#ifndef PKTLINE_H #define PKTLINE_H #include "strbuf.h" /* * Write a packetized stream, where each line is preceded by * its length (including the header) as a 4-byte hex number. * A length of 'zero' means end of stream (and a length of 1-3 * would be an error). * * This is all pretty stupid, but we use this packetized line * format to make a streaming format possible without ever * over-running the read buffers. That way we'll never read * into what might be the pack data (which should go to another * process entirely). * * The writing side could use stdio, but since the reading * side can't, we stay with pure read/write interfaces. */ void packet_flush(int fd); void packet_delim(int fd); void packet_response_end(int fd); void packet_write_fmt(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3))); void packet_buf_flush(struct strbuf *buf); void packet_buf_delim(struct strbuf *buf); void set_packet_header(char *buf, int size); void packet_write(int fd_out, const char *buf, size_t size); void packet_buf_write(struct strbuf *buf, const char *fmt, ...) __attribute__((format (printf, 2, 3))); int packet_flush_gently(int fd); int packet_write_fmt_gently(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3))); int write_packetized_from_fd_no_flush(int fd_in, int fd_out); int write_packetized_from_buf_no_flush_count(const char *src_in, size_t len, int fd_out, int *packet_counter); static inline int write_packetized_from_buf_no_flush(const char *src_in, size_t len, int fd_out) { … } /* * Stdio versions of packet_write functions. When mixing these with fd * based functions, take care to call fflush(3) before doing fd writes or * closing the fd. */ void packet_fwrite(FILE *f, const char *buf, size_t size); void packet_fwrite_fmt(FILE *f, const char *fmt, ...) __attribute__((format (printf, 2, 3))); /* packet_fflush writes a flush packet and flushes the stdio buffer of f */ void packet_fflush(FILE *f); /* * Read a packetized line into the buffer, which must be at least size bytes * long. The return value specifies the number of bytes read into the buffer. * * If options does not contain PACKET_READ_GENTLE_ON_EOF, we will die under any * of the following conditions: * * 1. Read error from descriptor. * * 2. Protocol error from the remote (e.g., bogus length characters). * * 3. Receiving a packet larger than "size" bytes. * * 4. Truncated output from the remote (e.g., we expected a packet but got * EOF, or we got a partial packet followed by EOF). * * If options does contain PACKET_READ_GENTLE_ON_EOF, we will not die on * condition 4 (truncated input), but instead return -1. However, we will still * die for the other 3 conditions. * * If options contains PACKET_READ_CHOMP_NEWLINE, a trailing newline (if * present) is removed from the buffer before returning. * * If options contains PACKET_READ_DIE_ON_ERR_PACKET, it dies when it sees an * ERR packet. * * If options contains PACKET_READ_GENTLE_ON_READ_ERROR, we will not die * on read errors, but instead return -1. However, we may still die on an * ERR packet (if requested). */ #define PACKET_READ_GENTLE_ON_EOF … #define PACKET_READ_CHOMP_NEWLINE … #define PACKET_READ_DIE_ON_ERR_PACKET … #define PACKET_READ_GENTLE_ON_READ_ERROR … #define PACKET_READ_REDACT_URI_PATH … #define PACKET_READ_USE_SIDEBAND … int packet_read(int fd, char *buffer, unsigned size, int options); /* * Convert a four hex digit packet line length header into its numeric * representation. * * If lenbuf_hex contains non-hex characters, return -1. Otherwise, return the * numeric value of the length header. */ int packet_length(const char lenbuf_hex[4], size_t size); /* * Read a packetized line into a buffer like the 'packet_read()' function but * returns an 'enum packet_read_status' which indicates the status of the read. * The number of bytes read will be assigned to *pktlen if the status of the * read was 'PACKET_READ_NORMAL'. * * If src_buffer and *src_buffer are not NULL, it should point to a buffer * containing the packet data to parse, of at least *src_len bytes. After the * function returns, src_buf will be incremented and src_len decremented by the * number of bytes consumed. * * If src_buffer (or *src_buffer) is NULL, then data is read from the * descriptor "fd". */ enum packet_read_status { … }; enum packet_read_status packet_read_with_status(int fd, char **src_buffer, size_t *src_len, char *buffer, unsigned size, int *pktlen, int options); /* * Convenience wrapper for packet_read that is not gentle, and sets the * CHOMP_NEWLINE option. The return value is NULL for a flush packet, * and otherwise points to a static buffer (that may be overwritten by * subsequent calls). If the size parameter is not NULL, the length of the * packet is written to it. */ char *packet_read_line(int fd, int *size); /* * Convenience wrapper for packet_read that sets the PACKET_READ_GENTLE_ON_EOF * and CHOMP_NEWLINE options. The return value specifies the number of bytes * read into the buffer or -1 on truncated input. If the *dst_line parameter * is not NULL it will return NULL for a flush packet or when the number of * bytes copied is zero and otherwise points to a static buffer (that may be * overwritten by subsequent calls). If the size parameter is not NULL, the * length of the packet is written to it. */ int packet_read_line_gently(int fd, int *size, char **dst_line); /* * Reads a stream of variable sized packets until a flush packet is detected. */ ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out, int options); /* * Receive multiplexed output stream over git native protocol. * in_stream is the input stream from the remote, which carries data * in pkt_line format with band designator. Demultiplex it into out * and err and return error appropriately. Band #1 carries the * primary payload. Things coming over band #2 is not necessarily * error; they are usually informative message on the standard error * stream, aka "verbose"). A message over band #3 is a signal that * the remote died unexpectedly. A flush() concludes the stream. * * Returns SIDEBAND_FLUSH upon a normal conclusion, and SIDEBAND_PROTOCOL_ERROR * or SIDEBAND_REMOTE_ERROR if an error occurred. */ int recv_sideband(const char *me, int in_stream, int out); struct packet_reader { … }; /* * Initialize a 'struct packet_reader' object which is an * abstraction around the 'packet_read_with_status()' function. */ void packet_reader_init(struct packet_reader *reader, int fd, char *src_buffer, size_t src_len, int options); /* * Perform a packet read and return the status of the read. * The values of 'pktlen' and 'line' are updated based on the status of the * read as follows: * * PACKET_READ_ERROR: 'pktlen' is set to '-1' and 'line' is set to NULL * PACKET_READ_NORMAL: 'pktlen' is set to the number of bytes read * 'line' is set to point at the read line * PACKET_READ_FLUSH: 'pktlen' is set to '0' and 'line' is set to NULL */ enum packet_read_status packet_reader_read(struct packet_reader *reader); /* * Peek the next packet line without consuming it and return the status. * The next call to 'packet_reader_read()' will perform a read of the same line * that was peeked, consuming the line. * * Peeking multiple times without calling 'packet_reader_read()' will return * the same result. */ enum packet_read_status packet_reader_peek(struct packet_reader *reader); #define DEFAULT_PACKET_MAX … #define LARGE_PACKET_MAX … #define LARGE_PACKET_DATA_MAX … extern char packet_buffer[LARGE_PACKET_MAX]; struct packet_writer { … }; void packet_writer_init(struct packet_writer *writer, int dest_fd); /* These functions die upon failure. */ __attribute__((format (printf, 2, 3))) void packet_writer_write(struct packet_writer *writer, const char *fmt, ...); __attribute__((format (printf, 2, 3))) void packet_writer_error(struct packet_writer *writer, const char *fmt, ...); void packet_writer_delim(struct packet_writer *writer); void packet_writer_flush(struct packet_writer *writer); void packet_trace_identity(const char *prog); #endif
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