/*

* Another stupid program, this one parsing the headers of an

* email to figure out authorship and subject

*/

#include "cache.h"

#include "builtin.h"

#include "utf8.h"

static FILE *cmitmsg, *patchfile, *fin, *fout;

static int keep_subject;

static const char *metainfo_charset;

static char line[1000];

static char name[1000];

static char email[1000];

static enum {

TE_DONTCARE, TE_QP, TE_BASE64,

} transfer_encoding;

static enum {

TYPE_TEXT, TYPE_OTHER,

} message_type;

static char charset[256];

static int patch_lines;

static char **p_hdr_data, **s_hdr_data;

#define MAX_HDR_PARSED 10

#define MAX_BOUNDARIES 5

static char *sanity_check(char *name, char *email)

{

int len = strlen(name);

if (len < 3 || len > 60)

return email;

if (strchr(name, '@') || strchr(name, '<') || strchr(name, '>'))

return email;

return name;

}

static int bogus_from(char *line)

{

/* John Doe <johndoe> */

char *bra, *ket, *dst, *cp;

/* This is fallback, so do not bother if we already have an

* e-mail address.

*/

if (*email)

return 0;

bra = strchr(line, '<');

if (!bra)

return 0;

ket = strchr(bra, '>');

if (!ket)

return 0;

for (dst = email, cp = bra+1; cp < ket; )

*dst++ = *cp++;

*dst = 0;

for (cp = line; isspace(*cp); cp++)

;

for (bra--; isspace(*bra); bra--)

*bra = 0;

cp = sanity_check(cp, email);

strcpy(name, cp);

return 1;

}

static int handle_from(char *in_line)

{

char line[1000];

char *at;

char *dst;

strcpy(line, in_line);

at = strchr(line, '@');

if (!at)

return bogus_from(line);

/*

* If we already have one email, don't take any confusing lines

*/

if (*email && strchr(at+1, '@'))

return 0;

/* Pick up the string around '@', possibly delimited with <>

* pair; that is the email part. White them out while copying.

*/

while (at > line) {

char c = at[-1];

if (isspace(c))

break;

if (c == '<') {

at[-1] = ' ';

break;

}

at--;

}

dst = email;

for (;;) {

unsigned char c = *at;

if (!c || c == '>' || isspace(c)) {

if (c == '>')

*at = ' ';

break;

}

*at++ = ' ';

*dst++ = c;

}

*dst++ = 0;

/* The remainder is name. It could be "John Doe <john.doe@xz>"

* or "john.doe@xz (John Doe)", but we have whited out the

* email part, so trim from both ends, possibly removing

* the () pair at the end.

*/

at = line + strlen(line);

while (at > line) {

unsigned char c = *--at;

if (!isspace(c)) {

at[(c == ')') ? 0 : 1] = 0;

break;

}

}

at = line;

for (;;) {

unsigned char c = *at;

if (!c || !isspace(c)) {

if (c == '(')

at++;

break;

}

at++;

}

at = sanity_check(at, email);

strcpy(name, at);

return 1;

}

static int handle_header(char *line, char *data, int ofs)

{

if (!line || !data)

return 1;

strcpy(data, line+ofs);

return 0;

}

/* NOTE NOTE NOTE. We do not claim we do full MIME. We just attempt

* to have enough heuristics to grok MIME encoded patches often found

* on our mailing lists. For example, we do not even treat header lines

* case insensitively.

