diff options
Diffstat (limited to 'networking/sendmail.c')
| -rw-r--r-- | networking/sendmail.c | 563 |
1 files changed, 0 insertions, 563 deletions
diff --git a/networking/sendmail.c b/networking/sendmail.c deleted file mode 100644 index 9602b89..0000000 --- a/networking/sendmail.c +++ /dev/null @@ -1,563 +0,0 @@ -/* vi: set sw=4 ts=4: */ -/* - * bare bones sendmail - * - * Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com> - * - * Licensed under GPLv2, see file LICENSE in this tarball for details. - */ -#include "libbb.h" - -struct globals { - pid_t helper_pid; - unsigned timeout; - FILE *fp0; // initial stdin - // arguments for SSL connection helper - const char *xargs[9]; -}; -#define G (*ptr_to_globals) -#define helper_pid (G.helper_pid) -#define timeout (G.timeout ) -#define fp0 (G.fp0 ) -#define xargs (G.xargs ) -#define INIT_G() do { \ - SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \ - xargs[0] = "openssl"; \ - xargs[1] = "s_client"; \ - xargs[2] = "-quiet"; \ - xargs[3] = "-connect"; \ - /*xargs[4] = "localhost";*/ \ - xargs[5] = "-tls1"; \ - xargs[6] = "-starttls"; \ - xargs[7] = "smtp"; \ -} while (0) - -#define opt_connect (xargs[4]) - -static void uuencode(char *fname, const char *text) -{ - enum { - SRC_BUF_SIZE = 45, /* This *MUST* be a multiple of 3 */ - DST_BUF_SIZE = 4 * ((SRC_BUF_SIZE + 2) / 3), - }; - -#define src_buf text - FILE *fp = fp; - ssize_t len = len; - char dst_buf[DST_BUF_SIZE + 1]; - - if (fname) { - fp = (NOT_LONE_DASH(fname)) ? xfopen_for_read(fname) : fp0; - src_buf = bb_common_bufsiz1; - // N.B. strlen(NULL) segfaults! - } else if (text) { - // though we do not call uuencode(NULL, NULL) explicitly - // still we do not want to break things suddenly - len = strlen(text); - } else - return; - - while (1) { - size_t size; - if (fname) { - size = fread((char *)src_buf, 1, SRC_BUF_SIZE, fp); - if ((ssize_t)size < 0) - bb_perror_msg_and_die(bb_msg_read_error); - } else { - size = len; - if (len > SRC_BUF_SIZE) - size = SRC_BUF_SIZE; - } - if (!size) - break; - // encode the buffer we just read in - bb_uuencode(dst_buf, src_buf, size, bb_uuenc_tbl_base64); - if (fname) { - printf("\r\n"); - } else { - src_buf += size; - len -= size; - } - fwrite(dst_buf, 1, 4 * ((size + 2) / 3), stdout); - } - if (fname) - fclose(fp); -#undef src_buf -} - - -#if ENABLE_FEATURE_SENDMAIL_SSL -static void kill_helper(void) -{ - // TODO!!!: is there more elegant way to terminate child on program failure? - if (helper_pid > 0) - kill(helper_pid, SIGTERM); -} - -// generic signal handler -static void signal_handler(int signo) -{ -#define err signo - if (SIGALRM == signo) { - kill_helper(); - bb_error_msg_and_die("timed out"); - } - - // SIGCHLD. reap zombies - if (wait_any_nohang(&err) > 0) - if (WIFEXITED(err)) { -// if (WEXITSTATUS(err)) - bb_error_msg_and_die("child exited (%d)", WEXITSTATUS(err)); -// else -// kill(0, SIGCONT); - } -#undef err -} - -static void launch_helper(const char **argv) -{ - // setup vanilla unidirectional pipes interchange - int idx; - int pipes[4]; - - xpipe(pipes); - xpipe(pipes+2); - helper_pid = vfork(); - if (helper_pid < 0) - bb_perror_msg_and_die("vfork"); - idx = (!helper_pid) * 2; - xdup2(pipes[idx], STDIN_FILENO); - xdup2(pipes[3-idx], STDOUT_FILENO); - if (ENABLE_FEATURE_CLEAN_UP) - for (int i = 4; --i >= 0; ) - if (pipes[i] > STDOUT_FILENO) - close(pipes[i]); - if (!helper_pid) { - // child: try to execute connection helper - BB_EXECVP(*argv, (char **)argv); - _exit(127); - } - // parent: check whether child is alive - bb_signals(0 - + (1 << SIGCHLD) - + (1 << SIGALRM) - , signal_handler); - signal_handler(SIGCHLD); - // child