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-rw-r--r--src/global/record.c415
1 files changed, 415 insertions, 0 deletions
diff --git a/src/global/record.c b/src/global/record.c
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+/*++
+/* NAME
+/* record 3
+/* SUMMARY
+/* simple typed record I/O
+/* SYNOPSIS
+/* #include <record.h>
+/*
+/* int rec_get(stream, buf, maxsize)
+/* VSTREAM *stream;
+/* VSTRING *buf;
+/* ssize_t maxsize;
+/*
+/* int rec_get_raw(stream, buf, maxsize, flags)
+/* VSTREAM *stream;
+/* VSTRING *buf;
+/* ssize_t maxsize;
+/* int flags;
+/*
+/* int rec_put(stream, type, data, len)
+/* VSTREAM *stream;
+/* int type;
+/* const char *data;
+/* ssize_t len;
+/* AUXILIARY FUNCTIONS
+/* int rec_put_type(stream, type, offset)
+/* VSTREAM *stream;
+/* int type;
+/* long offset;
+/*
+/* int rec_fprintf(stream, type, format, ...)
+/* VSTREAM *stream;
+/* int type;
+/* const char *format;
+/*
+/* int rec_fputs(stream, type, str)
+/* VSTREAM *stream;
+/* int type;
+/* const char *str;
+/*
+/* int REC_PUT_BUF(stream, type, buf)
+/* VSTREAM *stream;
+/* int type;
+/* VSTRING *buf;
+/*
+/* int rec_vfprintf(stream, type, format, ap)
+/* VSTREAM *stream;
+/* int type;
+/* const char *format;
+/* va_list ap;
+/*
+/* int rec_goto(stream, where)
+/* VSTREAM *stream;
+/* const char *where;
+/*
+/* int rec_pad(stream, type, len)
+/* VSTREAM *stream;
+/* int type;
+/* ssize_t len;
+/*
+/* REC_SPACE_NEED(buflen, reclen)
+/* ssize_t buflen;
+/* ssize_t reclen;
+/*
+/* REC_GET_HIDDEN_TYPE(type)
+/* int type;
+/* DESCRIPTION
+/* This module reads and writes typed variable-length records.
+/* Each record contains a 1-byte type code (0..255), a length
+/* (1 or more bytes) and as much data as the length specifies.
+/*
+/* rec_get_raw() retrieves a record from the named record stream
+/* and returns the record type. The \fImaxsize\fR argument is
+/* zero, or specifies a maximal acceptable record length.
+/* The result is REC_TYPE_EOF when the end of the file was reached,
+/* and REC_TYPE_ERROR in case of a bad record. The result buffer is
+/* null-terminated for convenience. Records may contain embedded
+/* null characters. The \fIflags\fR argument specifies zero or
+/* more of the following:
+/* .IP REC_FLAG_FOLLOW_PTR
+/* Follow PTR records, instead of exposing them to the application.
+/* .IP REC_FLAG_SKIP_DTXT
+/* Skip "deleted text" records, instead of exposing them to
+/* the application.
+/* .IP REC_FLAG_SEEK_END
+/* Seek to the end-of-file upon reading a REC_TYPE_END record.
+/* .PP
+/* Specify REC_FLAG_NONE to request no special processing,
+/* and REC_FLAG_DEFAULT for normal use.
+/*
+/* rec_get() is a wrapper around rec_get_raw() that always
+/* enables the REC_FLAG_FOLLOW_PTR, REC_FLAG_SKIP_DTXT
+/* and REC_FLAG_SEEK_END features.
+/*
+/* REC_GET_HIDDEN_TYPE() is an unsafe macro that returns
+/* non-zero when the specified record type is "not exposed"
+/* by rec_get().
+/*
+/* rec_put() stores the specified record and returns the record
+/* type, or REC_TYPE_ERROR in case of problems.
+/*
+/* rec_put_type() updates the type field of the record at the
+/* specified file offset. The result is the new record type,
+/* or REC_TYPE_ERROR in case of trouble.
+/*
+/* rec_fprintf() and rec_vfprintf() format their arguments and
+/* write the result to the named stream. The result is the same
+/* as with rec_put().
+/*
+/* rec_fputs() writes a record with as contents a copy of the
+/* specified string. The result is the same as with rec_put().
+/*
+/* REC_PUT_BUF() is a wrapper for rec_put() that makes it
+/* easier to handle VSTRING buffers. It is an unsafe macro
+/* that evaluates some arguments more than once.
+/*
+/* rec_goto() takes the argument of a pointer record and moves
+/* the file pointer to the specified location. A zero position
+/* means do nothing. The result is REC_TYPE_ERROR in case of
+/* failure.
+/*
+/* rec_pad() writes a record that occupies the larger of (the
+/* specified amount) or (an implementation-defined minimum).