*/

static int slurp_attr(const char *line, const char *name, char *attr)

{

const char *ends, *ap = strcasestr(line, name);

size_t sz;

if (!ap) {

*attr = 0;

return 0;

}

ap += strlen(name);

if (*ap == '"') {

ap++;

ends = "\"";

}

else

ends = "; \t";

sz = strcspn(ap, ends);

memcpy(attr, ap, sz);

attr[sz] = 0;

return 1;

}

struct content_type {

char *boundary;

int boundary_len;

};

static struct content_type content[MAX_BOUNDARIES];

static struct content_type *content_top = content;

static int handle_content_type(char *line)

{

char boundary[256];

if (strcasestr(line, "text/") == NULL)

message_type = TYPE_OTHER;

if (slurp_attr(line, "boundary=", boundary + 2)) {

memcpy(boundary, "--", 2);

if (content_top++ >= &content[MAX_BOUNDARIES]) {

fprintf(stderr, "Too many boundaries to handle\n");

exit(1);

}

content_top->boundary_len = strlen(boundary);

content_top->boundary = xmalloc(content_top->boundary_len+1);

strcpy(content_top->boundary, boundary);

}

if (slurp_attr(line, "charset=", charset)) {

int i, c;

for (i = 0; (c = charset[i]) != 0; i++)

charset[i] = tolower(c);

}

return 0;

}

static int handle_content_transfer_encoding(char *line)

{

if (strcasestr(line, "base64"))

transfer_encoding = TE_BASE64;

else if (strcasestr(line, "quoted-printable"))

transfer_encoding = TE_QP;

else

transfer_encoding = TE_DONTCARE;

return 0;

}

static int is_multipart_boundary(const char *line)

{

return (!memcmp(line, content_top->boundary, content_top->boundary_len));

}

static int eatspace(char *line)

{

int len = strlen(line);

while (len > 0 && isspace(line[len-1]))

line[--len] = 0;

return len;

}

static char *cleanup_subject(char *subject)

{

for (;;) {

char *p;

int len, remove;

switch (*subject) {

case 'r': case 'R':

if (!memcmp("e:", subject+1, 2)) {

subject += 3;

continue;

}

break;

case ' ': case '\t': case ':':

subject++;

continue;

case '[':

p = strchr(subject, ']');

if (!p) {

subject++;

continue;

}

len = strlen(p);

remove = p - subject;

if (remove <= len *2) {

subject = p+1;

continue;

}

break;

}

eatspace(subject);

return subject;

}

}

static void cleanup_space(char *buf)

{

unsigned char c;

while ((c = *buf) != 0) {

buf++;

if (isspace(c)) {

buf[-1] = ' ';

c = *buf;

while (isspace(c)) {

int len = strlen(buf);

memmove(buf, buf+1, len);

c = *buf;

}

}

}

}

static void decode_header(char *it, unsigned itsize);

static const char *header[MAX_HDR_PARSED] = {

"From","Subject","Date",

};

static int check_header(char *line, unsigned linesize, char **hdr_data, int overwrite)

{

int i;

/* search for the interesting parts */

for (i = 0; header[i]; i++) {

int len = strlen(header[i]);

if ((!hdr_data[i] || overwrite) &&

!strncasecmp(line, header[i], len) &&

line[len] == ':' && isspace(line[len + 1])) {

/* Unwrap inline B and Q encoding, and optionally

* normalize the meta information to utf8.

*/

decode_header(line + len + 2, linesize - len - 2);

hdr_data[i] = xmalloc(1000 * sizeof(char));

if (! handle_header(line, hdr_data[i], len + 2)) {

return 1;

}

}

}

/* Content stuff */

if (!strncasecmp(line, "Content-Type", 12) &&

line[12] == ':' && isspace(line[12 + 1])) {

decode_header(line + 12 + 2, linesize - 12 - 2);

if (! handle_content_type(line)) {

return 1;

}

}

if (!strncasecmp(line, "Content-Transfer-Encoding", 25) &&

line[25] == ':' && isspace(line[25 + 1])) {

decode_header(line + 25 + 2, linesize - 25 - 2);

if (! handle_content_transfer_encoding(line)) {

return 1;

}

}

/* for inbody stuff */

if (!memcmp(">From", line, 5) && isspace(line[5]))

return 1;

if (!memcmp("[PATCH]", line, 7) && isspace(line[7])) {

for (i = 0; header[i]; i++) {

if (!memcmp("Subject: ", header[i], 9)) {

if (! handle_header(line, hdr_data[i], 0)) {

return 1;

}

}

}

}

/* no match */

return 0;

}

static int is_rfc2822_header(char *line)

{

/*

* The section that defines the loosest possible

* field name is "3.6.8 Optional fields".

