = VSTREAM_FFLUSH_SOME(stream); stream->buf.flags &= ~VSTREAM_FLAG_WRITE; VSTREAM_SAVE_STATE(stream, write_buf, write_fd); stream->buf.flags |= VSTREAM_FLAG_READ; VSTREAM_RESTORE_STATE(stream, read_buf, read_fd); return (status); } /* vstream_buf_get_ready - vbuf callback to make buffer ready for reading */ static int vstream_buf_get_ready(VBUF *bp) { VSTREAM *stream = VBUF_TO_APPL(bp, VSTREAM, buf); const char *myname = "vstream_buf_get_ready"; ssize_t n; struct timeval before; struct timeval elapsed; int timeout; /* * Detect a change of I/O direction or position. If so, flush any * unwritten output immediately when the stream is single-buffered, or * when the stream is double-buffered and the read buffer is empty. */ switch (bp->flags & (VSTREAM_FLAG_WRITE | VSTREAM_FLAG_READ)) { case VSTREAM_FLAG_WRITE: /* change direction */ if (bp->ptr > bp->data) if ((bp->flags & VSTREAM_FLAG_DOUBLE) == 0 || stream->read_buf.cnt >= 0) if (VSTREAM_FFLUSH_SOME(stream)) return (VSTREAM_EOF); bp->flags &= ~VSTREAM_FLAG_WRITE; if (bp->flags & VSTREAM_FLAG_DOUBLE) VSTREAM_SAVE_STATE(stream, write_buf, write_fd); /* FALLTHROUGH */ case 0: /* change position */ bp->flags |= VSTREAM_FLAG_READ; if (bp->flags & VSTREAM_FLAG_DOUBLE) { VSTREAM_RESTORE_STATE(stream, read_buf, read_fd); if (bp->cnt < 0) return (0); } /* FALLTHROUGH */ case VSTREAM_FLAG_READ: /* no change */ break; case VSTREAM_FLAG_WRITE | VSTREAM_FLAG_READ: msg_panic("%s: read/write stream", myname); } /* * If this is the first GET operation, allocate a buffer. Late buffer * allocation gives the application a chance to override the default * buffering policy. */ if (bp->len < stream->req_bufsize) vstream_buf_alloc(bp, stream->req_bufsize); /* * If the stream is double-buffered and the write buffer is not empty, * this is the time to flush the write buffer. Delayed flushes reduce * system call overhead, and on TCP sockets, avoid triggering Nagle's * algorithm. */ if ((bp->flags & VSTREAM_FLAG_DOUBLE) && stream->write_buf.len > stream->write_buf.cnt) if (vstream_fflush_delayed(stream)) return (VSTREAM_EOF); /* * Did we receive an EOF indication? */ if (bp->flags & VSTREAM_FLAG_EOF) return (VSTREAM_EOF); /* * Fill the buffer with as much data as we can handle, or with as much * data as is available right now, whichever is less. Update the cached * file seek position, if any. * * When deadlines are enabled, we count the elapsed time for each read * operation instead of simply comparing the time-of-day clock with a * per-stream deadline. The latter could result in anomalies when an * application does lengthy processing between read operations. Keep in * mind that a sender may get blocked, and may not be able to keep up * when a receiver suddenly wants to read a lot of data as it tries to * catch up with a deadline. */ if (bp->flags & VSTREAM_FLAG_DEADLINE) { timeout = stream->time_limit.tv_sec + (stream->time_limit.tv_usec > 0); if (timeout <= 0) { bp->flags |= (VSTREAM_FLAG_RD_ERR | VSTREAM_FLAG_RD_TIMEOUT); errno = ETIMEDOUT; return (VSTREAM_EOF); } GETTIMEOFDAY(&before); } else timeout = stream->timeout; switch (n = stream->read_fn(stream->fd, bp->data, bp->len, timeout, stream->context)) { case -1: bp->flags |= VSTREAM_FLAG_RD_ERR; if (errno == ETIMEDOUT) { bp->flags |= VSTREAM_FLAG_RD_TIMEOUT; stream->time_limit.tv_sec = stream->time_limit.tv_usec = 0; } return (VSTREAM_EOF); case 0: bp->flags |= VSTREAM_FLAG_EOF; return (VSTREAM_EOF); default: if (timeout) { GETTIMEOFDAY(&stream->iotime); if (bp->flags & VSTREAM_FLAG_DEADLINE) { VSTREAM_SUB_TIME(elapsed, stream->iotime, before); VSTREAM_SUB_TIME(stream->time_limit, stream->time_limit, elapsed); } } if (msg_verbose > 2) msg_info("%s: fd %d got %ld", myname, stream->fd, (long) n); bp->cnt = -n; bp->ptr = bp->data; if (bp->flags & VSTREAM_FLAG_SEEK) stream->offset += n; return (0); } } /* vstream_buf_put_ready - vbuf callback to make buffer ready for writing */ static int vstream_buf_put_ready(VBUF *bp) { VSTREAM *stream = VBUF_TO_APPL(bp, VSTREAM, buf); const char *myname = "vstream_buf_put_ready"; /* * Sanity checks. Detect a change of I/O direction or position. If so, * discard unread input, and reset the buffer to the beginning. */ switch (bp->flags & (VSTREAM_FLAG_WRITE | VSTREAM_FLAG_READ)) { case VSTREAM_FLAG_READ: /* change direction */ bp->flags &= ~VSTREAM_FLAG_READ; if (bp->flags & VSTREAM_FLAG_DOUBLE) VSTREAM_SAVE_STATE(stream, read_buf, read_fd); /* FALLTHROUGH */ case 0: /* change position */ bp->flags |= VSTREAM_FLAG_WRITE; if (bp->flags & VSTREAM_FLAG_DOUBLE) VSTREAM_RESTORE_STATE(stream, write_buf, write_fd); else VSTREAM_BUF_AT_START(bp); /* FALLTHROUGH */ case VSTREAM_FLAG_WRITE: /* no change */ break; case VSTREAM_FLAG_WRITE | VSTREAM_FLAG_READ: msg_panic("%s: read/write stream", myname); } /* * Remember the direction. If this is the first PUT operation for this * stream or if the buffer is smaller than the requested size, allocate a * new buffer; obviously there is no data to be flushed yet. Otherwise, * flush the buffer. */ if (bp->len < stream->req_bufsize) { vstream_buf_alloc(bp, stream->req_bufsize); } else if (bp->cnt <= 0) { if (VSTREAM_FFLUSH_SOME(stream)) return (VSTREAM_EOF); } return (0); } /* vstream_buf_space - reserve space ahead of time */ static int vstream_buf_space(VBUF *bp, ssize_t want) { VSTREAM *stream = VBUF_TO_APPL(bp, VSTREAM, buf); ssize_t used; ssize_t incr; ssize_t shortage; const char *myname = "vstream_buf_space"; /* * Sanity checks. Reserving space implies writing. It is illegal to write * to a read-only stream. Detect a change of I/O direction or position. * If so, reset the buffer to the beginning. */ if (bp->put_ready == 0) msg_panic("%s: read-only stream", myname); switch (bp->flags & (VSTREAM_FLAG_READ | VSTREAM_FLAG_WRITE)) { case VSTREAM_FLAG_READ: /* change direction */ bp->flags &= ~VSTREAM_FLAG_READ; if (bp->flags & VSTREAM_FLAG_DOUBLE) VSTREAM_SAVE_STATE(stream, read_buf, read_fd); /* FALLTHROUGH */ case 0: /* change position */ bp->flags |= VSTREAM_FLAG_WRITE; if (bp->flags & VSTREAM_FLAG_DOUBLE) VSTREAM_RESTORE_STATE(stream, write_buf, write_fd); else VSTREAM_BUF_AT_START(bp); /* FALLTHROUGH */ case VSTREAM_FLAG_WRITE: /* no change */ break; case VSTREAM_FLAG_READ | VSTREAM_FLAG_WRITE: msg_panic("%s: read/write stream", myname); } /* * See if enough space is available. If not, flush a multiple of * VSTREAM_BUFSIZE bytes and resize the buffer to a multiple of * VSTREAM_BUFSIZE. We flush multiples of VSTREAM_BUFSIZE in an attempt * to keep file updates block-aligned for better performance. */ #define VSTREAM_TRUNCATE(count, base) (((count) / (base)) * (base)) #define VSTREAM_ROUNDUP(count, base) VSTREAM_TRUNCATE(count + base - 1, base) if (want > bp->cnt) { if ((used = bp->len - bp->cnt) > stream->req_bufsize) if (vstream_fflush_some(stream, VSTREAM_TRUNCATE(used, stream->req_bufsize))) return (VSTREAM_EOF); if ((shortage = (want - bp->cnt)) > 0) { if ((bp->flags & VSTREAM_FLAG_FIXED) || shortage > __MAXINT__(ssize_t) -bp->len - stream->req_bufsize) { bp->flags |= VSTREAM_FLAG_WR_ERR; } else { incr = VSTREAM_ROUNDUP(shortage, stream->req_bufsize); vstream_buf_alloc(bp, bp->len + incr); } } } return (vstream_ferror(stream) ? VSTREAM_EOF : 0); /* mmap() may fail */ } /* vstream_fpurge - discard unread or unwritten content */ int vstream_fpurge(VSTREAM *stream, int direction) { const char *myname = "vstream_fpurge"; VBUF *bp = &stream->buf; #define VSTREAM_MAYBE_PURGE_WRITE(d, b) if ((d) & VSTREAM_PURGE_WRITE) \ VSTREAM_BUF_AT_START((b)) #define VSTREAM_MAYBE_PURGE_READ(d, b) if ((d) & VSTREAM_PURGE_READ) \ VSTREAM_BUF_AT_END((b)) /* * To discard all unread contents, position the read buffer at its end, * so that we skip over any unread data, and so that the next read * operation will refill the buffer. * * To discard all unwritten content, position the write buffer at its * beginning, so that the next write operation clobbers any unwritten * data. */ switch (bp->flags & (VSTREAM_FLAG_READ_DOUBLE | VSTREAM_FLAG_WRITE)) { case VSTREAM_FLAG_READ_DOUBLE: VSTREAM_MAYBE_PURGE_WRITE(direction, &stream->write_buf); /* FALLTHROUGH */ case VSTREAM_FLAG_READ: VSTREAM_MAYBE_PURGE_READ(direction, bp); break; case VSTREAM_FLAG_DOUBLE: VSTREAM_MAYBE_PURGE_WRITE(direction, &stream->write_buf); VSTREAM_MAYBE_PURGE_READ(direction, &stream->read_buf); break; case VSTREAM_FLAG_WRITE_DOUBLE: VSTREAM_MAYBE_PURGE_READ(direction, &stream->read_buf); /* FALLTHROUGH */ case VSTREAM_FLAG_WRITE: VSTREAM_MAYBE_PURGE_WRITE(direction, bp); break; case VSTREAM_FLAG_READ_DOUBLE | VSTREAM_FLAG_WRITE: case VSTREAM_FLAG_READ | VSTREAM_FLAG_WRITE: msg_panic("%s: read/write stream", myname); } /* * Invalidate the cached file seek position. */ bp->flags &= ~VSTREAM_FLAG_SEEK; stream->offset = 0; return (0); } /* vstream_fseek - change I/O position */ off_t vstream_fseek(VSTREAM *stream, off_t offset, int whence) { const char *myname = "vstream_fseek"; VBUF *bp = &stream->buf; /* * Flush any unwritten output. Discard any unread input. Position the * buffer at the end, so that the next GET or PUT operation