From ddd42cb064b157a2a5d61a922a6ce95ea2f3e4be Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Tue, 29 Jan 2008 00:59:15 +0000 Subject: [PATCH] sendmail: really svn add it --- networking/sendmail.c | 313 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 313 insertions(+) create mode 100644 networking/sendmail.c diff --git a/networking/sendmail.c b/networking/sendmail.c new file mode 100644 index 000000000..2ea10b124 --- /dev/null +++ b/networking/sendmail.c @@ -0,0 +1,313 @@ +/* vi: set sw=4 ts=4: */ +/* + * bare bones sendmail + * + * Copyright (C) 2008 by Vladimir Dronnikov + * + * Licensed under GPLv2, see file LICENSE in this tarball for details. + */ +#include "libbb.h" + +/* + Extracted from BB uuencode.c + */ +enum { + SRC_BUF_SIZE = 45, /* This *MUST* be a multiple of 3 */ + DST_BUF_SIZE = 4 * ((SRC_BUF_SIZE + 2) / 3), +}; + +static void uuencode(const char *fname) +{ + int fd; + char src_buf[SRC_BUF_SIZE]; + char dst_buf[1 + DST_BUF_SIZE + 1]; + + fd = xopen(fname, O_RDONLY); + fflush(stdout); + dst_buf[0] = '\n'; + while (1) { + size_t size = full_read(fd, src_buf, SRC_BUF_SIZE); + if (!size) + break; + if ((ssize_t)size < 0) + bb_perror_msg_and_die(bb_msg_read_error); + /* Encode the buffer we just read in */ + bb_uuencode(dst_buf + 1, src_buf, size, bb_uuenc_tbl_base64); + xwrite(STDOUT_FILENO, dst_buf, 1 + 4 * ((size + 2) / 3)); + } + close(fd); +} + +// "inline" version +// encodes content of given buffer instead of fd +// used to encode subject and authentication terms +static void uuencode_inline(const char *src_buf) +{ + size_t len; + char dst_buf[DST_BUF_SIZE + 1]; + + len = strlen(src_buf); + fflush(stdout); + while (len > 0) { + size_t chunk = (len <= SRC_BUF_SIZE) ? len : SRC_BUF_SIZE; + bb_uuencode(dst_buf, src_buf, chunk, bb_uuenc_tbl_base64); + xwrite(STDOUT_FILENO, dst_buf, 4 * ((chunk + 2) / 3)); + src_buf += chunk; + len -= chunk; + } +} + +#if ENABLE_FEATURE_SENDMAIL_NETWORK +// generic signal handler +static void signal_handler(int signo) +{ + int err; + + if (SIGALRM == signo) + bb_error_msg_and_die("timed out"); + + // SIGCHLD. reap zombies + if (wait_any_nohang(&err) > 0) + if (WIFEXITED(err) && WEXITSTATUS(err)) + bb_error_msg_and_die("child exited (%d)", WEXITSTATUS(err)); +} + +static pid_t helper_pid = -1; + +// read stdin, parses first bytes to a number, i.e. server response +// if code = -1 then just return this number +// if code != -1 then checks whether the number equals the code +// if not equal -> die saying errmsg +static int check(int code, const char *errmsg) +{ + char *answer; + + // read a string and match it against the set of available answers + fflush(stdout); + answer = xmalloc_getline(stdin); + if (answer) { + int n = atoi(answer); + if (-1 == code || n == code) { + free(answer); + return n; + } + } + // TODO!!!: is there more elegant way to terminate child on program failure? + if (helper_pid > 0) + kill(helper_pid, SIGTERM); + if (!answer) + answer = (char*)"EOF"; + else + *strchrnul(answer, '\r') = '\0'; + bb_error_msg_and_die("error at %s: got '%s' instead", errmsg, answer); +} + +static int puts_and_check(const char *msg, int code, const char *errmsg) +{ + puts(msg); + return check(code, errmsg); +} +#endif + +int sendmail_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int sendmail_main(int argc, char **argv) +{ + llist_t *recipients = NULL; + llist_t *bodies = NULL; + llist_t *attachments = NULL; + const char *from; + const char *notify; + const char *subject; + const char *charset = "utf-8"; +#if ENABLE_FEATURE_SENDMAIL_NETWORK + const char *wsecs = "10"; + const char *server = "127.0.0.1"; + const char *port = NULL; + const char *opt_user; + const char *opt_pass; + unsigned timeout; +#endif + char *boundary; + unsigned opts; + enum { + OPT_f = 1 << 0, // sender + OPT_n = 1 << 2, // notification + OPT_s = 1 << 3, // subject given + OPT_d = 1 << 7, // dry run - no networking + OPT_w = 1 << 8, // network timeout + OPT_h = 1 << 9, // server + OPT_p = 1 << 10, // port + OPT_U = 1 << 11, // user specified + OPT_P = 1 << 12, // password specified + }; + + // -f must be specified + // -t, -b, -a may be multiple + opt_complementary = "f:t::b::a::"; + opts = getopt32(argv, + "f:t:n::s:b:a:c:" USE_FEATURE_SENDMAIL_NETWORK("dw:h:p:U:P:"), + &from, &recipients, ¬ify, &subject, &bodies, &attachments, &charset + USE_FEATURE_SENDMAIL_NETWORK(, &wsecs, &server, &port, &opt_user, &opt_pass) + ); + //argc -= optind; + argv += optind; + +//printf("OPTS[%4x]\n", opts); + + // TODO!!!: strip recipients and sender from <> + + // establish connection +#if ENABLE_FEATURE_SENDMAIL_NETWORK + timeout = xatou(wsecs); + if (!