*

* optional-field = field-name ":" unstructured CRLF

* field-name = 1*ftext

* ftext = %d33-57 / %59-126

*/

int ch;

char *cp = line;

/* Count mbox From headers as headers */

if (!memcmp(line, "From ", 5) || !memcmp(line, ">From ", 6))

return 1;

while ((ch = *cp++)) {

if (ch == ':')

return cp != line;

if ((33 <= ch && ch <= 57) ||

(59 <= ch && ch <= 126))

continue;

break;

}

return 0;

}

/*

* sz is size of 'line' buffer in bytes. Must be reasonably

* long enough to hold one physical real-world e-mail line.

*/

static int read_one_header_line(char *line, int sz, FILE *in)

{

int len;

/*

* We will read at most (sz-1) bytes and then potentially

* re-add NUL after it. Accessing line[sz] after this is safe

* and we can allow len to grow up to and including sz.

*/

sz--;

/* Get the first part of the line. */

if (!fgets(line, sz, in))

return 0;

/*

* Is it an empty line or not a valid rfc2822 header?

* If so, stop here, and return false ("not a header")

*/

len = eatspace(line);

if (!len || !is_rfc2822_header(line)) {

/* Re-add the newline */

line[len] = '\n';

line[len + 1] = '\0';

return 0;

}

/*

* Now we need to eat all the continuation lines..

* Yuck, 2822 header "folding"

*/

for (;;) {

int peek, addlen;

static char continuation[1000];

peek = fgetc(in); ungetc(peek, in);

if (peek != ' ' && peek != '\t')

break;

if (!fgets(continuation, sizeof(continuation), in))

break;

addlen = eatspace(continuation);

if (len < sz - 1) {

if (addlen >= sz - len)

addlen = sz - len - 1;

memcpy(line + len, continuation, addlen);

line[len] = '\n';

len += addlen;

}

}

line[len] = 0;

return 1;

}

static int decode_q_segment(char *in, char *ot, unsigned otsize, char *ep, int rfc2047)

{

char *otend = ot + otsize;

int c;

while ((c = *in++) != 0 && (in <= ep)) {

if (ot == otend) {

*--ot = '\0';

return -1;

}

if (c == '=') {

int d = *in++;

if (d == '\n' || !d)

break; /* drop trailing newline */

*ot++ = ((hexval(d) << 4) | hexval(*in++));

continue;

}

if (rfc2047 && c == '_') /* rfc2047 4.2 (2) */

c = 0x20;

*ot++ = c;

}

*ot = 0;

return 0;

}

static int decode_b_segment(char *in, char *ot, unsigned otsize, char *ep)

{

/* Decode in..ep, possibly in-place to ot */

int c, pos = 0, acc = 0;

char *otend = ot + otsize;

while ((c = *in++) != 0 && (in <= ep)) {

if (ot == otend) {

*--ot = '\0';

return -1;

}

if (c == '+')

c = 62;

else if (c == '/')

c = 63;

else if ('A' <= c && c <= 'Z')

c -= 'A';

else if ('a' <= c && c <= 'z')

c -= 'a' - 26;

else if ('0' <= c && c <= '9')

c -= '0' - 52;

else if (c == '=') {

/* padding is almost like (c == 0), except we do

* not output NUL resulting only from it;

* for now we just trust the data.