+/*
+/* REC_SPACE_NEED(buflen, reclen) converts the specified buffer
+/* length into a record length. This macro modifies its second
+/* argument.
+/* DIAGNOSTICS
+/* Panics: interface violations. Fatal errors: insufficient memory.
+/* Warnings: corrupted file.
+/* 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
+/*
+/* Wietse Venema
+/* Google, Inc.
+/* 111 8th Avenue
+/* New York, NY 10011, USA
+/*--*/
+
+/* System library. */
+
+#include <sys_defs.h>
+#include <stdlib.h> /* 44BSD stdarg.h uses abort() */
+#include <stdarg.h>
+#include <unistd.h>
+#include <string.h>
+
+#ifndef NBBY
+#define NBBY 8 /* XXX should be in sys_defs.h */
+#endif
+
+/* Utility library. */
+
+#include <msg.h>
+#include <mymalloc.h>
+#include <vstream.h>
+#include <vstring.h>
+#include <stringops.h>
+
+/* Global library. */
+
+#include <off_cvt.h>
+#include <rec_type.h>
+#include <record.h>
+
+/* rec_put_type - update record type field */
+
+int rec_put_type(VSTREAM *stream, int type, off_t offset)
+{
+ if (type < 0 || type > 255)
+ msg_panic("rec_put_type: bad record type %d", type);
+
+ if (msg_verbose > 2)
+ msg_info("rec_put_type: %d at %ld", type, (long) offset);
+
+ if (vstream_fseek(stream, offset, SEEK_SET) < 0
+ || VSTREAM_PUTC(type, stream) != type) {
+ msg_warn("%s: seek or write error", VSTREAM_PATH(stream));
+ return (REC_TYPE_ERROR);
+ } else {
+ return (type);
+ }
+}
+
+/* rec_put - store typed record */
+
+int rec_put(VSTREAM *stream, int type, const char *data, ssize_t len)
+{
+ ssize_t len_rest;
+ int len_byte;
+
+ if (type < 0 || type > 255)
+ msg_panic("rec_put: bad record type %d", type);
+
+ if (msg_verbose > 2)
+ msg_info("rec_put: type %c len %ld data %.10s",
+ type, (long) len, data);
+
+ /*
+ * Write the record type, one byte.
+ */
+ if (VSTREAM_PUTC(type, stream) == VSTREAM_EOF)
+ return (REC_TYPE_ERROR);
+
+ /*
+ * Write the record data length in 7-bit portions, using the 8th bit to
+ * indicate that there is more. Use as many length bytes as needed.
+ */
+ len_rest = len;
+ do {
+ len_byte = len_rest & 0177;
+ if (len_rest >>= 7U)
+ len_byte |= 0200;
+ if (VSTREAM_PUTC(len_byte, stream) == VSTREAM_EOF) {
+ return (REC_TYPE_ERROR);
+ }
+ } while (len_rest != 0);
+
+ /*
+ * Write the record data portion. Use as many length bytes as needed.
+ */
+ if (len && vstream_fwrite(stream, data, len) != len)
+ return (REC_TYPE_ERROR);
+ return (type);
+}
+
+/* rec_get_raw - retrieve typed record */
+
+int rec_get_raw(VSTREAM *stream, VSTRING *buf, ssize_t maxsize, int flags)
+{
+ const char *myname = "rec_get";
+ int type;
+ ssize_t len;
+ int len_byte;
+ unsigned shift;
+
+ /*
+ * Sanity check.
+ */
+ if (maxsize < 0)
+ msg_panic("%s: bad record size limit: %ld", myname, (long) maxsize);
+
+ for (;;) {
+
+ /*
+ * Extract the record type.
+ */
+ if ((type = VSTREAM_GETC(stream)) == VSTREAM_EOF)
+ return (REC_TYPE_EOF);
+
+ /*
+ * Find out the record data length. Return an error result when the
+ * record data length is malformed or when it exceeds the acceptable
+ * limit.
+ */
+ for (len = 0, shift = 0; /* void */ ; shift += 7) {
+ if (shift >= (int) (NBBY * sizeof(int))) {
+ msg_warn("%s: too many length bits, record type %d",
+ VSTREAM_PATH(stream), type);
+ return (REC_TYPE_ERROR);
+ }
+ if ((len_byte = VSTREAM_GETC(stream)) == VSTREAM_EOF) {
+ msg_warn("%s: unexpected EOF reading length, record type %d",
+ VSTREAM_PATH(stream), type);
+ return (REC_TYPE_ERROR);
+ }
+ len |= (len_byte & 0177) << shift;
+ if ((len_byte & 0200) == 0)
+ break;
+ }
+ if (len < 0 || (maxsize > 0 && len > maxsize)) {
+ msg_warn("%s: illegal length %ld, record type %d",
+ VSTREAM_PATH(stream), (long) len, type);
+ while (len-- > 0 && VSTREAM_GETC(stream) != VSTREAM_EOF)
+ /* void */ ;
+ return (REC_TYPE_ERROR);
+ }
+
+ /*
+ * Reserve buffer space for the result, and read the record data into
+ * the buffer.
