diff options
Diffstat (limited to 'usr.sbin/ctm/ctm_rmail/ctm_rmail.c')
| -rw-r--r-- | usr.sbin/ctm/ctm_rmail/ctm_rmail.c | 672 |
1 files changed, 672 insertions, 0 deletions
diff --git a/usr.sbin/ctm/ctm_rmail/ctm_rmail.c b/usr.sbin/ctm/ctm_rmail/ctm_rmail.c new file mode 100644 index 0000000..a46a58aa --- /dev/null +++ b/usr.sbin/ctm/ctm_rmail/ctm_rmail.c @@ -0,0 +1,672 @@ +/* + * Accept one (or more) ASCII encoded chunks that together make a compressed + * CTM delta. Decode them and reconstruct the deltas. Any completed + * deltas may be passed to ctm for unpacking. + * + * Author: Stephen McKay + * + * NOTICE: This is free software. I hope you get some use from this program. + * In return you should think about all the nice people who give away software. + * Maybe you should write some free software too. + * + * $FreeBSD$ + */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <ctype.h> +#include <errno.h> +#include <unistd.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <limits.h> +#include "error.h" +#include "options.h" + +#define CTM_STATUS ".ctm_status" + +char *piece_dir = NULL; /* Where to store pieces of deltas. */ +char *delta_dir = NULL; /* Where to store completed deltas. */ +char *base_dir = NULL; /* The tree to apply deltas to. */ +int delete_after = 0; /* Delete deltas after ctm applies them. */ +int apply_verbose = 0; /* Run with '-v' */ +int set_time = 0; /* Set the time of the files that is changed. */ +int mask = 0; /* The current umask */ + +void apply_complete(void); +int read_piece(char *input_file); +int combine_if_complete(char *delta, int pce, int npieces); +int combine(char *delta, int npieces, char *dname, char *pname, char *tname); +int decode_line(char *line, char *out_buf); +int lock_file(char *name); + +/* + * If given a '-p' flag, read encoded delta pieces from stdin or file + * arguments, decode them and assemble any completed deltas. If given + * a '-b' flag, pass any completed deltas to 'ctm' for application to + * the source tree. The '-d' flag is mandatory, but either of '-p' or + * '-b' can be omitted. If given the '-l' flag, notes and errors will + * be timestamped and written to the given file. + * + * Exit status is 0 for success or 1 for indigestible input. That is, + * 0 means the encode input pieces were decoded and stored, and 1 means + * some input was discarded. If a delta fails to apply, this won't be + * reflected in the exit status. In this case, the delta is left in + * 'deltadir'. + */ +int +main(int argc, char **argv) + { + char *log_file = NULL; + int status = 0; + int fork_ctm = 0; + + mask = umask(0); + umask(mask); + + err_prog_name(argv[0]); + + OPTIONS("[-Dfuv] [-p piecedir] [-d deltadir] [-b basedir] [-l log] [file ...]") + FLAG('D', delete_after) + FLAG('f', fork_ctm) + FLAG('u', set_time) + FLAG('v', apply_verbose) + STRING('p', piece_dir) + STRING('d', delta_dir) + STRING('b', base_dir) + STRING('l', log_file) + ENDOPTS + + if (delta_dir == NULL) + usage(); + + if (piece_dir == NULL && (base_dir == NULL || argc > 1)) + usage(); + + if (log_file != NULL) + err_set_log(log_file); + + /* + * Digest each file in turn, or just stdin if no files were given. + */ + if (argc <= 1) + { + if (piece_dir != NULL) + status = read_piece(NULL); + } + else + { + while (*++argv != NULL) + status |= read_piece(*argv); + } + + /* + * Maybe it's time to look for and apply completed deltas with ctm. + * + * Shall we report back to sendmail immediately, and let a child do + * the work? Sendmail will be waiting for us to complete, delaying + * other mail, and possibly some intermediate process (like MH slocal) + * will terminate us if we take too long! + * + * If fork() fails, it's unlikely we'll be