-/*
- * sendfrom.c -- postproc that selects user, and then mail server, from draft
- *
- * Author: David Levine <levinedl@acm.org>
- *
- * This program fits between send(1) and post(1), as a postproc. It makes
- * up for the facts that send doesn't parse the message draft and post
- * doesn't load the profile.
- *
- * To use:
- *
- * 1) Add profile entries of the form:
- *
- * sendfrom-<email address or domain name>: <post(1) switches>
- *
- * The email address is extracted from the From: header line of the message draft. Multiple
- * profile entries, with different email addresses or domain names, are supported. This
- * allows different switches to post(1), such as -user, to be associated with different email
- * addresses. If a domain name is used, it matches all users in that domain.
- *
- * Example profile entry using OAuth for account hosted by gmail:
- *
- * sendfrom-gmail_address@example.com: -saslmech xoauth2 -authservice gmail -tls
- * -server smtp.gmail.com -user gmail_login@example.com
- *
- * (Indentation indicates a continued line, as supported in MH profiles.) The username
- * need not be the same as the sender address, which was extracted from the From: header line.
- *
- * Example profile entries that use an nmh credentials file:
- *
- * credentials: file:nmhcreds
- * sendfrom-sendgrid_address@example.com: -sasl -tls -server smtp.sendgrid.net
- * sendfrom-outbound.att.net: -sasl -initialtls -server outbound.att.net -port 465
- * sendfrom-fastmail.com: -initialtls -sasl -saslmech LOGIN
- * -server smtps-proxy.messagingengine.com -port 80
- *
- * where nmhcreds is in the user's nmh directory (from the Path profile component) and contains:
- *
- * machine smtp.sendgrid.net
- * login sendgrid_login@example.com
- * password ********
- * machine outbound.att.net
- * login att_login@example.com
- * password ********
- * machine smtps-proxy.messagingengine.com
- * login fastmail_login@example.com
- * password ********
- *
- * 2) To enable, add a line like this to your profile:
- *
- * postproc: <docdir>/contrib/sendfrom
- *
- * with <docdir> expanded. This source file is in docdir. Also, "mhparam docdir" will show it.
- *
- * For more information on authentication to mail servers, see mhlogin(1) for OAuth
- * services, and mh-profile(5) for login credentials.
- *
- * This program follows these steps:
- * 1) Loads profile.
- * 2) Saves command line arguments in vec.
- * 3) Extracts address and domain name from From: header line in draft.
- * 4) Extracts any address or host specific switches to post(1) from profile. Appends
- to vec, along with implied switches, such as OAUTH access token.
- * 5) Calls post, or with -dryrun, echos how it would be called.
- */
-
-#include <h/mh.h>
-#include <h/fmt_scan.h>
-#include <h/fmt_compile.h>
-#include <h/utils.h>
-
-#ifdef OAUTH_SUPPORT
-#include <h/oauth.h>
-
-static int setup_oauth_params(char *vec[], int *, int, const char **);
-#endif /* OAUTH_SUPPORT */
-
-extern char *mhlibexecdir; /* from config.c */
-
-static int get_from_header_info(const char *, const char **, const char **, const char **);
-static const char *get_message_header_info(FILE *, char *);
-static void merge_profile_entry(const char *, const char *, char *vec[], int *vecp);
-static int run_program(char *, char **);
-
-int
-main(int argc, char **argv) {
- /* Make sure that nmh's post gets called by specifying its full path. */
- char *realpost = concat(mhlibexecdir, "/", "post", NULL);
- int whom = 0, dryrun = 0, snoop = 0;
- char **arguments, **argp;
- char *program, **vec;
- int vecp = 0;
- char *msg = NULL;
-
- /* Load profile. */
- if (nmh_init(argv[0], 1)) { return NOTOK; }
-
- /* Save command line arguments in vec, except for the last argument, if it's the draft file path. */
- vec = argsplit(realpost, &program, &vecp);
- for (argp = arguments = getarguments(invo_name, argc, argv, 1); *argp; ++argp) {
- /* Don't pass -dryrun to post by putting it in vec. */
- if (strcmp(*argp, "-dryrun") == 0) {
- dryrun = 1;
- } else {
- vec[vecp++] = getcpy(*argp);
-
- if (strcmp(*argp, "-snoop") == 0) {
- snoop = 1;
- } else if (strcmp(*argp, "-whom") == 0) {
- whom = 1;
- } else {