*/

c = 0;

}

else

continue; /* garbage */

switch (pos++) {

case 0:

acc = (c << 2);

break;

case 1:

*ot++ = (acc | (c >> 4));

acc = (c & 15) << 4;

break;

case 2:

*ot++ = (acc | (c >> 2));

acc = (c & 3) << 6;

break;

case 3:

*ot++ = (acc | c);

acc = pos = 0;

break;

}

}

*ot = 0;

return 0;

}

/*

* When there is no known charset, guess.

*

* Right now we assume that if the target is UTF-8 (the default),

* and it already looks like UTF-8 (which includes US-ASCII as its

* subset, of course) then that is what it is and there is nothing

* to do.

*

* Otherwise, we default to assuming it is Latin1 for historical

* reasons.

*/

static const char *guess_charset(const char *line, const char *target_charset)

{

if (is_encoding_utf8(target_charset)) {

if (is_utf8(line))

return NULL;

}

return "latin1";

}

static void convert_to_utf8(char *line, unsigned linesize, const char *charset)

{

char *out;

if (!charset || !*charset) {

charset = guess_charset(line, metainfo_charset);

if (!charset)

return;

}

if (!strcmp(metainfo_charset, charset))

return;

out = reencode_string(line, metainfo_charset, charset);

if (!out)

die("cannot convert from %s to %s\n",

charset, metainfo_charset);

strlcpy(line, out, linesize);

free(out);

}

static int decode_header_bq(char *it, unsigned itsize)

{

char *in, *out, *ep, *cp, *sp;

char outbuf[1000];

int rfc2047 = 0;

in = it;

out = outbuf;

while ((ep = strstr(in, "=?")) != NULL) {

int sz, encoding;

char charset_q[256], piecebuf[256];

rfc2047 = 1;

if (in != ep) {

sz = ep - in;

memcpy(out, in, sz);

out += sz;

in += sz;

}

/* E.g.

* ep : "=?iso-2022-jp?B?GyR...?= foo"

* ep : "=?ISO-8859-1?Q?Foo=FCbar?= baz"

*/

ep += 2;

cp = strchr(ep, '?');

if (!cp)

return rfc2047; /* no munging */

for (sp = ep; sp < cp; sp++)

charset_q[sp - ep] = tolower(*sp);

charset_q[cp - ep] = 0;

encoding = cp[1];

if (!encoding || cp[2] != '?')

return rfc2047; /* no munging */

ep = strstr(cp + 3, "?=");

if (!ep)

return rfc2047; /* no munging */

switch (tolower(encoding)) {

default:

return rfc2047; /* no munging */

case 'b':

sz = decode_b_segment(cp + 3, piecebuf, sizeof(piecebuf), ep);

break;

case 'q':

sz = decode_q_segment(cp + 3, piecebuf, sizeof(piecebuf), ep, 1);

break;

}

if (sz < 0)

return rfc2047;

if (metainfo_charset)

convert_to_utf8(piecebuf, sizeof(piecebuf), charset_q);

sz = strlen(piecebuf);

if (outbuf + sizeof(outbuf) <= out + sz)

return rfc2047; /* no munging */

strcpy(out, piecebuf);

out += sz;

in = ep + 2;

}

strcpy(out, in);

strlcpy(it, outbuf, itsize);

return rfc2047;

}

static void decode_header(char *it, unsigned itsize)

{

if (decode_header_bq(it, itsize))

return;

/* otherwise "it" is a straight copy of the input.

* This can be binary guck but there is no charset specified.

*/

if (metainfo_charset)

convert_to_utf8(it, itsize, "");

}

static void decode_transfer_encoding(char *line, unsigned linesize)

{

char *ep;

switch (transfer_encoding) {

case TE_QP:

ep = line + strlen(line);

decode_q_segment(line, line, linesize, ep, 0);

break;

case TE_BASE64:

ep = line + strlen(line);

decode_b_segment(line, line, linesize, ep);

break;

case TE_DONTCARE:

break;

}

}

static int handle_filter(char *line, unsigned linesize);

static int find_boundary(void)

{

while(fgets(line, sizeof(line), fin) != NULL) {

if (is_multipart_boundary(line))

return 1;

}

return 0;

}

static int handle_boundary(void)

{

char newline[]="\n";

again:

if (!memcmp(line+content_top->boundary_len, "--", 2)) {

/* we hit an end boundary */

/* pop the current boundary off the stack */

free(content_top->boundary);

/* technically won't happen as is_multipart_boundary()

will fail first. But just in case..