able to run ctm, so give up. + * Also, the child exit status is unimportant. + */ + if (base_dir != NULL) + if (!fork_ctm || fork() == 0) + apply_complete(); + + return status; + } + + +/* + * Construct the file name of a piece of a delta. + */ +#define mk_piece_name(fn,d,p,n) \ + sprintf((fn), "%s/%s+%03d-%03d", piece_dir, (d), (p), (n)) + +/* + * Construct the file name of an assembled delta. + */ +#define mk_delta_name(fn,d) \ + sprintf((fn), "%s/%s", delta_dir, (d)) + +/* + * If the next required delta is now present, let ctm lunch on it and any + * contiguous deltas. + */ +void +apply_complete() + { + int i, dn; + int lfd; + FILE *fp, *ctm; + struct stat sb; + char class[20]; + char delta[30]; + char junk[2]; + char fname[PATH_MAX]; + char here[PATH_MAX]; + char buf[PATH_MAX*2]; + + /* + * Grab a lock on the ctm mutex file so that we can be sure we are + * working alone, not fighting another ctm_rmail! + */ + strcpy(fname, delta_dir); + strcat(fname, "/.mutex_apply"); + if ((lfd = lock_file(fname)) < 0) + return; + + /* + * Find out which delta ctm needs next. + */ + sprintf(fname, "%s/%s", base_dir, CTM_STATUS); + if ((fp = fopen(fname, "r")) == NULL) + { + close(lfd); + return; + } + + i = fscanf(fp, "%19s %d %c", class, &dn, junk); + fclose(fp); + if (i != 2) + { + close(lfd); + return; + } + + /* + * We might need to convert the delta filename to an absolute pathname. + */ + here[0] = '\0'; + if (delta_dir[0] != '/') + { + getcwd(here, sizeof(here)-1); + i = strlen(here) - 1; + if (i >= 0 && here[i] != '/') + { + here[++i] = '/'; + here[++i] = '\0'; + } + } + + /* + * Keep applying deltas until we run out or something bad happens. + */ + for (;;) + { + sprintf(delta, "%s.%04d.gz", class, ++dn); + mk_delta_name(fname, delta); + + if (stat(fname, &sb) < 0) + break; + + sprintf(buf, "(cd %s && ctm %s%s%s%s) 2>&1", base_dir, + set_time ? "-u " : "", + apply_verbose ? "-v " : "", here, fname); + if ((ctm = popen(buf, "r")) == NULL) + { + err("ctm failed to apply %s", delta); + break; + } + + while (fgets(buf, sizeof(buf), ctm) != NULL) + { + i = strlen(buf) - 1; + if (i >= 0 && buf[i] == '\n') + buf[i] = '\0'; + err("ctm: %s", buf); + } + + if (pclose(ctm) != 0) + { + err("ctm failed to apply %s", delta); + break; + } + + if (delete_after) + unlink(fname); + + err("%s applied%s", delta, delete_after ? " and deleted" : ""); + } + + /* + * Closing the lock file clears the lock. + */ + close(lfd); + } + + +/* + * This cheap plastic checksum effectively rotates our checksum-so-far + * left one, then adds the character. We only want 16 bits of it, and + * don't care what happens to the rest. It ain't much, but it's small. + */ +#define add_ck(sum,x) \ + ((sum) += ((x)&0xff) + (sum) + (((sum)&0x8000) ? 1 : 0)) + + +/* + * Decode the data between BEGIN and END, and stash it in the staging area. + * Multiple pieces can be present in a single file, bracketed by BEGIN/END. + * If we have all pieces of a delta, combine them. Returns 0 on success, + * and 1 for any sort of failure. + */ +int +read_piece(char *input_file) + { + int status = 0; + FILE *ifp, *ofp = 0; + int decoding = 0; + int got_one = 0; + int line_no = 0; + int i, n; + int pce, npieces; + unsigned claimed_cksum; + unsigned short cksum = 0; + char out_buf[200]; + char line[200]; + char delta[30]; + char pname[PATH_MAX]; + char tname[PATH_MAX]; + char junk[2]; + + ifp = stdin; + if (input_file != NULL && (ifp = fopen(input_file, "r")) == NULL) + { + err("cannot open '%s' for reading", input_file); + return 1; + } + + while (fgets(line, sizeof(line), ifp) != NULL) + { + line_no++; + + /* + * Remove all trailing white space. + */ + i = strlen(line) - 1; + while (i > 0 && isspace(line[i])) + line[i--] = '\0'; + + /* + * Look for the beginning of an encoded piece. + */ + if (!decoding) + { + char *s; + int fd = -1; + + if (sscanf(line, "CTM_MAIL BEGIN %29s %d %d %c", + delta, &pce, &npieces, junk) != 3) + continue; + + while ((s = strchr(delta, '/')) != NULL) + *s = '_'; + + got_one++; + strcpy(tname, piece_dir); + strcat(tname, "/p.XXXXXXXXXX"); + if ((fd = mkstemp(tname)) == -1 || + (ofp = fdopen(fd, "w")) == NULL) + { + if (fd != -1) { + err("cannot open '%s' for writing", tname); + close(fd); + } + else + err("*mkstemp: '%s'", tname); + status++; + continue; + } + + cksum = 0xffff; + decoding++; + continue; + } + + /* + * We are decoding. Stop if we see the end flag. + */ + if (sscanf(line, "CTM_MAIL END %d %c", &claimed_cksum, junk) == 1) + { + int e; + + decoding = 0; + + fflush(ofp); + e = ferror(ofp); + fclose(ofp); + + if (e) + err("error writing %s", tname); + + if (cksum != claimed_cksum) + err("checksum: read %d, calculated %d", claimed_cksum, cksum); + + if (e || cksum != claimed_cksum) + { + err("%s %d/%d discarded", delta, pce, npieces); + unlink(tname); + status++; + continue; + } + + mk_piece_name(pname, delta, pce, npieces); + if (rename(tname, pname) < 0) + { + err("*rename: '%s' to '%s'", tname, pname); + err("%s %d/%d lost!", delta, pce, npieces); + unlink(tname); + status++; + continue; + } + + err("%s %d/%d stored", delta, pce, npieces); + + if (!combine_if_complete(delta, pce, npieces)) + status++; + continue; + } + + /* + * Must be a line of encoded data. Decode it, sum it, and save it. + */ + n = decode_line(line, out_buf); + if (n <= 0) + { + err("line %d: illegal character: '%c'", line_no, line[-n]); + err("%s %d/%d discarded", delta, pce, npieces); + + fclose(ofp); + unlink(tname); + + status++; + decoding = 0; + continue; + } + + for (i = 0; i < n; i++) + add_ck(cksum, out_buf[i]); + + fwrite(out_buf, sizeof(char), n, ofp); + } + + if (decoding) + { + err("truncated file"); + err("%s %d/%d discarded", delta, pce, npieces); + + fclose(ofp); + unlink(tname); + + status++; + } + + if (ferror(ifp)) + { + err("error reading %s", input_file == NULL ? "stdin" : input_file); + status++; + } + + if (input_file != NULL) + fclose(ifp); + + if (!got_one) + { + err("message contains no delta"); + status++; + } + + return (status != 0); + } + + +/* + * Put the pieces together to form a delta, if they are all present. + * Returns 1 on success (even if we didn't do anything), and 0 on failure. + */ +int +combine_if_complete(char *delta, int pce, int npieces) + { + int i, e; + int lfd; + struct stat sb; + char pname[PATH_MAX]; + char dname[PATH_MAX]; + char tname[PATH_MAX]; + + /* + * We can probably just rename() it into place if it is a small delta. + */ + if (npieces == 1) + { + mk_delta_name(dname, delta); + mk_piece_name(pname, delta, 1, 1); + if (rename(pname, dname) == 0) + { + chmod(dname, 0666 & ~mask); + err("%s complete", delta); + return 1; + } + } + + /* + * Grab a lock on the reassembly mutex file so that we can be sure we are + * working alone, not fighting another ctm_rmail! + */ + strcpy(tname, delta_dir); + strcat(tname, "/.mutex_build"); + if ((lfd = lock_file(tname)) < 0) + return 0; + + /* + * Are all of the pieces present? Of course the current one is, + * unless all pieces are missing because another ctm_rmail has + * processed them already. + */ + for (i = 1; i <= npieces; i++) + { + if (i == pce) + continue; + mk_piece_name(pname, delta, i, npieces); + if (stat(pname, &sb) < 0) + { + close(lfd); + return 1; + } + } + + /* + * Stick them together. Let combine() use our file name buffers, since + * we're such good buddies. :-) + */ + e = combine(delta, npieces, dname, pname, tname); + close(lfd); + return