seems OK -> parent goes on -} -#else -#define kill_helper() ((void)0) -#define launch_helper(x) bb_error_msg_and_die("no SSL support") -#endif - -static const char *command(const char *fmt, const char *param) -{ - const char *msg = fmt; - alarm(timeout); - if (msg) { - msg = xasprintf(fmt, param); - printf("%s\r\n", msg); - } - fflush(stdout); - return msg; -} - -static int smtp_checkp(const char *fmt, const char *param, int code) -{ - char *answer; - const char *msg = command(fmt, param); - // read stdin - // if the string has a form \d\d\d- -- read next string. E.g. EHLO response - // parse first bytes to a number - // if code = -1 then just return this number - // if code != -1 then checks whether the number equals the code - // if not equal -> die saying msg - while ((answer = xmalloc_fgetline(stdin)) != NULL) - if (strlen(answer) <= 3 || '-' != answer[3]) - break; - if (answer) { - int n = atoi(answer); - alarm(0); - free(answer); - if (-1 == code || n == code) - return n; - } - kill_helper(); - bb_error_msg_and_die("%s failed", msg); -} - -static inline int smtp_check(const char *fmt, int code) -{ - return smtp_checkp(fmt, NULL, code); -} - -// strip argument of bad chars -static char *sane(char *str) -{ - char *s = str; - char *p = s; - while (*s) { - if (isalnum(*s) || '_' == *s || '-' == *s || '.' == *s || '@' == *s) { - *p++ = *s; - } - s++; - } - *p = '\0'; - return str; -} - -// NB: parse_url can modify url[] (despite const), but only if '@' is there -static const char *parse_url(const char *url, const char **user, const char **pass) -{ - // parse [user[:pass]@]host - // return host - char *s = strchr(url, '@'); - *user = *pass = NULL; - if (s) { - *s++ = '\0'; - *user = url; - url = s; - s = strchr(*user, ':'); - if (s) { - *s++ = '\0'; - *pass = s; - } - } - return url; -} - -static void rcptto(const char *s) -{ - smtp_checkp("RCPT TO:<%s>", s, 250); -} - -int sendmail_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; -int sendmail_main(int argc UNUSED_PARAM, char **argv) -{ -#if ENABLE_FEATURE_SENDMAIL_MAILX - llist_t *opt_attachments = NULL; - const char *opt_subject; - const char *opt_charset = CONFIG_FEATURE_SENDMAIL_CHARSET; -#if ENABLE_FEATURE_SENDMAIL_MAILXX - llist_t *opt_carboncopies = NULL; - char *opt_errors_to; -#endif -#endif - char *opt_from, *opt_fullname; - const char *opt_user; - const char *opt_pass; - int code; - char *boundary; - llist_t *l; - llist_t *headers = NULL; - char *domain = sane(safe_getdomainname()); - unsigned opts; - - enum { - OPT_w = 1 << 0, // network timeout - OPT_H = 1 << 1, // [user:password@]server[:port] - OPT_S = 1 << 2, // connect using openssl s_client helper - OPT_t = 1 << 3, // read message for recipients - OPT_N = 1 << 4, // request notification - OPT_f = 1 << 5, // sender address - OPT_F = 1 << 6, // sender name, overrides $NAME -#if ENABLE_FEATURE_SENDMAIL_MAILX - OPT_s = 1 << 7, // subject - OPT_j = 1 << 8, // assumed charset - OPT_a = 1 << 9, // attachment(s) -#if ENABLE_FEATURE_SENDMAIL_MAILXX - OPT_c = 1 << 10, // carbon copy - OPT_e = 1 << 11, // errors-to address -#endif -#endif - }; - - // init global variables - INIT_G(); - - // save initial stdin since body is piped! - xdup2(STDIN_FILENO, 3); - fp0 = fdopen(3, "r"); - - // parse options - opt_complementary = "w+:a::" USE_FEATURE_SENDMAIL_MAILXX("c::"); - opts = getopt32(argv, - "w:H:St" "N:f:F:" USE_FEATURE_SENDMAIL_MAILX("s:j:a:") USE_FEATURE_SENDMAIL_MAILXX("c:e:") - "X:V:vq:R:O:o:nmL:Iih:GC:B:b:A:" // postfix compat only, ignored - // r:Q:p:M:Dd are candidates from another man page. TODO? - "46E", // ssmtp introduces another quirks. TODO?: -a[upm] (user, pass, method) to be supported - &timeout /* -w */, &opt_connect /* -H */, - NULL, &opt_from, &opt_fullname, - USE_FEATURE_SENDMAIL_MAILX(&opt_subject, &opt_charset, &opt_attachments,) - USE_FEATURE_SENDMAIL_MAILXX(&opt_carboncopies, &opt_errors_to,) - NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL - ); - //argc -= optind; - argv += optind; - - // connect to server - // host[:port] not specified ? -> use $SMTPHOST. no $SMTPHOST ? -> use localhost - if (!