diff options
Diffstat (limited to 'libmailutils/filter/fromflt.c')
| -rw-r--r-- | libmailutils/filter/fromflt.c | 283 |
1 files changed, 283 insertions, 0 deletions
diff --git a/libmailutils/filter/fromflt.c b/libmailutils/filter/fromflt.c new file mode 100644 index 000000000..d96d46d85 --- /dev/null +++ b/libmailutils/filter/fromflt.c @@ -0,0 +1,283 @@ +/* GNU Mailutils -- a suite of utilities for electronic mail + Copyright (C) 2003, 2007, 2010 Free Software Foundation, Inc. + + This library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 3 of the License, or (at your option) any later version. + + This library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General + Public License along with this library; if not, write to the + Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, + Boston, MA 02110-1301 USA */ + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +#include <stdlib.h> +#include <string.h> +#include <mailutils/errno.h> +#include <mailutils/filter.h> +#include <mailutils/stream.h> + +enum from_decode_state + { + from_decode_init, + from_decode_nl, + from_decode_char + }; + +#define GT_FROM_MARK_STR ">From " +#define GT_FROM_MARK_LEN (sizeof (GT_FROM_MARK_STR) - 1) + +/* Move min(isize,osize) bytes from iptr to optr, replacing each '>From ' + at the beginning of line with 'From '. */ +static enum mu_filter_result +_from_decoder (void *xd, + enum mu_filter_command cmd, + struct mu_filter_io *iobuf) +{ + int *pstate = xd; + const unsigned char *iptr; + size_t isize; + char *optr; + size_t osize; + enum from_decode_state state; + size_t i, j; + + switch (cmd) + { + case mu_filter_init: + *pstate = from_decode_init; + return mu_filter_ok; + + case mu_filter_done: + return mu_filter_ok; + + default: + state = *pstate; + break; + } + + iptr = (const unsigned char *) iobuf->input; + isize = iobuf->isize; + optr = iobuf->output; + osize = iobuf->osize; + + for (i = j = 0; i < isize && j < osize; i++) + { + unsigned char c = *iptr++; + + if (c == '\n') + state = from_decode_nl; + else if (state == from_decode_init || state == from_decode_nl) + { + size_t len = isize - i; + + if (len < GT_FROM_MARK_LEN) + { + if (memcmp (iptr - 1, GT_FROM_MARK_STR, len) == 0) + { + if (i == 0) + { + iobuf->isize = GT_FROM_MARK_LEN - len; + return mu_filter_moreinput; + } + break; + } + else + state = from_decode_char; + } + else if (memcmp (iptr - 1, GT_FROM_MARK_STR, GT_FROM_MARK_LEN) == 0) + { + /* Skip > */ + state = from_decode_char; + continue; + } + } + optr[j++] = c; + } + + *pstate = state; + iobuf->isize = i; + iobuf->osize = j; + return mu_filter_ok; +} + +#define FROM_MARK_STR "From " +#define FROM_MARK_LEN (sizeof (FROM_MARK_STR) - 1) + +enum from_encode_state + { + from_encode_init, + from_encode_nl, + from_encode_char, + from_encode_gt, + from_encode_f, + from_encode_r, + from_encode_o, + from_encode_m, + from_encode_sp + }; + +static int length_to_state_tab[] = { + from_encode_gt, + from_encode_f, + from_encode_r, + from_encode_o, + from_encode_m, + from_encode_sp +}; + +static int state_to_length_tab[] = { + 0, 0, 0, + GT_FROM_MARK_LEN, + GT_FROM_MARK_LEN-1, + GT_FROM_MARK_LEN-2, + GT_FROM_MARK_LEN-3, + GT_FROM_MARK_LEN-4, + GT_FROM_MARK_LEN-5 +}; + +/* Move min(isize,osize) bytes from iptr to optr, replacing each 'From ' + at the beginning of line with '>From '. */ + +static enum mu_filter_result +_from_encoder (void *xd, + enum mu_filter_command cmd, + struct mu_filter_io *iobuf) +{ + int *pstate = xd; + const unsigned char *iptr; + size_t isize; + char *optr; + size_t osize; + enum from_encode_state state; + size_t i, j; + + switch (cmd) + { + case mu_filter_init: + *pstate = from_encode_init; + return mu_filter_ok; + + case mu_filter_done: + return mu_filter_ok; + + default: + state = *pstate; + switch (state) + { + case from_encode_init: + case from_encode_nl: + case from_encode_char: + break; + + default: + osize = state_to_length_tab[state]; + if (iobuf->osize < osize) + { + iobuf->osize = osize; + return mu_filter_moreoutput; + } + memcpy (iobuf->output, GT_FROM_MARK_STR + GT_FROM_MARK_LEN - osize, + osize); + iobuf->osize = osize; + iobuf->isize = osize; + *pstate = from_encode_init; + return mu_filter_ok; + } + break; + } + + iptr = (const unsigned char *) iobuf->input; + isize = iobuf->isize; + optr = iobuf->output; + osize = iobuf->osize; + + for (i = j = 0; i < isize && j < osize; i++) + { + unsigned char c = *iptr++; + + if (c == '\n') + state = from_encode_nl; + else if (state == from_encode_init || state == from_encode_nl) + { + size_t len = isize - i; + + if (len < FROM_MARK_LEN) + { + if (memcmp (iptr - 1, FROM_MARK_STR, len) == 0) + { + if (i == 0) + { + iobuf->isize = FROM_MARK_LEN; + return mu_filter_moreinput; + } + break; + } + else + state = from_encode_char; + } + else if (memcmp (iptr - 1, FROM_MARK_STR, FROM_MARK_LEN) == 0) + { + size_t rest = osize - j; + + if (rest > GT_FROM_MARK_LEN) + rest = GT_FROM_MARK_LEN; + else if (rest < 2) + { + if (i == 0) + { + iobuf->osize = GT_FROM_MARK_LEN; + return mu_filter_moreoutput; + } + break; + } + + memcpy (optr + j, GT_FROM_MARK_STR, rest); + i += rest - 2; + iptr += rest - 2; + j += rest; + if (rest < GT_FROM_MARK_LEN) + state = length_to_state_tab[rest]; + else + state = from_encode_char; + continue; + } + else + state = from_encode_char; + } + optr[j++] = c; + } + *pstate = state; + iobuf->isize = i; + iobuf->osize = j; + return mu_filter_ok; +} + +static int +_from_alloc_state (void **pret, int mode, void *data MU_ARG_UNUSED) +{ + *pret = malloc (sizeof (int)); + if (!*pret) + return ENOMEM; + return 0; +} + +static struct _mu_filter_record _from_filter = { + "FROM", + 0, + _from_alloc_state, + _from_encoder, + _from_decoder +}; + +mu_filter_record_t mu_from_filter = &_from_filter; + |