triggers a * buffer boundary action. */ switch (bp->flags & (VSTREAM_FLAG_READ | VSTREAM_FLAG_WRITE)) { case VSTREAM_FLAG_WRITE: if (bp->ptr > bp->data) { if (whence == SEEK_CUR) offset += (bp->ptr - bp->data); /* add unwritten data */ else if (whence == SEEK_END) bp->flags &= ~VSTREAM_FLAG_SEEK; if (VSTREAM_FFLUSH_SOME(stream)) return (-1); } VSTREAM_BUF_AT_END(bp); break; case VSTREAM_FLAG_READ: if (whence == SEEK_CUR) offset += bp->cnt; /* subtract unread data */ else if (whence == SEEK_END) bp->flags &= ~VSTREAM_FLAG_SEEK; /* FALLTHROUGH */ case 0: VSTREAM_BUF_AT_END(bp); break; case VSTREAM_FLAG_READ | VSTREAM_FLAG_WRITE: msg_panic("%s: read/write stream", myname); } /* * Clear the read/write flags to inform the buffer boundary action * routines that we may have changed I/O position. */ bp->flags &= ~(VSTREAM_FLAG_READ | VSTREAM_FLAG_WRITE); /* * Shave an unnecessary system call. */ if (bp->flags & VSTREAM_FLAG_NSEEK) { errno = ESPIPE; return (-1); } /* * Update the cached file seek position. */ if ((stream->offset = lseek(stream->fd, offset, whence)) < 0) { if (errno == ESPIPE) bp->flags |= VSTREAM_FLAG_NSEEK; } else { bp->flags |= VSTREAM_FLAG_SEEK; } bp->flags &= ~VSTREAM_FLAG_EOF; return (stream->offset); } /* vstream_ftell - return file offset */ off_t vstream_ftell(VSTREAM *stream) { VBUF *bp = &stream->buf; /* * Shave an unnecessary syscall. */ if (bp->flags & VSTREAM_FLAG_NSEEK) { errno = ESPIPE; return (-1); } /* * Use the cached file offset when available. This is the offset after * the last read, write or seek operation. */ if ((bp->flags & VSTREAM_FLAG_SEEK) == 0) { if ((stream->offset = lseek(stream->fd, (off_t) 0, SEEK_CUR)) < 0) { bp->flags |= VSTREAM_FLAG_NSEEK; return (-1); } bp->flags |= VSTREAM_FLAG_SEEK; } /* * If this is a read buffer, subtract the number of unread bytes from the * cached offset. Remember that read counts are negative. */ if (bp->flags & VSTREAM_FLAG_READ) return (stream->offset + bp->cnt); /* * If this is a write buffer, add the number of unwritten bytes to the * cached offset. */ if (bp->flags & VSTREAM_FLAG_WRITE) return (stream->offset + (bp->ptr - bp->data)); /* * Apparently, this is a new buffer, or a buffer after seek, so there is * no need to account for unread or unwritten data. */ return (stream->offset); } /* vstream_fdopen - add buffering to pre-opened stream */ VSTREAM *vstream_fdopen(int fd, int flags) { VSTREAM *stream; /* * Sanity check. */ if (fd < 0) msg_panic("vstream_fdopen: bad file %d", fd); /* * Initialize buffers etc. but do as little as possible. Late buffer * allocation etc. gives the application a chance to override default * policies. Either this, or the vstream*open() routines would have to * have a really ugly interface with lots of mostly-unused arguments (can * you say VMS?). */ stream = (VSTREAM *) mymalloc(sizeof(*stream)); stream->fd = fd; stream->read_fn = VSTREAM_CAN_READ(flags) ? (VSTREAM_FN) timed_read : 0; stream->write_fn = VSTREAM_CAN_WRITE(flags) ? (VSTREAM_FN) timed_write : 