*/

if (content_top-- < content) {

fprintf(stderr, "Detected mismatched boundaries, "

"can't recover\n");

exit(1);

}

handle_filter(newline, sizeof(newline));

/* skip to the next boundary */

if (!find_boundary())

return 0;

goto again;

}

/* set some defaults */

transfer_encoding = TE_DONTCARE;

charset[0] = 0;

message_type = TYPE_TEXT;

/* slurp in this section's info */

while (read_one_header_line(line, sizeof(line), fin))

check_header(line, sizeof(line), p_hdr_data, 0);

/* eat the blank line after section info */

return (fgets(line, sizeof(line), fin) != NULL);

}

static inline int patchbreak(const char *line)

{

/* Beginning of a "diff -" header? */

if (!memcmp("diff -", line, 6))

return 1;

/* CVS "Index: " line? */

if (!memcmp("Index: ", line, 7))

return 1;

/*

* "--- <filename>" starts patches without headers

* "---<sp>*" is a manual separator

*/

if (!memcmp("---", line, 3)) {

line += 3;

/* space followed by a filename? */

if (line[0] == ' ' && !isspace(line[1]))

return 1;

/* Just whitespace? */

for (;;) {

unsigned char c = *line++;

if (c == '\n')

return 1;

if (!isspace(c))

break;

}

return 0;

}

return 0;

}

static int handle_commit_msg(char *line, unsigned linesize)

{

static int still_looking = 1;

char *endline = line + linesize;

if (!cmitmsg)

return 0;

if (still_looking) {

char *cp = line;

if (isspace(*line)) {

for (cp = line + 1; *cp; cp++) {

if (!isspace(*cp))

break;

}

if (!*cp)

return 0;

}

if ((still_looking = check_header(cp, endline - cp, s_hdr_data, 0)) != 0)

return 0;

}

/* normalize the log message to UTF-8. */

if (metainfo_charset)

convert_to_utf8(line, endline - line, charset);

if (patchbreak(line)) {

fclose(cmitmsg);

cmitmsg = NULL;

return 1;

}

fputs(line, cmitmsg);

return 0;

}

static int handle_patch(char *line)

{

fputs(line, patchfile);

patch_lines++;

return 0;

}

static int handle_filter(char *line, unsigned linesize)

{

static int filter = 0;

/* filter tells us which part we left off on

* a non-zero return indicates we hit a filter point

*/

switch (filter) {

case 0:

if (!handle_commit_msg(line, linesize))

break;

filter++;

case 1:

if (!handle_patch(line))

break;

filter++;

default:

return 1;

}

return 0;

}

static void handle_body(void)

{

int rc = 0;

static char newline[2000];

static char *np = newline;

/* Skip up to the first boundary */

if (content_top->boundary) {

if (!find_boundary())

return;

}

do {

/* process any boundary lines */

if (content_top->boundary && is_multipart_boundary(line)) {

/* flush any leftover */

if ((transfer_encoding == TE_BASE64) &&

(np != newline)) {

handle_filter(newline, sizeof(newline));

}

if (!handle_boundary())

return;

}

/* Unwrap transfer encoding */

decode_transfer_encoding(line, sizeof(line));

switch (transfer_encoding) {

case TE_BASE64:

case TE_QP:

{

char *op = line;

/* binary data most likely doesn't have newlines */

if (message_type != TYPE_TEXT) {

rc = handle_filter(line, sizeof(newline));

break;

