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curl/lib/mime.h
Patrick Monnerat 1e4cb333ef
mime: do not perform more than one read in a row
Input buffer filling may delay the data sending if data reads are slow.
To overcome this problem, file and callback data reads do not accumulate
in buffer anymore. All other data (memory data and mime framing) are
considered as fast and still concatenated in buffer.
As this may highly impact performance in terms of data overhead, an early
end of part data check is added to spare a read call.
When encoding a part's data, an encoder may require more bytes than made
available by a single read. In this case, the above rule does not apply
and reads are performed until the encoder is able to deliver some data.

Tests 643, 644, 645, 650 and 654 have been adapted to the output data
changes, with test data size reduced to avoid the boredom of long lists of
1-byte chunks in verification data.
New test 667 checks mimepost using single-byte read callback with encoder.
New test 668 checks the end of part data early detection.

Fixes #4826
Reported-by: MrdUkk on github
2020-03-07 23:26:00 +01:00

169 lines
7.0 KiB
C

#ifndef HEADER_CURL_MIME_H
#define HEADER_CURL_MIME_H
/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.haxx.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
***************************************************************************/
#include "curl_setup.h"
#define MIME_RAND_BOUNDARY_CHARS 16 /* Nb. of random boundary chars. */
#define MAX_ENCODED_LINE_LENGTH 76 /* Maximum encoded line length. */
#define ENCODING_BUFFER_SIZE 256 /* Encoding temp buffers size. */
/* Part flags. */
#define MIME_USERHEADERS_OWNER (1 << 0)
#define MIME_BODY_ONLY (1 << 1)
#define MIME_FAST_READ (1 << 2)
#define FILE_CONTENTTYPE_DEFAULT "application/octet-stream"
#define MULTIPART_CONTENTTYPE_DEFAULT "multipart/mixed"
#define DISPOSITION_DEFAULT "attachment"
/* Part source kinds. */
enum mimekind {
MIMEKIND_NONE = 0, /* Part not set. */
MIMEKIND_DATA, /* Allocated mime data. */
MIMEKIND_FILE, /* Data from file. */
MIMEKIND_CALLBACK, /* Data from `read' callback. */
MIMEKIND_MULTIPART, /* Data is a mime subpart. */
MIMEKIND_LAST
};
/* Readback state tokens. */
enum mimestate {
MIMESTATE_BEGIN, /* Readback has not yet started. */
MIMESTATE_CURLHEADERS, /* In curl-generated headers. */
MIMESTATE_USERHEADERS, /* In caller's supplied headers. */
MIMESTATE_EOH, /* End of headers. */
MIMESTATE_BODY, /* Placeholder. */
MIMESTATE_BOUNDARY1, /* In boundary prefix. */
MIMESTATE_BOUNDARY2, /* In boundary. */
MIMESTATE_CONTENT, /* In content. */
MIMESTATE_END, /* End of part reached. */
MIMESTATE_LAST
};
/* Mime headers strategies. */
enum mimestrategy {
MIMESTRATEGY_MAIL, /* Mime mail. */
MIMESTRATEGY_FORM, /* HTTP post form. */
MIMESTRATEGY_LAST
};
/* Content transfer encoder. */
typedef struct {
const char * name; /* Encoding name. */
size_t (*encodefunc)(char *buffer, size_t size, bool ateof,
curl_mimepart *part); /* Encoded read. */
curl_off_t (*sizefunc)(curl_mimepart *part); /* Encoded size. */
} mime_encoder;
/* Content transfer encoder state. */
typedef struct {
size_t pos; /* Position on output line. */
size_t bufbeg; /* Next data index in input buffer. */
size_t bufend; /* First unused byte index in input buffer. */
char buf[ENCODING_BUFFER_SIZE]; /* Input buffer. */
} mime_encoder_state;
/* Mime readback state. */
typedef struct {
enum mimestate state; /* Current state token. */
void *ptr; /* State-dependent pointer. */
curl_off_t offset; /* State-dependent offset. */
} mime_state;
/* minimum buffer size for the boundary string */
#define MIME_BOUNDARY_LEN (24 + MIME_RAND_BOUNDARY_CHARS + 1)
/* A mime multipart. */
struct curl_mime_s {
struct Curl_easy *easy; /* The associated easy handle. */
curl_mimepart *parent; /* Parent part. */
curl_mimepart *firstpart; /* First part. */
curl_mimepart *lastpart; /* Last part. */
char boundary[MIME_BOUNDARY_LEN]; /* The part boundary. */
mime_state state; /* Current readback state. */
};
/* A mime part. */
struct curl_mimepart_s {
struct Curl_easy *easy; /* The associated easy handle. */
curl_mime *parent; /* Parent mime structure. */
curl_mimepart *nextpart; /* Forward linked list. */
enum mimekind kind; /* The part kind. */
char *data; /* Memory data or file name. */
curl_read_callback readfunc; /* Read function. */
curl_seek_callback seekfunc; /* Seek function. */
curl_free_callback freefunc; /* Argument free function. */
void *arg; /* Argument to callback functions. */
FILE *fp; /* File pointer. */
struct curl_slist *curlheaders; /* Part headers. */
struct curl_slist *userheaders; /* Part headers. */
char *mimetype; /* Part mime type. */
char *filename; /* Remote file name. */
char *name; /* Data name. */
curl_off_t datasize; /* Expected data size. */
unsigned int flags; /* Flags. */
mime_state state; /* Current readback state. */
const mime_encoder *encoder; /* Content data encoder. */
mime_encoder_state encstate; /* Data encoder state. */
size_t lastreadstatus; /* Last read callback returned status. */
};
CURLcode Curl_mime_add_header(struct curl_slist **slp, const char *fmt, ...);
#if (!defined(CURL_DISABLE_HTTP) && !defined(CURL_DISABLE_MIME)) || \
!defined(CURL_DISABLE_SMTP) || !defined(CURL_DISABLE_IMAP)
/* Prototypes. */
void Curl_mime_initpart(curl_mimepart *part, struct Curl_easy *easy);
void Curl_mime_cleanpart(curl_mimepart *part);
CURLcode Curl_mime_duppart(curl_mimepart *dst, const curl_mimepart *src);
CURLcode Curl_mime_set_subparts(curl_mimepart *part,
curl_mime *subparts, int take_ownership);
CURLcode Curl_mime_prepare_headers(curl_mimepart *part,
const char *contenttype,
const char *disposition,
enum mimestrategy strategy);
curl_off_t Curl_mime_size(curl_mimepart *part);
size_t Curl_mime_read(char *buffer, size_t size, size_t nitems,
void *instream);
CURLcode Curl_mime_rewind(curl_mimepart *part);
const char *Curl_mime_contenttype(const char *filename);
void Curl_mime_unpause(curl_mimepart *part);
#else
/* if disabled */
#define Curl_mime_initpart(x,y)
#define Curl_mime_cleanpart(x)
#define Curl_mime_duppart(x,y) CURLE_OK /* Nothing to duplicate. Succeed */
#define Curl_mime_set_subparts(a,b,c) CURLE_NOT_BUILT_IN
#define Curl_mime_prepare_headers(a,b,c,d) CURLE_NOT_BUILT_IN
#define Curl_mime_size(x) (curl_off_t) -1
#define Curl_mime_read NULL
#define Curl_mime_rewind(x) ((void)x, CURLE_NOT_BUILT_IN)
#define Curl_mime_unpause(x)
#endif
#endif /* HEADER_CURL_MIME_H */