(opts & OPT_d)) { + // ask password if we need to and while we're still have terminal + // TODO: get password directly from /dev/tty? or from a secret file? + if ((opts & (OPT_U+OPT_P)) == OPT_U) { + if (!isatty(STDIN_FILENO) || !(opt_pass = bb_askpass(0, "Password: "))) { + bb_error_msg_and_die("no password"); + } + } +//printf("OPTS[%4x][%s][%s]\n", opts, opt_user, opt_pass); +//exit(0); + // set chat timeout + alarm(timeout); + // connect to server + if (argv[0]) { + // if connection helper given + // setup vanilla unidirectional pipes interchange + int pipes[4]; + xpipe(pipes); + xpipe(pipes+2); + helper_pid = vfork(); + if (helper_pid < 0) + bb_perror_msg_and_die("vfork"); + xdup2(pipes[(helper_pid)?0:2], STDIN_FILENO); + xdup2(pipes[(helper_pid)?3:1], STDOUT_FILENO); + if (ENABLE_FEATURE_CLEAN_UP) + for (int i = 4; --i >= 0; ) + if (pipes[i] > STDOUT_FILENO) + close(pipes[i]); + // replace child with connection helper + if (!helper_pid) { + // child - try to execute connection helper + BB_EXECVP(argv[0], argv); + _exit(127); + } + // parent - check whether child is alive + sig_catch(SIGCHLD, signal_handler); + sig_catch(SIGALRM, signal_handler); + signal_handler(SIGCHLD); + // child seems OK -> parent goes on SMTP chat + } else { + // no connection helper provided -> make plain connect + int fd = create_and_connect_stream_or_die( + server, + bb_lookup_port(port, "tcp", 25) + ); + xmove_fd(fd, STDIN_FILENO); + xdup2(STDIN_FILENO, STDOUT_FILENO); + // wait for OK + check(220, "INIT"); + } + // mail user specified? try modern AUTHentication + if (opt_user && (334 == puts_and_check("auth login", -1, "auth login"))) { + uuencode_inline(opt_user); + puts_and_check("", 334, "AUTH"); + uuencode_inline(opt_pass); + puts_and_check("", 235, "AUTH"); + // no mail user specified or modern AUTHentication is not supported? + } else { + // fallback to simple HELO authentication + // fetch domain name (defaults to local) + const char *domain = strchr(from, '@'); + if (domain) + domain++; + else + domain = "local"; + printf("helo %s\n", domain); + check(250, "HELO"); + } + + // set addresses + printf("mail from:<%s>\n", from); + check(250, "MAIL FROM"); + for (llist_t *to = recipients; to; to = to->link) { + printf("rcpt to:<%s>\n", to->data); + check(250, "RCPT TO"); + } + puts_and_check("data", 354, "DATA"); + // no timeout while sending message + alarm(0); + } +#endif + + // now put message + // put address headers + printf("From: %s\n", from); + for (llist_t *to = recipients; to; to = to->link) { + printf("To: %s\n", to->data); + } + // put encoded subject + if (opts & OPT_s) { + printf("Subject: =?%s?B?", charset); + uuencode_inline(subject); + puts("?="); + } + // put notification + if (opts & OPT_n) { + const char *s = notify; + if (!s[0]) + s = from; // notify sender by default + printf("Disposition-Notification-To: %s\n", s); + } + // put common headers and body start + //srand(?); + boundary = xasprintf("%d-%d-%d", rand(), rand(), rand()); + printf( + "X-Mailer: busybox " BB_VER " sendmail\n" + "X-Priority: 3\n" + "Message-ID: <%s>\n" + "Mime-Version: 1.0\n" + "Content-Type: multipart/mixed; boundary=\"%s\"\n" + "\n" + "--%s\n" + "Content-Type: text/plain; charset=%s\n" + "%s\n%s" + , boundary, boundary, boundary, charset + , "Content-Disposition: inline" + , "Content-Transfer-Encoding: base64\n" + ); + // put body(ies) + for (llist_t *f = bodies; f; f = f->link) { + uuencode(f->data); + } + // put attachment(s) + for (llist_t *f = attachments; f; f = f->link) { + printf( + "\n--%s\n" + "Content-Type: application/octet-stream\n" + "%s; filename=\"%s\"\n" + "%s" + , boundary + , "Content-Disposition: inline" + , bb_get_last_path_component_strip(f->data) + , "Content-Transfer-Encoding: base64\n" + ); + uuencode(f->data); + } + // put terminator + printf("\n--%s--\n\n", boundary); + if (ENABLE_FEATURE_CLEAN_UP) + free(boundary); + +#if ENABLE_FEATURE_SENDMAIL_NETWORK + // end message and say goodbye + if (!(opts & OPT_d)) { + alarm(timeout); + puts_and_check(".", 250, "BODY"); + puts_and_check("quit", 221, "QUIT"); + } +#endif + + return 0; +}