0; vstream_buf_init(&stream->buf, flags); stream->offset = 0; stream->path = 0; stream->pid = 0; stream->waitpid_fn = 0; stream->timeout = 0; stream->context = 0; stream->jbuf = 0; stream->iotime.tv_sec = stream->iotime.tv_usec = 0; stream->time_limit.tv_sec = stream->time_limit.tv_usec = 0; stream->req_bufsize = VSTREAM_BUFSIZE; return (stream); } /* vstream_fopen - open buffered file stream */ VSTREAM *vstream_fopen(const char *path, int flags, mode_t mode) { VSTREAM *stream; int fd; if ((fd = open(path, flags, mode)) < 0) { return (0); } else { stream = vstream_fdopen(fd, flags); stream->path = mystrdup(path); return (stream); } } /* vstream_fflush - flush write buffer */ int vstream_fflush(VSTREAM *stream) { if ((stream->buf.flags & VSTREAM_FLAG_READ_DOUBLE) == VSTREAM_FLAG_READ_DOUBLE && stream->write_buf.len > stream->write_buf.cnt) vstream_fflush_delayed(stream); return (VSTREAM_FFLUSH_SOME(stream)); } /* vstream_fclose - close buffered stream */ int vstream_fclose(VSTREAM *stream) { int err; /* * NOTE: Negative file descriptors are not part of the external * interface. They are for internal use only, in order to support * vstream_fdclose() without a lot of code duplication. Applications that * rely on negative VSTREAM file descriptors will break without warning. */ if (stream->pid != 0) msg_panic("vstream_fclose: stream has process"); if ((stream->buf.flags & VSTREAM_FLAG_WRITE_DOUBLE) != 0 && stream->fd >= 0) vstream_fflush(stream); /* Do not remove: vstream_fdclose() depends on this error test. */ err = vstream_ferror(stream); if (stream->buf.flags & VSTREAM_FLAG_DOUBLE) { if (stream->read_fd >= 0) err |= close(stream->read_fd); if (stream->write_fd != stream->read_fd) if (stream->write_fd >= 0) err |= close(stream->write_fd); vstream_buf_wipe(&stream->read_buf); vstream_buf_wipe(&stream->write_buf); stream->buf = stream->read_buf; } else { if (stream->fd >= 0) err |= close(stream->fd); vstream_buf_wipe(&stream->buf); } if (stream->path) myfree(stream->path); if (stream->jbuf) myfree((char *) stream->jbuf); if (!VSTREAM_STATIC(stream)) myfree((char *) stream); return (err ? VSTREAM_EOF : 0); } /* vstream_fdclose - close stream, leave file(s) open */ int vstream_fdclose(VSTREAM *stream) { /* * Flush unwritten output, just like vstream_fclose(). Errors are * reported by vstream_fclose(). */ if ((stream->buf.flags & VSTREAM_FLAG_WRITE_DOUBLE) != 0) (void) vstream_fflush(stream); /* * NOTE: Negative file descriptors are not part of the external * interface. They are for internal use only, in order to support * vstream_fdclose() without a lot of code duplication. Applications that * rely on negative VSTREAM file descriptors will break without warning. */ if (stream->buf.flags & VSTREAM_FLAG_DOUBLE) { stream->fd = stream->read_fd = stream->write_fd = -1; } else { stream->fd = -1; } return (vstream_fclose(stream)); } /* vstream_printf - formatted print to stdout */ VSTREAM *vstream_printf(const char *fmt,...) { VSTREAM *stream = VSTREAM_OUT; va_list