(opts & OPT_H)) { - opt_connect = getenv("SMTPHOST"); - if (!opt_connect) - opt_connect = "127.0.0.1"; - } - // fetch username and password, if any - // NB: parse_url modifies opt_connect[] ONLY if '@' is there. - // Thus "127.0.0.1" won't be modified, an is ok that it is RO. - opt_connect = parse_url(opt_connect, &opt_user, &opt_pass); - - // username must be defined! - if (!opt_user) { - // N.B. IMHO getenv("USER") can be way easily spoofed! - opt_user = bb_getpwuid(NULL, -1, getuid()); - } - - // SSL ordered? -> - if (opts & OPT_S) { - // ... use openssl helper - launch_helper(xargs); - // no SSL ordered? -> - } else { - // ... make plain connect - int fd = create_and_connect_stream_or_die(opt_connect, 25); - // make ourselves a simple IO filter - // from now we know nothing about network :) - xmove_fd(fd, STDIN_FILENO); - xdup2(STDIN_FILENO, STDOUT_FILENO); - } - - // got no sender address? -> use username as a resort - if (!(opts & OPT_f)) { - opt_from = xasprintf("%s@%s", opt_user, domain); - } - - // introduce to server - - // we didn't use SSL helper? -> - if (!(opts & OPT_S)) { - // ... wait for initial server OK - smtp_check(NULL, 220); - } - - // we should start with modern EHLO - if (250 != smtp_checkp("EHLO %s", domain, -1)) { - smtp_checkp("HELO %s", domain, 250); - } - if (ENABLE_FEATURE_CLEAN_UP) - free(domain); - - // set sender - // NOTE: if password has not been specified - // then no authentication is possible - code = (opt_pass ? -1 : 250); - // first try softly without authentication - while (250 != smtp_checkp("MAIL FROM:<%s>", opt_from, code)) { - // MAIL FROM failed -> authentication needed - if (334 == smtp_check("AUTH LOGIN", -1)) { - uuencode(NULL, opt_user); // opt_user != NULL - smtp_check("", 334); - uuencode(NULL, opt_pass); - smtp_check("", 235); - } - // authenticated OK? -> retry to set sender - // but this time die on failure! - code = 250; - } - - // recipients specified as arguments - while (*argv) { - char *s = sane(*argv); - // loose test on email address validity - if (strchr(s, '@')) { - rcptto(s); - llist_add_to_end(&headers, xasprintf("To: %s", s)); - } - argv++; - } - -#if ENABLE_FEATURE_SENDMAIL_MAILXX - // carbon copies recipients specified as -c options - for (l = opt_carboncopies; l; l = l->link) { - char *s = sane(l->data); - // loose test on email address validity - if (strchr(s, '@')) { - rcptto(s); - // TODO: do we ever need to mangle the message? - //llist_add_to_end(&headers, xasprintf("Cc: %s", s)); - } - } -#endif - - // if -t specified or no recipients specified -> read recipients from message - // i.e. scan stdin for To:, Cc:, Bcc: lines ... - // ... and then use the rest of stdin as message body - // N.B. subject read from body can be further overrided with one specified on command line. - // recipients are merged. Bcc: lines are deleted - // N.B. other headers are collected and will be dumped verbatim - if (opts & OPT_t || !headers) { - // fetch recipients and (optionally) subject - char *s; - while ((s = xmalloc_fgetline(fp0)) != NULL) { - if (0 == strncasecmp("To: ", s, 4) || 0 == strncasecmp("Cc: ", s, 4)) { - rcptto(sane(s+4)); - llist_add_to_end(&headers, s); - } else if (0 == strncasecmp("Bcc: ", s, 5)) { - rcptto(sane(s+5)); - free(s); - // N.B. Bcc vanishes from headers! - } else if (0 == strncmp("Subject: ", s, 9)) { - // we read subject -> use it verbatim unless it is specified - // on command line -#if ENABLE_FEATURE_SENDMAIL_MAILX - if (opts & OPT_s) - free(s); - else -#endif - llist_add_to_end(&headers, s); - } else if (s[0]) { - // misc header - llist_add_to_end(&headers, s); - } else { - free(s); - break; // stop on the first empty line - } - } - } - - // enter "put message" mode - smtp_check("DATA", 354); - - // put headers we could have preread with -t - for (l = headers; l; l = l->link) { - printf("%s\r\n", l->data); - if (ENABLE_FEATURE_CLEAN_UP) - free(l->data); - } - - // put (possibly encoded) subject -#if ENABLE_FEATURE_SENDMAIL_MAILX - if (opts & OPT_j) - sane((char *)opt_charset); - if (opts & OPT_s) { - printf("Subject: "); - if (opts & OPT_j) { - printf("=?%s?B?", opt_charset); - uuencode(NULL, opt_subject); - printf("?="); - } else { - printf("%s", opt_subject); - } - printf("\r\n"); - } -#endif - - // put sender name, $NAME is the default - if (!(opts & OPT_F)) - opt_fullname = getenv("NAME"); - if (opt_fullname) - printf("From: \"%s\" <%s>\r\n", opt_fullname, opt_from); - - // put notification - if (opts & OPT_N) - printf("Disposition-Notification-To: %s\r\n", opt_from); - -#if ENABLE_FEATURE_SENDMAIL_MAILXX - // put errors recipient - if (opts & OPT_e) - printf("Errors-To: %s\r\n", opt_errors_to); -#endif - - // make a random string -- it will delimit message parts - srand(monotonic_us()); - boundary = xasprintf("%d-%d-%d", rand(), rand(), rand()); - - // put common headers - // TODO: do we really need this? -// printf("Message-ID: <%s>\r\n", boundary); - -#if ENABLE_FEATURE_SENDMAIL_MAILX - // have attachments? -> compose multipart MIME - if (opt_attachments) { - const char *fmt; - const char *p; - char *q; - - printf( - "Mime-Version: 1.0\r\n" - "%smultipart/mixed; boundary=\"%s\"\r\n" - , "Content-Type: " - , boundary - ); - - // body is pseudo attachment read from stdin in first turn - llist_add_to(&opt_attachments, (char *)"-"); - - // put body + attachment(s) - // N.B. all these weird things just to be tiny - // by reusing string patterns! - fmt = - "\r\n--%s\r\n" - "%stext/plain; charset=%s\r\n" - "%s%s\r\n" - "%s" - ; - p = opt_charset; - q = (char *)""; - l = opt_attachments; - while (l) { - printf( - fmt - , boundary - , "Content-Type: " - , p - , "Content-Disposition: inline" - , q - , "Content-Transfer-Encoding: base64\r\n" - ); - p = ""; - fmt = - "\r\n--%s\r\n" - "%sapplication/octet-stream%s\r\n" - "%s; filename=\"%s\"\r\n" - "%s" - ; - uuencode(l->data, NULL); - l = l->link; - if (l) - q = bb_get_last_path_component_strip(l->data); - } - - // put message terminator - printf("\r\n--%s--\r\n" "\r\n", boundary); - - // no attachments? -> just dump message - } else -#endif - { - char *s; - // terminate headers - printf("\r\n"); - // put plain text respecting leading dots - while ((s = xmalloc_fgetline(fp0)) != NULL) { - // escape leading dots - // N.B. this feature is implied even if no -i (-oi) switch given - // N.B. we need to escape the leading dot regardless of - // whether it is single or not character on the line - if ('.' == s[0] /*&& '\0' == s[1] */) - printf("."); - // dump read line - printf("%s\r\n", s); - } - } - - // leave "put message" mode - smtp_check(".", 250); - // ... and say goodbye - smtp_check("QUIT", 221); - // cleanup - if (ENABLE_FEATURE_CLEAN_UP) - fclose(fp0); - - return EXIT_SUCCESS; -} |