+ */
+ if (vstream_fread_buf(stream, buf, len) != len) {
+ msg_warn("%s: unexpected EOF in data, record type %d length %ld",
+ VSTREAM_PATH(stream), type, (long) len);
+ return (REC_TYPE_ERROR);
+ }
+ VSTRING_TERMINATE(buf);
+ if (msg_verbose > 2)
+ msg_info("%s: type %c len %ld data %.10s", myname,
+ type, (long) len, vstring_str(buf));
+
+ /*
+ * Transparency options.
+ */
+ if (flags == 0)
+ break;
+ if (type == REC_TYPE_PTR && (flags & REC_FLAG_FOLLOW_PTR) != 0
+ && (type = rec_goto(stream, vstring_str(buf))) != REC_TYPE_ERROR)
+ continue;
+ if (type == REC_TYPE_DTXT && (flags & REC_FLAG_SKIP_DTXT) != 0)
+ continue;
+ if (type == REC_TYPE_END && (flags & REC_FLAG_SEEK_END) != 0
+ && vstream_fseek(stream, (off_t) 0, SEEK_END) < 0) {
+ msg_warn("%s: seek error after reading END record: %m",
+ VSTREAM_PATH(stream));
+ return (REC_TYPE_ERROR);
+ }
+ break;
+ }
+ return (type);
+}
+
+/* rec_goto - follow PTR record */
+
+int rec_goto(VSTREAM *stream, const char *buf)
+{
+ off_t offset;
+ static char *saved_path;
+ static off_t saved_offset;
+ static int reverse_count;
+
+ /*
+ * Crude workaround for queue file loops. VSTREAMs currently have no
+ * option to attach application-specific data, so we use global state and
+ * simple logic to detect if an application switches streams. We trigger
+ * on reverse jumps only. There's one reverse jump for every inserted
+ * header, but only one reverse jump for all appended recipients. No-one
+ * is likely to insert 10000 message headers, but someone might append
+ * 10000 recipients.
+ */
+#define REVERSE_JUMP_LIMIT 10000
+
+ if (saved_path == 0 || strcmp(saved_path, VSTREAM_PATH(stream)) != 0) {
+ if (saved_path)
+ myfree(saved_path);
+ saved_path = mystrdup(VSTREAM_PATH(stream));
+ reverse_count = 0;
+ saved_offset = 0;
+ }
+ while (ISSPACE(*buf))
+ buf++;
+ if ((offset = off_cvt_string(buf)) < 0) {
+ msg_warn("%s: malformed pointer record value: %s",
+ VSTREAM_PATH(stream), buf);
+ return (REC_TYPE_ERROR);
+ } else if (offset == 0) {
+ /* Dummy record. */
+ return (0);
+ } else if (offset <= saved_offset && ++reverse_count > REVERSE_JUMP_LIMIT) {
+ msg_warn("%s: too many reverse jump records", VSTREAM_PATH(stream));
+ return (REC_TYPE_ERROR);
+ } else if (vstream_fseek(stream, offset, SEEK_SET) < 0) {
+ msg_warn("%s: seek error after pointer record: %m",
+ VSTREAM_PATH(stream));
+ return (REC_TYPE_ERROR);
+ } else {
+ saved_offset = offset;
+ return (0);
+ }
+}
+
+/* rec_vfprintf - write formatted string to record */
+
+int rec_vfprintf(VSTREAM *stream, int type, const char *format, va_list ap)
+{
+ static VSTRING *vp;
+
+ if (vp == 0)
+ vp = vstring_alloc(100);
+
+ /*
+ * Writing a formatted string involves an extra copy, because we must
+ * know the record length before we can write it.
+ */
+ vstring_vsprintf(vp, format, ap);
+ return (REC_PUT_BUF(stream, type, vp));
+}
+
+/* rec_fprintf - write formatted string to record */
+
+int rec_fprintf(VSTREAM *stream, int type, const char *format,...)
+{
+ int result;
+ va_list ap;
+
+ va_start(ap, format);
+ result = rec_vfprintf(stream, type, format, ap);
+ va_end(ap);
+ return (result);
+}
+
+/* rec_fputs - write string to record */
+
+int rec_fputs(VSTREAM *stream, int type, const char *str)
+{
+ return (rec_put(stream, type, str, str ? strlen(str) : 0));
+}
+
+/* rec_pad - write padding record */
+
+int rec_pad(VSTREAM *stream, int type, ssize_t len)
+{
+ int width = len - 2; /* type + length */
+
+ return (rec_fprintf(stream, type, "%*s",
+ width < 1 ? 1 : width, "0"));
+}
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