ap; va_start(ap, fmt); vbuf_print(&stream->buf, fmt, ap); va_end(ap); return (stream); } /* vstream_fprintf - formatted print to buffered stream */ VSTREAM *vstream_fprintf(VSTREAM *stream, const char *fmt,...) { va_list ap; va_start(ap, fmt); vbuf_print(&stream->buf, fmt, ap); va_end(ap); return (stream); } /* vstream_fputs - write string to stream */ int vstream_fputs(const char *str, VSTREAM *stream) { int ch; while ((ch = *str++) != 0) if (VSTREAM_PUTC(ch, stream) == VSTREAM_EOF) return (VSTREAM_EOF); return (0); } /* vstream_control - fine control */ void vstream_control(VSTREAM *stream, int name,...) { const char *myname = "vstream_control"; va_list ap; int floor; int old_fd; ssize_t req_bufsize = 0; VSTREAM *stream2; #define SWAP(type,a,b) do { type temp = (a); (a) = (b); (b) = (temp); } while (0) for (va_start(ap, name); name != VSTREAM_CTL_END; name = va_arg(ap, int)) { switch (name) { case VSTREAM_CTL_READ_FN: stream->read_fn = va_arg(ap, VSTREAM_FN); break; case VSTREAM_CTL_WRITE_FN: stream->write_fn = va_arg(ap, VSTREAM_FN); break; case VSTREAM_CTL_CONTEXT: stream->context = va_arg(ap, char *); break; /* APPLE - RFC 3030 */ case VSTREAM_CTL_CONTEXT_GET: *(va_arg(ap, char **)) = stream->context; break; case VSTREAM_CTL_PATH: if (stream->path) myfree(stream->path); stream->path = mystrdup(va_arg(ap, char *)); break; case VSTREAM_CTL_DOUBLE: if ((stream->buf.flags & VSTREAM_FLAG_DOUBLE) == 0) { stream->buf.flags |= VSTREAM_FLAG_DOUBLE; if (stream->buf.flags & VSTREAM_FLAG_READ) { VSTREAM_SAVE_STATE(stream, read_buf, read_fd); VSTREAM_FORK_STATE(stream, write_buf, write_fd); } else { VSTREAM_SAVE_STATE(stream, write_buf, write_fd); VSTREAM_FORK_STATE(stream, read_buf, read_fd); } } break; case VSTREAM_CTL_READ_FD: if ((stream->buf.flags & VSTREAM_FLAG_DOUBLE) == 0) msg_panic("VSTREAM_CTL_READ_FD requires double buffering"); stream->read_fd = va_arg(ap, int); stream->buf.flags |= VSTREAM_FLAG_NSEEK; break; case VSTREAM_CTL_WRITE_FD: if ((stream->buf.flags & VSTREAM_FLAG_DOUBLE) == 0) msg_panic("VSTREAM_CTL_WRITE_FD requires double buffering"); stream->write_fd = va_arg(ap, int); stream->buf.flags |= VSTREAM_FLAG_NSEEK; break; case VSTREAM_CTL_SWAP_FD: stream2 = va_arg(ap, VSTREAM *); if ((stream->buf.flags & VSTREAM_FLAG_DOUBLE) != (stream2->buf.flags & VSTREAM_FLAG_DOUBLE)) msg_panic("VSTREAM_CTL_SWAP_FD can't swap descriptors between " "single-buffered and double-buffered streams"); if (stream->buf.flags & VSTREAM_FLAG_DOUBLE) { SWAP(int, stream->read_fd, stream2->read_fd); SWAP(int, stream->write_fd, stream2->write_fd); stream->fd = ((stream->buf.flags & VSTREAM_FLAG_WRITE) ? stream->write_fd : stream->read_fd); } else { SWAP(int, stream->fd, stream2->fd); } break; case VSTREAM_CTL_TIMEOUT: if (stream->timeout == 0) GETTIMEOFDAY(&stream->iotime); stream->timeout = va_arg(ap, int); if (stream->timeout < 0) msg_panic("%s: bad timeout %d", myname, stream->timeout); break; case VSTREAM_CTL_EXCEPT: if (stream->jbuf == 0) stream->jbuf = (VSTREAM_JMP_BUF *) mymalloc(sizeof(VSTREAM_JMP_BUF)); break; #ifdef