e; + } + + +/* + * Put the pieces together to form a delta. + * Returns 1 on success, and 0 on failure. + * Note: dname, pname, and tname are room for some file names that just + * happened to by lying around in the calling routine. Waste not, want not! + */ +int +combine(char *delta, int npieces, char *dname, char *pname, char *tname) + { + FILE *dfp, *pfp; + int i, n, e; + char buf[BUFSIZ]; + int fd = -1; + + strcpy(tname, delta_dir); + strcat(tname, "/d.XXXXXXXXXX"); + if ((fd = mkstemp(tname)) == -1 || + (dfp = fdopen(fd, "w")) == NULL) + { + if (fd != -1) { + close(fd); + err("cannot open '%s' for writing", tname); + } + else + err("*mkstemp: '%s'", tname); + return 0; + } + + /* + * Reconstruct the delta by reading each piece in order. + */ + for (i = 1; i <= npieces; i++) + { + mk_piece_name(pname, delta, i, npieces); + if ((pfp = fopen(pname, "r")) == NULL) + { + err("cannot open '%s' for reading", pname); + fclose(dfp); + unlink(tname); + return 0; + } + while ((n = fread(buf, sizeof(char), sizeof(buf), pfp)) != 0) + fwrite(buf, sizeof(char), n, dfp); + e = ferror(pfp); + fclose(pfp); + if (e) + { + err("error reading '%s'", pname); + fclose(dfp); + unlink(tname); + return 0; + } + } + fflush(dfp); + e = ferror(dfp); + fclose(dfp); + if (e) + { + err("error writing '%s'", tname); + unlink(tname); + return 0; + } + + mk_delta_name(dname, delta); + if (rename(tname, dname) < 0) + { + err("*rename: '%s' to '%s'", tname, dname); + unlink(tname); + return 0; + } + chmod(dname, 0666 & ~mask); + + /* + * Throw the pieces away. + */ + for (i = 1; i <= npieces; i++) + { + mk_piece_name(pname, delta, i, npieces); + if (unlink(pname) < 0) + err("*unlink: '%s'", pname); + } + + err("%s complete", delta); + return 1; + } + + +/* + * MIME BASE64 decode table. + */ +static unsigned char from_b64[0x80] = + { + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0x3e, 0xff, 0xff, 0xff, 0x3f, + 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, + 0x3c, 0x3d, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, + 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, + 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, + 0x17, 0x18, 0x19, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, + 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, + 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30, + 0x31, 0x32, 0x33, 0xff, 0xff, 0xff, 0xff, 0xff + }; + + +/* + * Decode a line of ASCII into binary. Returns the number of bytes in + * the output buffer, or < 0 on indigestable input. Error output is + * the negative of the index of the inedible character. + */ +int +decode_line(char *line, char *out_buf) + { + unsigned char *ip = (unsigned char *)line; + unsigned char *op = (unsigned char *)out_buf; + unsigned long bits; + unsigned x; + + for (;;) + { + if (*ip >= 0x80 || (x = from_b64[*ip]) >= 0x40) + break; + bits = x << 18; + ip++; + if (*ip < 0x80 && (x = from_b64[*ip]) < 0x40) + { + bits |= x << 12; + *op++ = bits >> 16; + ip++; + if (*ip < 0x80 && (x = from_b64[*ip]) < 0x40) + { + bits |= x << 6; + *op++ = bits >> 8; + ip++; + if (*ip < 0x80 && (x = from_b64[*ip]) < 0x40) + { + bits |= x; + *op++ = bits; + ip++; + } + } + } + } + + if (*ip == '\0' || *ip == '\n') + return op - (unsigned char *)out_buf; + else + return -(ip - (unsigned char *)line); + } + + +/* + * Create and lock the given file. + * + * Clearing the lock is as simple as closing the file descriptor we return. + */ +int +lock_file(char *name) + { + int lfd; + + if ((lfd = open(name, O_WRONLY|O_CREAT, 0600)) < 0) + { + err("*open: '%s'", name); + return -1; + } + if (flock(lfd, LOCK_EX) < 0) + { + close(lfd); + err("*flock: '%s'", name); + return -1; + } + return lfd; + } |