}

/* this is a decoded line that may contain

* multiple new lines. Pass only one chunk

* at a time to handle_filter()

*/

do {

while (*op != '\n' && *op != 0)

*np++ = *op++;

*np = *op;

if (*np != 0) {

/* should be sitting on a new line */

*(++np) = 0;

op++;

rc = handle_filter(newline, sizeof(newline));

np = newline;

}

} while (*op != 0);

/* the partial chunk is saved in newline and

* will be appended by the next iteration of fgets

*/

break;

}

default:

rc = handle_filter(line, sizeof(newline));

}

if (rc)

/* nothing left to filter */

break;

} while (fgets(line, sizeof(line), fin));

return;

}

static void output_header_lines(FILE *fout, const char *hdr, char *data)

{

while (1) {

char *ep = strchr(data, '\n');

int len;

if (!ep)

len = strlen(data);

else

len = ep - data;

fprintf(fout, "%s: %.*s\n", hdr, len, data);

if (!ep)

break;

data = ep + 1;

}

}

static void handle_info(void)

{

char *sub;

char *hdr;

int i;

for (i = 0; header[i]; i++) {

/* only print inbody headers if we output a patch file */

if (patch_lines && s_hdr_data[i])

hdr = s_hdr_data[i];

else if (p_hdr_data[i])

hdr = p_hdr_data[i];

else

continue;

if (!memcmp(header[i], "Subject", 7)) {

if (keep_subject)

sub = hdr;

else {

sub = cleanup_subject(hdr);

cleanup_space(sub);

}

output_header_lines(fout, "Subject", sub);

} else if (!memcmp(header[i], "From", 4)) {

handle_from(hdr);

fprintf(fout, "Author: %s\n", name);

fprintf(fout, "Email: %s\n", email);

} else {

cleanup_space(hdr);

fprintf(fout, "%s: %s\n", header[i], hdr);

}

}

fprintf(fout, "\n");

}

static int mailinfo(FILE *in, FILE *out, int ks, const char *encoding,

const char *msg, const char *patch)

{

int peek;

keep_subject = ks;

metainfo_charset = encoding;

fin = in;

fout = out;

cmitmsg = fopen(msg, "w");

if (!cmitmsg) {

perror(msg);

return -1;

}

patchfile = fopen(patch, "w");

if (!patchfile) {

perror(patch);

fclose(cmitmsg);

return -1;

}

p_hdr_data = xcalloc(MAX_HDR_PARSED, sizeof(char *));

s_hdr_data = xcalloc(MAX_HDR_PARSED, sizeof(char *));

do {

peek = fgetc(in);

} while (isspace(peek));

ungetc(peek, in);

/* process the email header */

while (read_one_header_line(line, sizeof(line), fin))

check_header(line, sizeof(line), p_hdr_data, 1);

handle_body();

handle_info();

return 0;

}

static const char mailinfo_usage[] =

"git-mailinfo [-k] [-u | --encoding=<encoding>] msg patch <mail >info";

int cmd_mailinfo(int argc, const char **argv, const char *prefix)

{

const char *def_charset;

/* NEEDSWORK: might want to do the optional .git/ directory

* discovery

*/

git_config(git_default_config);

def_charset = (git_commit_encoding ? git_commit_encoding : "utf-8");

metainfo_charset = def_charset;

while (1 < argc && argv[1][0] == '-') {

if (!strcmp(argv[1], "-k"))

keep_subject = 1;

else if (!strcmp(argv[1], "-u"))

metainfo_charset = def_charset;

else if (!strcmp(argv[1], "-n"))

metainfo_charset = NULL;

else if (!prefixcmp(argv[1], "--encoding="))

metainfo_charset = argv[1] + 11;

else

usage(mailinfo_usage);

argc--; argv++;

}

if (argc != 3)

usage(mailinfo_usage);

return !!mailinfo(stdin, stdout, keep_subject, metainfo_charset, argv[1], argv[2]);

}