- /* Need to keep filename, from last arg (though it's not used below with -whom). */
- msg = *argp;
- }
- }
- }
-
- free(arguments);
-
- if (! whom && msg == NULL) {
- adios(NULL, "requires exactly 1 filename argument");
- } else {
- char **vp;
-
- /* With post, but without -whom, need to keep filename as last arg. */
- if (! whom) {
- /* At this point, vecp points to the next argument to be added. Back it up to
- remove the last one, which is the filename. Add it back at the end of vec below. */
- free(vec[--vecp]);
- }
- /* Null terminate vec because it's used below. */
- vec[vecp] = NULL;
-
- if (! whom) {
- /* Some users might need the switch from the profile entry with -whom, but that would
- require figuring out which command line argument has the filename. With -whom, it's
- not necessarily the last one. */
-
- const char *addr, *host;
- const char *message;
-
- /* Extract address and host from From: header line in draft. */
- if (get_from_header_info(msg, &addr, &host, &message) != OK) {
- adios(msg, message);
- }
-
- /* Merge in any address or host specific switches to post(1) from profile. */
- merge_profile_entry(addr, host, vec, &vecp);
- free((void *) host);
- free((void *) addr);
- }
-
- vec[vecp] = NULL;
- for (vp = vec; *vp; ++vp) {
- if (strcmp(*vp, "xoauth2") == 0) {
-#ifdef OAUTH_SUPPORT
- const char *message;
-
- if (setup_oauth_params(vec, &vecp, snoop, &message) != OK) {
- adios(NULL, message);
- }
- break;
-#else
- NMH_UNUSED(snoop);
- NMH_UNUSED(vp);
- adios(NULL, "sendfrom built without OAUTH_SUPPORT, so -saslmech xoauth2 is not supported");
-#endif /* OAUTH_SUPPORT */
- }
- }
-
- if (! whom) {
- /* Append filename as last non-null vec entry. */
- vec[vecp++] = getcpy(msg);
- vec[vecp] = NULL;
- }
-
- /* Call post, or with -dryrun, echo how it would be called. */
- if (dryrun) {
- /* Show the program name, because run_program() won't. */
- printf("%s ", realpost);
- fflush(stdout);
- }
- if (run_program(dryrun ? "echo" : realpost, vec) != OK) {
- adios(realpost, "failure in ");
- }
-
- arglist_free(program, vec);
- free(realpost);
- }
-
- return 0;
-}
-
-
-
-#ifdef OAUTH_SUPPORT
-/*
- * For XOAUTH2, append access token, from mh_oauth_do_xoauth(), for the user to vec.
- */
-static
-int
-setup_oauth_params(char *vec[], int *vecp, int snoop, const char **message) {
- const char *saslmech = NULL, *user = NULL, *auth_svc = NULL;
- int i;
-
- /* Make sure we have all the information we need. */
- for (i = 1; i < *vecp; ++i) {
- /* Don't support abbreviated switches, to avoid collisions in the future if new ones
- are added. */
- if (! strcmp(vec[i-1], "-saslmech")) {
- saslmech = vec[i];
- } else if (! strcmp(vec[i-1], "-user")) {
- user = vec[i];
- } else if (! strcmp(vec[i-1], "-authservice")) {
- auth_svc = vec[i];
- }
- }
-
- if (auth_svc == NULL) {
- if (saslmech && ! strcasecmp(saslmech, "xoauth2")) {
- *message = "must specify -authservice with -saslmech xoauth2";
- return NOTOK;
- }
- } else {
- if (user == NULL) {
- *message = "must specify -user with -saslmech xoauth2";
- return NOTOK;
- }
-
- vec[(*vecp)++] = getcpy("-authservice");
- if (saslmech && ! strcasecmp(saslmech, "xoauth2")) {
- vec[(*vecp)++] = mh_oauth_do_xoauth(user, auth_svc, snoop ? stderr : NULL);
- } else {
- vec[(*vecp)++] = getcpy(auth_svc);
- }
- }
-
- return 0;
-}
-#endif /* OAUTH_SUPPORT */
-
-
-/*
- * Extract user and domain from From: header line in draft.
- */
-static
-int
-get_from_header_info(const char *filename, const char **addr, const char **host, const char **message) {
- struct stat st;
- FILE *in;
-
- if (stat (filename, &st) == NOTOK) {
- *message = "unable to stat draft file";
- return NOTOK;
- }
-
- if ((in = fopen(filename, "r")) != NULL) {
- char *addrformat = "%(addr{from})", *hostformat = "%(host{from})";
-
- if ((*addr = get_message_header_info(in, addrformat)) == NULL) {
- *message = "unable to find From: address in";
- return NOTOK;
- }
- rewind(in);
-
- if ((*host = get_message_header_info(in, hostformat)) == NULL) {
- fclose(in);
- *message = "unable to find From: host in";
- return NOTOK;
- }
- fclose(in);
-
- return OK;
- } else {
- *message = "unable to open";
- return NOTOK;
- }
-}
-
-
-/*
- * Get formatted information from header of a message.