VSTREAM_CTL_DUPFD #define VSTREAM_TRY_DUPFD(backup, fd, floor) do { \ if (((backup) = (fd)) < floor) { \ if (((fd) = fcntl((backup), F_DUPFD, (floor))) < 0) \ msg_fatal("fcntl F_DUPFD %d: %m", (floor)); \ (void) close(backup); \ } \ } while (0) case VSTREAM_CTL_DUPFD: floor = va_arg(ap, int); if (stream->buf.flags & VSTREAM_FLAG_DOUBLE) { VSTREAM_TRY_DUPFD(old_fd, stream->read_fd, floor); if (stream->write_fd == old_fd) stream->write_fd = stream->read_fd; else VSTREAM_TRY_DUPFD(old_fd, stream->write_fd, floor); stream->fd = (stream->buf.flags & VSTREAM_FLAG_READ) ? stream->read_fd : stream->write_fd; } else { VSTREAM_TRY_DUPFD(old_fd, stream->fd, floor); } break; #endif /* * Postpone memory (re)allocation until the space is needed. */ case VSTREAM_CTL_BUFSIZE: req_bufsize = va_arg(ap, ssize_t); if (req_bufsize < 0) msg_panic("VSTREAM_CTL_BUFSIZE with negative size: %ld", (long) req_bufsize); if (stream != VSTREAM_ERR && req_bufsize > stream->req_bufsize) stream->req_bufsize = req_bufsize; break; /* * Make no gettimeofday() etc. system call until we really know * that we need to do I/O. This avoids a performance hit when * sending or receiving body content one line at a time. */ case VSTREAM_CTL_STOP_DEADLINE: stream->buf.flags &= ~VSTREAM_FLAG_DEADLINE; break; case VSTREAM_CTL_START_DEADLINE: if (stream->timeout <= 0) msg_panic("%s: bad timeout %d", myname, stream->timeout); stream->buf.flags |= VSTREAM_FLAG_DEADLINE; stream->time_limit.tv_sec = stream->timeout; stream->time_limit.tv_usec = 0; break; default: msg_panic("%s: bad name %d", myname, name); } } va_end(ap); } /* vstream_vprintf - formatted print to stdout */ VSTREAM *vstream_vprintf(const char *format, va_list ap) { VSTREAM *vp = VSTREAM_OUT; vbuf_print(&vp->buf, format, ap); return (vp); } /* vstream_vfprintf - formatted print engine */ VSTREAM *vstream_vfprintf(VSTREAM *vp, const char *format, va_list ap) { vbuf_print(&vp->buf, format, ap); return (vp); } /* vstream_bufstat - get stream buffer status */ ssize_t vstream_bufstat(VSTREAM *vp, int command) { VBUF *bp; switch (command & VSTREAM_BST_MASK_DIR) { case VSTREAM_BST_FLAG_IN: if (vp->buf.flags & VSTREAM_FLAG_READ) { bp = &vp->buf; } else if (vp->buf.flags & VSTREAM_FLAG_DOUBLE) { bp = &vp->read_buf; } else { bp = 0; } switch (command & ~VSTREAM_BST_MASK_DIR) { case VSTREAM_BST_FLAG_PEND: return (bp ? -bp->cnt : 0); /* Add other requests below. */ } break; case VSTREAM_BST_FLAG_OUT: if (vp->buf.flags & VSTREAM_FLAG_WRITE) { bp = &vp->buf; } else if (vp->buf.flags & VSTREAM_FLAG_DOUBLE) { bp = &vp->write_buf; } else { bp = 0; } switch (command & ~VSTREAM_BST_MASK_DIR) { case VSTREAM_BST_FLAG_PEND: return (bp ? bp->len - bp->cnt : 0); /* Add other requests below. */ } break; } msg_panic("vstream_bufstat: unknown command: %d", command); } #undef vstream_peek /* API binary compatibility. */ /* vstream_peek - peek at a stream */ ssize_t vstream_peek(VSTREAM *vp) { if (vp->buf.flags & VSTREAM_FLAG_READ) { return (-vp->buf.cnt); } else if (vp->buf.flags & VSTREAM_FLAG_DOUBLE) { return (-vp->read_buf.cnt); } else { return (0); } } /* vstream_peek_data - peek at unread data */ const char *vstream_peek_data(VSTREAM *vp) { if (vp->buf.flags & VSTREAM_FLAG_READ) { return ((const char *) vp->buf.ptr); } else if (vp->buf.flags & VSTREAM_FLAG_DOUBLE) { return ((const char *) vp->read_buf.ptr); } else { return (0); } } /* APPLE - burl and RFC 3030 - rest of file vstream_limit_* don't handle read/write because there's just no need yet */ struct vstream_limit { VSTREAM_FN parent_read_fn; VSTREAM_FN parent_write_fn; void *parent_context; off_t limit; char *overread; unsigned int overread_len; }; static ssize_t vstream_limit_read(int fd, void *buf, size_t len, int timeout, void *context) { struct vstream_limit *lp = (struct vstream_limit *) context; ssize_t r; /* read no more than the limit */ if (lp->limit == 0) return 0; else if (len > lp->limit) len = lp->limit; r = lp->parent_read_fn(fd, buf, len, timeout, lp->parent_context); if (r > 0) lp->limit -= r; return r; } static ssize_t vstream_limit_write(int fd, void *buf, size_t len, int timeout, void *context) { struct vstream_limit *lp = (struct vstream_limit *) context; /* impose no limit on writing, just pass through to parent */ return lp->parent_write_fn(fd, buf, len, timeout, lp->parent_context); } void vstream_limit_init(VSTREAM *stream, off_t limit) { VBUF *bp = &stream->buf; struct vstream_limit *lp; if (limit < 0) msg_panic("vstream_limit_init: negative limit"); lp = (struct vstream_limit *) mymalloc(sizeof *lp); lp->parent_read_fn = stream->read_fn; stream->read_fn = vstream_limit_read; lp->parent_write_fn = stream->write_fn; stream->write_fn = vstream_limit_write; lp->parent_context = stream->context; stream->context = lp; if (bp->cnt > 0 || (bp->flags & VSTREAM_FLAG_READ) == 0) msg_panic("vstream_limit_init with write buffer"); if (-bp->cnt > limit) { /* the stream already has more than the wanted data buffered. save the rest. */ lp->overread_len = -bp->cnt - limit; lp->overread = mymalloc(lp->overread_len); memcpy(lp->overread, bp->ptr + limit, lp->overread_len); lp->limit = 0; bp->cnt = -(ssize_t) limit; } else { /* at most limit bytes buffered. read no more than the remainder */ lp->overread_len = 0; lp->overread = NULL; lp->limit = limit + bp->cnt; } } int vstream_limit_reached(const VSTREAM *stream) { const VBUF *bp = &stream->buf; struct vstream_limit *lp = (struct vstream_limit *) stream->context; return bp->cnt == 0 && lp->limit == 0; } void vstream_limit_deinit(VSTREAM *stream) { VBUF *bp = &stream->buf; struct vstream_limit *lp = (struct vstream_limit *) stream->context; if (bp->cnt > 0 || (bp->flags & VSTREAM_FLAG_READ) == 0) msg_panic("vstream_limit_deinit with write buffer"); if (lp->overread != NULL) { memcpy(bp->data, lp->overread, lp->overread_len); bp->ptr = bp->data; bp->cnt = -(ssize_t) lp->overread_len; myfree(lp->overread); } stream->read_fn = lp->parent_read_fn; stream->write_fn = lp->parent_write_fn; stream->context = lp->parent_context; myfree((char *) lp); }