- * Adapted from process_single_file() in uip/fmttest.c.
- */
-static
-const char *
-get_message_header_info(FILE *in, char *format) {
- int dat[5];
- struct format *fmt;
- struct stat st;
- int parsing_header;
- m_getfld_state_t gstate = 0;
- charstring_t buffer = charstring_create(0);
- char *retval;
-
- dat[0] = dat[1] = dat[4] = 0;
- dat[2] = fstat(fileno(in), &st) == 0 ? st.st_size : 0;
- dat[3] = INT_MAX;
-
- (void) fmt_compile(new_fs(NULL, NULL, format), &fmt, 1);
- free_fs();
-
- /*
- * Read in the message and process the header.
- */
- parsing_header = 1;
- do {
- char name[NAMESZ], rbuf[NMH_BUFSIZ];
- int bufsz = sizeof rbuf;
- int state = m_getfld(&gstate, name, rbuf, &bufsz, in);
-
- switch (state) {
- case FLD:
- case FLDPLUS: {
- int bucket = fmt_addcomptext(name, rbuf);
-
- if (bucket != -1) {
- while (state == FLDPLUS) {
- bufsz = sizeof rbuf;
- state = m_getfld(&gstate, name, rbuf, &bufsz, in);
- fmt_appendcomp(bucket, name, rbuf);
- }
- }
-
- while (state == FLDPLUS) {
- bufsz = sizeof rbuf;
- state = m_getfld(&gstate, name, rbuf, &bufsz, in);
- }
- break;
- }
- default:
- parsing_header = 0;
- }
- } while (parsing_header);
- m_getfld_state_destroy(&gstate);
-
- fmt_scan(fmt, buffer, INT_MAX, dat, NULL);
- fmt_free(fmt, 1);
-
- /* Trim trailing newline, if any. */
- retval = rtrim(charstring_buffer_copy((buffer)));
- charstring_free(buffer);
-
- return retval;
-}
-
-
-/*
- * Look in profile for entry corresponding to addr or host, and add its contents to vec.
- *
- * Could do some of this automatically, by looking for:
- * 1) access-$(mbox{from}) in oauth-svc file using mh_oauth_cred_load(), which isn't
- * static and doesn't have side effects; free the result with mh_oauth_cred_free())
- * 2) machine $(mbox{from}) in creds
- * If no -server passed in from profile or commandline, could use smtp.<svc>.com for gmail,
- * but that might not generalize for other svcs.
- */
-static
-void
-merge_profile_entry(const char *addr, const char *host, char *vec[], int *vecp) {
- char *addr_entry = concat("sendfrom-", addr, NULL);
- char *profile_entry = context_find(addr_entry);
-
- free(addr_entry);
- if (profile_entry == NULL) {
- /* No entry for the user. Look for one for the host. */
- char *host_entry = concat("sendfrom-", host, NULL);
-
- profile_entry = context_find(host_entry);
- free(host_entry);
- }
-
- /* Use argsplit() to do the real work of splitting the args in the profile entry. */
- if (profile_entry && strlen(profile_entry) > 0) {
- int profile_vecp;
- char *file;
- char **profile_vec = argsplit(profile_entry, &file, &profile_vecp);
- int i;
-
- for (i = 0; i < profile_vecp; ++i) {
- vec[(*vecp)++] = getcpy(profile_vec[i]);
- }
-
- arglist_free(file, profile_vec);
- }
-}
-
-
-/*
- * Fork and exec.
- */
-static
-int
-run_program(char *realpost, char **vec) {
- pid_t child_id;
- int i;
-
- for (i = 0; (child_id = fork()) == NOTOK && i < 5; ++i) { sleep(5); }
-
- switch (child_id) {
- case -1:
- /* oops -- fork error */
- return NOTOK;
- case 0:
- (void) execvp(realpost, vec);
- fprintf(stderr, "unable to exec ");
- perror(realpost);
- _exit(-1);
- default:
- if (pidXwait(child_id, realpost)) {
- return NOTOK;
- }
- }
-
- return OK;
-}
projects / nmh / commitdiff